Whither Co-fermentaton ?

There are many practical reasons to co-ferment that historically have weighted heavily in favor of doing so.

Historically perhaps the most frequent instance of co-fermentation of different grape varieties is when there is a field blend in the vineyard. These field blends are normally planted on fairly small plots and the existence of several grape varieties planted apparently at random seems very much a part of the terroir.  Even if one wanted to separate out the varieties it may not have been practical to do so. 

Although of course many field blends may have been planted out of sheer expedience or what was then available to be planted, there may of course be considered reasons why the field blend contains two or more varieties. One thinks of Cote Rotie for example , where a portion of Viognier may be included in the vineyard among the predominant Syrah. These white Viognier grapes are tossed into the vat together with the red grapes, because it is thought that their inclusion makes a positive contribution to the final wine - Viognier’s silky mouthfeel and expressive aromatics moderate some of Syrah’s more brutish tones.

There are, however, additional but less evident benefits to co-fermentation than simply blending the qualities that each individual grape variety contributes. For example, the presence of even small proportions of Viognier have been shown to stabilize the color of the Syrah. Ridge Vineyards have done analysis on this subject and conclude  -“ the theory is that viognier helps stabilize syrah’s color; the condensation reactions between viognier’s flavanols and syrah’s anthocyanins form highly stable polymerized molecules that stay with the wine for life. Once these polymers form, they don’t degrade through normal oxidation reactions.”  The inclusion of Viognier may also slightly change the color of the Syrah towards the bluer side of the color spectrum.  But regardless of how it is now justified through today’s better understanding of the chemistry involved, it has been the case for many decades that co-fermentation of these two grape varieties in the Northern Rhone was thought simply to produce better wine. Co-fermentation may also favorably impact aromatics of both varieties. So there are reasons to do it beyond simply convenience and what each grape varietal intrinsically contributes to the blend - and in the case of some classic combinations of grapes these reasons now seem to have scientific explanation. 

The presumption, however, is that one is harvesting these grapes at the same time - and therein lies a certain loss of control if the grape varieties do in fact ripen at different times.  In the case of field blends this loss of control is something one evidently sacrifices. 

More common has been the co-fermentation of various plots of the same grape variety. In times of old this would not even have been considered co-fermentation. Even today this is done for expedience based on the size of fermentation vats available. Available space is in practice a major constraining factor in many cellars. If you don’t have small vats that can allow for fermenting different plots separately, you have little option but to toss everything into the larger vats. This does not necessarily mean that you have to harvest all the plots at the precisely the same time. Grapes from an earlier picked plot can be undergoing fermentation in the large vessel for a few days before additional grapes are added from a different plot that was harvested later.  But there are limitations to this. You cannot wait too long. Quoting from Alan Manley’s M8 website, referring to Barolo - “As each vineyard matures and is harvested, the fruit is added to tanks with fruit already in fermentation. This is called a “continuous ferment” and has fallen out of general use, but is consistent with older, traditional winemaking practices in this region”. Yet Alan, in composing is Barolo blend, has of late had to vinify his Monforte fruit separately, since this can ripen fully two weeks after the fruit from his newly acquired other vineyards, which prohibits co-fermentation of everything together in the continuous ferment manner, however much that may be desired. So even if one co-ferments when one can, there are practical limits. 

Beyond tolerances of a few days, co-fermentation results in loss of control as to optimal picking dates and of course any thought of holding back - and omitting from the blend entirely - any parcel whose grapes perhaps underperformed that year.  

Given the increased financial resources of winemakers who make wines from regions that now command high prices, the trend has been to equip cellars to allow for separate fermentation of many different plots in the larger vineyard holdings by having not just many fermentation vats but having them in many sizes, so they can operate optimally (by reason of their particular shape) on the quantity of grapes harvested from any particular plot. One has only to visit the cellar at Cheval Blanc in St Emilion to see the lengths to which this is now the mantra. Having precise control over harvest date and the ability to decide whether to include or exclude wine from any particular parcel in the final blend is today highly valued. A very great deal of money has been spent equipping modern cellars to have this capability, reflecting the heightened view of picking dates as one of the most important influences on wine quality.

Co-fermentation does of course preclude eliminating any parcels later.  For those who do not wish to eliminate parcels, co-fermentation is fine if the harvest dates allow for it. Maria Teresa Mascarello, at Cantina Mascarello in Barolo, for example, as I understand it will co-ferment wine from their four or five different vineyards because they take the view that the final wine requires the inclusion of all of these without exception and the harvest dates are close enough to allow for co-fermentation.  The final blend is made up of what nature gives them in yield from each parcel. Others, as a matter of doctrine, will vinify parcels separately and still elect never to eliminate any parcel from the final blend on the basis that the terroir sought to be reflected in the bottle includes all the parcels. Thus no parcel should be eliminated. Domaine Chave take this approach, though in their case not the full amount of each parcel is necessarily included in the final wine. But each parcel will be present to some degree. But parcels are vinified separately to allow for optimal picking dates / elevage in the hope of improving the quality of wine from each distinct parcel before blending. Others vinify separately and then will eliminate sub par parcels entirely. This is particularly common where the estate has a second wine and there are dozens of separately vinified parcels.  All these separate vinifications, driven out of a desire to control picking dates and subsequent elevage precisely, make the art of blending an increasingly relevant skill. But it also comes at whatever is the cost of not co-fermenting.

