Another wild yeast question

Oswaldo's post reminded me of something that's been on my mind for a while now. At one time, it seems the prevailing wisdom among winemakers (in California, anyway) was that inoculating your must with a chosen yeast was safer than letting wild yeasts do the job. Just letting any old yeast in with the grapes could results in off-flavors and such. My question is, how often does this happen? If this is true, then one would expect that with greater use of wild yeast fermentation we'd see some winemakers having to toss at least some juice down the drain due to yucky yeast issues.

Anyone know if this is in fact, true, or if the old "prevailing wisdom" was overblown?

One of the California wine labs (The Wine Lab? - Vinquiry?) did a study a number of years ago and discovered in almost every case, so-called "wild yeasts fermentations