The picture is of Viognier and Syrah grapes ready for co-fermentation

The Mystery of Malolactic

It used to be of course, when malolactic fermentation was less well understood, that winemakers just let the process take its natural course and hoped for the best. With greater understanding of the science has come a desire if not actually to control it, at least have it take place in a way that is optimal and with the least risk of damaging the wine. But there seem to be quite different views as to how best to achieve those ends.

For whites of course whether to allow the wine to undergo malolactic is primarily driven by the style of wine one his trying to make.  Going through malolactic will reduce the sensation of harsh acid in the wine - and indeed raise it’s pH measure - and the by-product flavors produced give a creaminess to the wine’s texture. As you might expect, where the winemaker is seeking to make a crisp wine at cool temperatures with good freshness the malolactic process is likely to be blocked. Conversely, if the wine has searingly high acid and would benefit from a higher pH and more textured mouthfeel to compensate, the malolactic fermentation conversion process will be allowed to proceed.

For whites, therefore, whether the wine goes through malolactic seems a fairly straightforward decision - it is a style choice. Some Champagne houses block malolactic and some do not. Some winemakers, wanting to preserve the acid quality, block malolactic but find other ways to give more richness to the wine - such as having the wine rest for long periods in oak on its lees. In still other cases high levels of fruit ripeness may make adding further texture by running the wine through malolactic undesirable.  And so it goes.  The “Yes/No/Partially” decision for whites is purely a style choice and will depend on vintage and grape variety.

But at another lev this is a process that requires considerable care in decision making.  For reds the reduction in pH resulting from malolactic fermentation is far less than for whites. The principal benefit of having a red wine go through malolactic is the increase in texture that the biological process imparts to the tannins and the improved color intensity of the wine. The wine seems more supple and to have a broader mouthfeel. So pretty much every red wine goes though malolactic.  Emile Peynaud was of the view, as expressed in a paper in as early as 1939, that “it is not exaggerating to say that without malolactic fermentation there would be hardly any great reds of Bordeaux”.  But it really was not until the late 1960s that the process was properly understood. 

Even today, the malolactic fermentation can be a period of some risk to the health of the wine. As with primary fermentation, it is not without its own concerns. Not only are there four different strains of bacteria that can perform the job ( but only one you really want to do it) each of these does not produce the same bi-products. And wine - being high in acid and alcohol - is hardly an environment best suited to the growth of the desired bacteria. If there is still sugar left in the must then the wrong strain of bacteria can produce volatile acidity. So there are some things to worry about. Having decided that the red wine is to go through malolactic, one is left having to decide when, in what vessel and for how long to allow it to take place. Not too much in this space can actually be proven to have benefits or mitigate risk, which makes it difficult to say there is a single better way and a worse way or time to perform malolactic. Extraneous conditions will also matter, in particular how cool is one’s cellar in the relevant season when malolactic is targeted to occur. But many well known and respected growers have expressed differing preferences on these matters, depending on which desired consequence or risk reduction they regard as paramount. Which reinforces that there likely is no single “right” way to do malolactic.

I set out below some of these variables. 

Vessel. Certainly for Nebbiolo, allowing the malolactic to take place in small new oak barrels does seem to me to influence the wine considerably. The wines seem quite marked by the barrel. Those who use new or partially new barrique for aging the wine more generally, likely also have the malolactic take place in those same barrels. This is common in Bordeaux also. The technical management at Smith Haut Lafitte believe that it is preferred to do malolactic in small barrel because it results in superior integration of oak tannin - presumably a valid point of view if you are using new oak and wish to impart tannin from the wood to the wine.  Others prefer the wine to be housed in larger inert vessels during malolactic and will rack the wine into these during the process, then move the wine back into wood afterwards. So there are differing views as to choice of vessel, which perhaps can be categorized as either preferring the influence of smaller wood during malolactic or not.

Timing. In Bordeaux the malolactic is often encouraged to occur early, not least because the Bordelaise want the wines to be fully presentable for the April “En Primeur” tasting season. So they heat the cellars to induce malolactic to start. Many in Burgundy also prefer early malolactic - most famously at Domaine Rousseau. There is an argument in support of this that an early malolactic allows the wine subsequently to rest on lees that include post malolactic bacteria for a longer period prior to bottling than if malolactic occurs later. Benjamin Leroux has suggested it may be optimally beneficial for the time on lees to be post malolactic ie post conversion of the malic acid to lactic acid and in the presence of the bi-products resulting from that conversion having already taken place. Today, with so many warmer vintages, there is less malic acid in the grapes and so fewer residual by-products result from the conversion. So the risk of contamination through the malolactic process and subsequently retaining those by-products with the lees is correspondingly reduced. The “dead” bacterial population is simply lower. In contrast, most rack the wine after malolactic precisely to eliminate any potentially adverse bi-products from the malolactic. Others prefer the malolactic to occur later. In this camp we have Jeremy Seysses and Christophe Roumier, who takes the position a later malolactic allows for it to progress more slowly and generates better color retention. And since you have to sulphur the wine after malolactic the less time between the malolactic’s end and bottling the less total sulphur must be added. Christophe Roumier himself is also pretty sure a later and longer malolactic reduces the risk of volatile acidity. But there seems to be no consensus as to timing.

Duration.  In relation to cooler cellars, you sometimes hear stories of wine still going through malolactic for the better part of a year.  Some prefer the process to take place in its own time and are willing to let it run an extended course. Others prefer it be brief - recognizing that the process is an unsettling period for the wine and a time that is not without risk. 

No consumer today says “ I prefer wines that have gone through late malolactic” or “I prefer wines where the malolactic was completed early and quickly” because I submit it is quite difficult in later tasting the resulting wine to infer precisely how the malolactic was conducted. Nor is there is yet even consensus as to the actual consequences of malolactic having taken place in a particular vessel or early or late or for a particular duration. Yet the growers themselves all do have preferences. They have to have because they must make decisions relating to these variables. For the time being, to the consumer, optimally managing malolactic is in that category of the dozens of unseen decisions a wine maker has to make, which in aggregate distinguish the competent from the great. As to further attributing consequence to winemakers’ every decision, in the context of the issue of malolactic the endlessly curious consumer may just have to admit defeat. Which is just fine with me.

Magical Yeasts

If I was ever obliged to write a real thesis or research paper in the context of wine I think I would chose yeasts as the subject.  Perhaps for my own sanity it is as well that I have never undertaken such a task, but I have always found yeasts fascinating.  Here is a fungus on which simply everything in the glass utterly depends. 

Yeasts are sourced from many places. To some limited degree they come from the grapes in the vineyard. Each year fresh yeasts arrive though the goodness of wasps, that transfer yeasts into the grape when they bite into them. Yeast from the actual surface of the berries - mostly but not only of the Saccaromyces type - make a relatively small contribution to the overall yeast population that will involve itself in fermentation, but yeasts can be cultured from these wild vineyard yeasts. Secondly, yeast are also resident in the cellar itself - ambient in the air and on surfaces and tools - and in this capacity can be present of course over many years. Sourced from vineyard or cellar these are described as “wild” or “ambient” yeasts and can be of many types in addition to from the Saccaromyces genus - Kloeckera or Candida or Pichea for example. They can also be Brettanomyces, which can be ominous ( and quite hard to get rid of if unwelcome residents in the cellar). 

But yeasts can also be purchased in packets as ‘commercial yeasts”, which are nurtured elsewhere in large quantities and have particular properties as to the flavor or texture imparted to the wine or its ability to ferment must at high alcohol levels, which may de desirable.  Commercial yeasts of course are far more reliable in achieving the objective, but impart no local identity to the wine. Some would say they do worse - actually remove it.

It may be worth noting that when a winemaker says he uses “natural” yeast, this does not necessarily mean he does not add yeast to the must - but that what is added is not a widely available commercially manufactured yeast.  Yeasts that have been extracted from the local environment can be isolated and cultured, so they can be added to the must to initiate ad achieve fermentation. In larger wine regions, viticultural research departments of local Universities help create these. This is very common practice - Barale in Barolo for example do this. Some of these yeasts are available for selected purchase by others. These yeast of course, so the argument runs, retain the local terroir. Alternatively, what is added could be yeast from an already fermenting vat - a pied de cuve, previously inoculated with such local yeast. Simply add some already fermenting wine to kick start the fermentation. All these yeasts are described as “natural” but are actually added to the must. Those who do not add anything - relying on yeasts on the grapes themselves and ambient yeasts in the cellar to do the job, are said to use “spontaneous fermentation”. Spontaneous fermentation is much admired by some but of course comes at considerable risk.  Until you have a lot of experience, you simply don’t know what you are getting. All yeasts have some by products - esters, aldehydes and types of sulphur compounds. These are volatile compounds and can impact wine aromas especially. Some can be nasty. 

Yeasts of course turn sugar into alcohol and carbon dioxide that reaction gives off heat. The important thing to know is that all yeasts fail to perform this function under certain conditions - such as when there is too much alcohol in the solution or when there is too much Sulphur Dioxide present - but that the particular conditions that prove toxic to the yeast vary by yeast type. Critically, most yeasts actually can no longer perform the chemical transaction when in alcohol levels of much above 3.5% alcohol by volume (ABV). One type can only function when alcohol levels are in the mid range - between say 6% and 9% by ABV. The one yeast that can operate at higher ABVs is the one we are all taught to know in WSET class - the “sugar loving” yeast Saccaromyces Cerevisiae. This yeast can function until the alcohol solution gets to about 15% ABV ( as a technical matter It has been shown to be able to tolerate even higher ABV). This means that many of the yeast types in the vineyard and ambient in the cellar contribute to the alcoholic conversion only for about the first quarter of that process, after which the alcohol level is too toxic for them to continue. At that point - and likely before - Saccaromyces Cerevisiae becomes the dominant yeast, taking the fermentation from that early stage all the way to its conclusion. Saccaromyces Cerevisiae, of course could be a type of ambient yeast, influenced by the local aspect of vineyard and cellar.  It is just worth noting that the many other strains of yeast present likely contribute only at the early stage of the fermentation. So if a multitude of varying ambient yeasts are to contribute to a more precise sense of terroir, it is mostly in that early stage of fermentation that this impact occurs.  Knowing this may influence a winemakers decisions - such as not to do a long pre fermentation cold soak under a lot of sulphur. 

It is said that the yeast’s origin makes a great deal of difference. Many believe for a wine to be a true expression of terroir, there can be no commercial yeasts involved. For these observers, not using commercial yeasts is a point of real differentiation in wine quality, in the same way as not filtering or not chaptalising or not using too much new oak is to others. Natural yeasts are at the very core of a wines identity and authenticity. It is not hard to find winemakers who sign up to the importance of using natural yeasts - Jacques Selosse in Champagne is a vocal example, just to name one. There are some importers who will not import wine made with commercial yeasts - Louis Dressner is an example, I believe. There are  journalist  and critics who feel very strongly on the point - Andrew Jefford is one. Some wine stores basically will not stock wines which have seen commercial yeasts - Chambers Street Wines in New York for example. There are many instances that illustrate the strength of conviction that is held on the issue across the whole spectrum of the wine industry.

In support of the contention that the individual yeast impact the resulting wine, there is chemical evidence that shows considerable variation in the effect of yeasts when measured by the amount of by-products they produce during fermentation. The substances involved certainly suggest a relevance to the end product - including for example, glycerol and types of acid and phenols. And there ei sas ou would expect a great deal of empirical evidence. There are simply too many good makers and good tasters of wine who hold this opinion on the importance of natural yeasts to be wrong. It certainly seems to be the case that grapes from Gevrey Chambertin, for example, vinified in a cellar that has for many years only vinified grapes from Chambolle Musigny, will be influenced by those ambient yeasts in the Chambolle cellar to create a wine that is not quite the same as when those same Gevrey grapes are vinified in a cellar of long standing in Gevrey.  Empirical evidence for this comes from growers who have on occasion swapped grapes between them, of which over the years there have now been many instances. Such is the influence of wild and ambient yeasts.  And M. Millet, after 35 vintages of vinifying separate parcels of Musigny with ambient yeasts, asserted in an interview with Jasper Morris for 67 Pall Mall in June 2021 that each fermentation vat can produce a slightly different wine even though the soil from which the grapes are sourced is almost identical. He attributes these variations to the unique interaction of the yeasts on the must in each fermentation vat. Each fermentation with ambient yeasts is unique and produces subtly different outcomes.

Such a simple organism. Still not completely understood. Producing such magical results. 

Picture Credit - Melba Photo Agency / Alamy Stock Photo

The Complex Issue of Oak

The subject of the impact of wood in the wine making process was one of the first topics that really grabbed my attention.  The appeal I suppose is that the topic is both technically and chemically complex and also controversial in that people hold strong opinions on the subject.  Because it is so nuanced a topic, abbreviations do not always serve well in communicating the precise process adopted with regard to oak by any particular winemaker nor therefore what one might expect in the resulting wine. There are so many subtleties involved in its application that simply knowing a wine was aged in wood tells you almost nothing helpful.  And it is controversial because wood - especially of course when ‘new” - normally imparts flavors to a wine that some consumers find detract significantly from the natural flavors of the grape - and thus are unnecessary and indeed undesirable. The new wood serves only as “make-up”. Others find that these flavors do indeed integrate into the wine over time and benefit the wine by contributing to its aromatic complexity down the road. But even in establishing a point of view on its flavor impact, the topic is not straightforward. I, for example, find new oak flavors more “noticeable” and “overwhelming” in a Barolo than in a Burgundy.  Why would that be ? This topic deserves some inquiry.

So let us just start with some headline distinctions. Oak can be used during two different phases of a wine’s making.  

The first involves actually having the fermentation take place in an oak vessel, as opposed to stainless steel or concrete or some other substance.  For  whites, the juice flowing from pressing is simply moved (after a number of hours during which it is allowed to settle) to the wooden barrels - often quite small barrique sized - and fermentation allowed to commence. For reds, the fermentation tank will be much larger and may or may not have a lid.  Fermentation in both cases takes anywhere from seven to perhaps 21 days and the wine may remain in the vessel another week or two following the end of fermentation if it is felt desirable to maintian skin contact for longer. In practice for reds this fermentation vessel is reused year after year and so the wood is not new. After the red has finished fermenting the juice will be racked off into a different vessel and the remaining pomace may be pressed and the juice from that also included.

The second is the maturation process.  The fermented wine remains in a vessel made of some variety of wood for many months - ranging perhaps from 12 to 24. Normally that wood is made of oak but can be sourced from any one of many different forests. That wooden container may be of very different sizes and may not have been used before, or it may have seen wine from several prior vintages. Normally a wine fermented in an oak fermentation tank would subsequently also be matured in oak.

What you give up fermenting in wood is some control.  A stainless steel fermentation tank can be vary large and can be temperature controlled. The bigger the wooden fermentation vessel the less easy it is to have a cool cellar do the cooling job. Simplistically, temperature is important for fermentation since color transfer from the grapes skins requires a higher temperature than the creation of desirable volatile aromatics, which are transferred at a lower temperature. So more control affords less risk. Plus stainless steel tanks are easier to clean initially and so there is less risk of bacterial contamination during the fermentation itself. 

What proponents believe you gain by fermenting in wood is that oak flavors integrate better during the maturation process - for both reds and whites - if the fermentation itself was done in wood. This is particularly true of whites when fermented in smaller barrels. There are many reactions involved but it appears the yeasts essentially absorb some of the new oak flavors and make them less pronounced, and the yeasts may themselves coat the interior of the barrel, reducing the contact of the wine with the wood itself. The result is the counterintuitive outcome that a white wine fermented in a new oak barrel and subsequently matured in that oak barrel will taste less of new oak than one fermented in steel and then transferred to a new oak barrel.  The fermentation process itself mutes the impact of the new oak. 

Fermenting reds in a wooden vat without a lid certainly brings a lot of contact with air early on, so the yeasts can multiply more easily and of course any manual punching down of the cap or pump over is easier. Many assert wood has desirable thermal properties relating to maintaining temperature, though others say concrete is better for this purpose. The vat’s conical shape may help with extraction. Some say wood gives more aromatic precision to the wine during fermentation. Often though fermentation in wooden vats is done for reasons of tradition - the vats have always been used in the cellar and since they last a very long time there is no reason to replace them. And they really look better than adjoining square, painted concrete blocks !

The rest of this post will focus only on the second process - maturation of the wine in wood for many months. 

The reasons for doing this are several. Maturation in wood stabilizes color of a red wine because of the reaction of the tannins with anthocyanins and the tannins are softened by polymerization. The transfer of oxygen through the wood to the wine also oxydizes the wine just slightly which improves structure. 

Before we look more closely at the function of wood and how it influences the wine, a brief digression on types of wood is helpful. 

Oak is a genus called Quercus - of where there are several hundred species.  In practice we are concerned with only three - one American and two European. American oak is Quercus Alba, which is highly flavored and requires a saw to cut it if the staves to be watertight. Among the European species, of primary importance is Quercus Sessilis, and secondarily Quercus Robor.  Both these incidentally must be split along the grain and the staves will only then be watertight. If sawn they are not. So barrels made from European oak are more expensive.  Quercus Sessilis has the higher reputation since it has the tightest grain and gives attractive aromatics. It is found in forests in central and eastern France - Troncais (actually a part of Allier), Allier, Nevers and Vogues.  The forests Limousin in the south of France are of the species Quercus Robor, which has a looser grain and imparts less flavor. A new 225 liter sized barrel costs about Euro 700 - so adds the considerable sum of about Euro 3 to the cost of each bottle of wine. 

Both the degree of flavors imparted (if new) and the degree of oxygenation achieved depend on the size of the barrel. A bigger barrel involves less surface area of wood in contact with wine, which slows down oxygenation.  A 225 L barrel might give about 20 to 40 mg/L of dissolved oxygen to the wine over the course of a year. A point that is worth noting is that a bigger barrel is also made of thicker wood - in the case of 20 HL barrels considerably thinker than 225 L barrique - so that further slows down the oxygenation process.  Grain size matters. After many vintages the wood itself becomes less porous to oxygen. Though the staves may loosen just a little over time, it is fair to say older barrels transfer oxygen less efficiently. 

It is to be noted that one more and more frequently sees larger barrels being used in Burgundy than the conventional 228 L.  This is especially so for whites.  Many are using 600 L barrels to slow down the oxygenation process. Some are experimenting with Italian style botti - which might be 10 or 20 HL. This is a trend that I expect will continue.    

If one is going to use new barrels the choice of cooper is very important.  I am no expert but I am told that the understanding one develops with one’s cooper is hard to overestimate. Mistakes can be made, with disastrous outcomes. One cooper’s ‘medium toast” is another cooper’s “high toast”.  Nor does ‘high toast” mean you get more of everything - high toast will in fact leech less wood tannin into the wine. Some coopers work with wood only from particular forests. There are more variables in constructing a barrel than you can possibly imagine. It is also commonly understood among locals in Burgundy that certain coopers - particularly the frequently used Francois Freres -  have quite a recognizable signature that can be detected in the wine.  For this reason many use more than one cooper. 

The attentive consumer will be very aware that of late the amount of new oak is being reduced at many Domaines in Burgundy.   Some Domaines that historically used 100% new oak are dialing this back just a little.  Many that perhaps used 75% new oak on their Premier Crus are now using closer to 60%.  A small but noticeable trend. But it is important to remember that many of the absolute top Domaines are still unhesitatingly using 100% new oak - DRC, Domaine Leroy and the followers of Henri Jayer.  Dujac also - at least when Jacques made the wine. And although in Barolo there are some celebrated names, having in the past moved towards new wood barrique, that are reverting more towards aging the wine in larger botti, the number of producers overall using barrique still outnumbers those using botti, especially in La Morra. This is fine of course. There is room for all styles of wine.  Just don’t ask me to drink them all.

Which brings me to the all important practical questions.

Is it the case that the flavors of new oak truly integrate into the wine over time ?  Here I am talking over say a twenty year period. I myself typically age my grander wines quite a while. So whether I pick up excess new oak flavors at year five or even year ten does not really concern me. What matters is how it influences the wine at year twenty.

The proponents of the use of high proportions of new oak principally do this for one of three reasons. 

The first is purely practical and has to do with how hard it is properly to clean a used barrel - so one uses old barrels as seldom as is consistent with your view of that cleanliness issue. Certainly I have had wine from what would appear to have been ‘dirty” barrels and it is not pleasant.

The second, as mentioned above, is that new wood has better oxygenating properties than old wood. The transfer of oxygen is somewhat compromised by prior use as tartrates build up over the vintages. The gentle oxygenation gives a roundness to the wine, reduces astringency and stabilizes color. In this there is universal agreement. Older barrels therefore do not perform these functions quite as well and perhaps not well at all after six or seven passages. Some believe the oxygenation properties of new wood are so important that they must prioritize the use of new barrels and simply find ways to mitigate any unintended “new oak” flavors that result as best they can.

The final reason is that to some winemakers new wood impacts desirable flavors and qualities to the wine. And this last is surely where the real controversy lies.  It is fair to say no winemaker today making wines of terroir will say he actually wants his wine to taste of toasty new oak. He will speak in terms of the enhanced complexity over time that aging in new oak affords. Henri Jayer spoke of the favorable catalytic action of wood tannin in the staves of a new barrel with the grape tannin and other phenolics in the wine, giving in time more stable and complex flavor molecules. But these desirable benefits do seem to come only with the addition of certain unavoidable flavor overlays that the new wood necessarily imparts  - vanilla, coffee and grilled almonds. Does the asserted added complexity justify the presence of those flavors ? 

Unhelpfully, my experience is both limited and quite mixed, but if you pressed me I would say that the flavors of new oak to my taste remain present in the wine for very long periods. But it is also surely the case that Grand Crus can “handle” more new oak than Premier Crus.  It is evident that the growers believe this since none to my knowledge are putting their Premier Crus into higher proportions of new oak than their Grand Crus (except Rousseau in relation to the Clos St Jacques, which is really a Grand Cru).  The sheer depth of fruit of a Grand Cru - and perhaps its higher tannic profile - seems to have enough presence on the palate not to be overwhelmed by all that new oak. Henri Jayer used to say it is about having adequate “concentration” of fruit to support the new oak. Perhaps with the tendency toward lighter extractions, today’s fruit at the Premier Cru and “Village” level is of a nature that it is appropriate to dial back the new oak a bit.  And for sure I have no adverse reaction to a Premier Cru Burgundy that has been aged in 50% new oak.  And Burgundies aged in 100% new oak work just fine for me also, provided the vineyard has what it takes and the oak has had time to integrate into the wine over 20 years or so. In the context of Barolo, subject to the point below, I can say with more confidence that to my taste a Barolo aged in new barrique never loses that influence in its creation. Curiously, too, I notice the new oak more when drinking the second glass than the first.

Why do I find new oak so much more objectionable with Nebbiolo than I do with Pinot Noir ? Clearly Nebbiolo has plenty of natural tannin in a way that Pinot Noir does not. The grape lacks for nothing in the structure department. So perhaps the role of new oak seems more redundant in the case of nebbiolo ? The difficulty with that argument is that the pinot noirs that seem most able to ‘absorb” new wood are the Grand Crus, which normally have the highest levels of natural tannin. Cabernet Sauvignon, too, with its high level of tannin, in the main seems able to accommodate new oak when done well. So it surely cannot be the presence of tannin alone that drives the disparity of my tolerance.

More likely it is that Nebbiolo’s particular flavors are so distinctive that any overlay of vanilla from new oak is more noticeable and therefore an unwelcome intrusion. Pinots noir’s intrinsic flavors are less insistent, and those flavors seems to “work” and integrate better with any residual flavors present from the wine’s time in new oak. In particular nebbiolo’s more savory flavors in the family of liqorice or tar or balsamic do not marry well with vanilla, which adds an unwelcome sweetness to flavors that are naturally savory. I surely like vanilla sauce with some ice cream flavors but less with others.

Could it just be what one is accustomed to drinking ? It is through drinking “traditional” Barolo made in old botti that I have become more sensitive to oak flavors when they are present in any red wine.  Given that old botti - with at least ten times the volume of a standard barrique - impart no flavors of new oak at all, the Barolo I habitually drink is the equivalent of drinking completely unoaked Premier or Grand Cru Burgundy. And if that is all I did (were it even possible), I am sure I would be more sensitive to the one Burgundy that came along that had seen a good amount of new oak and find the resulting flavors an unnecessary overlay. So I experience a sensitivity and response to the presence of oak based on what I am accustomed to drinking - unoaked Barolo but Burgundy with at least some new oak. Start drinking a lot of unoaked wine - even Bordeaux - and then come back to an example aged in new oak, and I expect the oak is pretty evident. And then one is simply left with the question of whether one prefers that new oak presence or not, which is a purely subjective preference. 

The caption picture is from the new cellar at the admirable Cascina delle Rose in Barbaresco and was chosen simply to illustrate different barrels sizes.  

Stems, Crushed Grapes and Pressing

Either I did not properly pick up on some distinctions early on in my studies or people were using the terms “crush” and “press” pretty much interchangeably, so I have since had to straighten out what all this means. My confusion has arisen perhaps because in times past the machines that destemed the grapes basically could not do this without also puncturing the skins of the grapes to a significant degree. What you got was a mush of broken berries and juice. So if one was going to remove the stems one had to accept that a lot of juice would start to flow out of the berries immediately, in the case of white grapes for the short time the grapes are in the press machine itself as the pressing was taking place or in the case of red grapes in the fermentation vessel. There was in practice no option to destem and retain intact (‘whole”) berries (absent desteming by hand, which was not practical in the past but with todays higher prices a few are willing/able to do this).

Today these destemming machines are more gentle and so, given one wishes to destem, one still has the option whether or not to retain intact berries or partially crush them (puncturing the skin of the grape) subsequently. As I understand it, modern machines can remove the stems while leaving more than 80% of the berries whole. Some are even more effective in retaining whole berries. One has only to inspect Roberto Conterno’s machine to appreciate how sophisticated these instruments have become.

For White Wines. To be clear, the issue whether to destem is not as important for white grapes as it is for reds. Today, most makers of white burgundy simply toss the grape bunches into the press, stems and all. But there are some nuances here.

Since it can take perhaps four hours to perform the pressing of white grapes,  the winemaker may want to give the juice the benefit of some skin contact during this period and so partially puncture the skins at the start of the pressing by crushing the grapes - a process in France called "foulage".  Though there appears to be no universal agreement on the topic, foulage may result in a must with slightly higher total acidity. This process - crushing the grapes prior to putting them in the press - also allows the grapes to be "pressed" more quickly if that is the objective - and, importantly, at lower levels of pressure since the skins are already broken. It may also be that the few hours of skin contact during the pressing helps reduce the risk of later oxygenation if the juice, enriched by a higher level of phenolic elements, is allowed to settle a short while after the pressing. What you lose by crushing the grapes in advance is a “purity” of juice that comes from pressing whole berries.  The proponents of not crushing white berries before putting them in the press believe that crushing these grapes releases more solids from the grapes into the juice, which may make for a wine of less finesse and require management of these sediments later. Many influences factor into the decision whether or not to crush white grapes. It is my understanding that invariably in Burgundy white grapes are today not destemmed - they just go into the press stems and all. So the grape berries are presumably whole. Only exceptionally are the skins crushed before the grapes are put into the press. But the point I want to stress in this post is only that in the past that decision was taken away from the winemaker if he destemed - the grapes would be crushed by the destemer. Today they are not. So there is more choice/control today in deciding in which direction to go.

A reason for retaining the actual stems is that apparently these stalks will create channels or air pockets through which juice can easily flow. So that juice, during its passage out of the press, is in less contact with the skins of other berries than if these air channels were not to be present. Thus the extracted juice is very clean because it has had less contact with phenolic components of other grapes while in the press. This is the approach taken in Champagne.

For Red Wines. The red wine maker today similarly has the option whether or not to ferment with initially crushed or uncrushed berries in the fermentation vat.  Leaving some berries whole allows for these berries to start the fermentation process intact - a type of intercellular fermentation. This is thought to give additional aromatic complexity.  To be clear this is not full on carbonic fermentation. There is no flushing out of the oxygen from the fermentation vat. But the intact grapes release juice (and thus sugar) only when the skins break down - and this takes about two days. Intact grapes that undergo this intercellular process swell and the skins split after a couple of days. By this time there alcohol has reached only about 2%. If for some reason the skins haven’t broken down after a few days some winemakers will perform some foot treading or batonnage to break up some of the skins. Some crush some berries only and place these at the bottom of the vat. As these grapes at the bottom of the vat undergo fermentation in the presence of oxygen and yeasts work to turn the sugar to alcohol, this fermentation also produces C02, which to some extent pushes the oxygen out of the vat for the still intact grapes higher in the vat. But nobody wants too much of the “carbonic” flavor that comes from full intercellular fermentation. What you want is the added complexity. The trend in Burgundy of late has been to leave a good portion of the berries whole.  This in turn creates some difficulties in assessing the progression of fermentation since sugar is released only over time as these berries individually breakdown and release juice. Dominique Lafon has stressed this difficulty.

For completeness, full carbonic maceration involves flushing the air (and thus the oxygen) out of the fermentation vessel, then adding whole berries and sealing the vessel closed. Normally the actual stems are included, because historically this was the only way to assure the beery skins were not broken. These berries experience two or three days of intercellular fermentation than swell and the skins then break. At some time thereafter the grapes are pressed and the fermentation can be completed if necessary with the juice alone ie no longer in contact with the skins.

You can of course destem, put whole berries into the vat and then include back some or all of the stems. Jean Marie Fourrier I believe does this. Some - like Sylvain Pataille as I understand it - destem and then crush the grapes to the desired degree as a separate process. There are numerous variations.

The message in this post is that as a definitional matter the term desteming should mean simply removing the stems - without any inference whether the grape berries are to be crushed or not, which is today an entirely independent decision.  And "crushing" grapes is absolutely not the same as "pressing" grapes.  It took me too long to figure this out !

There are of course several types of presses.

I commend the podcast # 416 on Levi Dalton’s “I’ll drink to that” website by Erin Scala on the subject of desteming and a May 2020 “Zoom” Session on Jasper Morris’s website InsideBurgundy.com

The small decisions

I was in a wine store reading the back label of a bottle of Fixin 2015 from a grower with whom I am not familiar, thinking the information set out was saying all the right things consistent with high level of artisanal care and hands-ff winemaking. Perhaps I should buy some, especially since it seemed good value. But following a few minutes research at home I decided against it because the wines apparently are not especially good and certainly not of the quality you might hope for from the information set out on the back label.  This is not to single out the producer in question - especially since I haven't actually myself tried the wine - but merely to illustrate that simply describing even with some precision how the grapes are grown and the wine made evidently leaves out relevant details that must make a difference to quality. 

Of course we all know grape growing and wine making involves a series of dozens of interrelated decisions to take certain courses of action or not to do so.  But it remains surprising to me that when the headline decisions are truly the same - such as fermentation times and temperature, use of clusters and ambient yeasts, type of fermentation container, levels of extraction, timing of malolactic fermentation and so forth - two wines can vary so much in quality. Why is it the Gevrey Chambertins of Eric Rousseau are simply better, when ostensibly he makes the wine no differently than many ? I suppose it is reassuring there is no actual formula.  It is certainly true that what one might think of as the five or even ten most influential decisions in the winemaking process alone are not enough. 

Quoting from the Rare Wine Company site in relation to Bruno Giacosa, Bruno had told Gerald Asher in the early 1990s -  ”Winemaking involves a great many small decisions, each affecting the next. One can only hope to get them right, to capture what there was in the grapes to begin with”. It seems winemakers, quite understandably, are perhaps not always willing to divulge to the casual visitor every decision nor the underlying elements that go into making it.  Some of this is surely real talent - pure intuition in response to a particular set of circumstances, not necessarily replicable with the same results on a second occasion. Experience definitely counts too in assessing the benefits and risks of every little decision.  Some just have the magic.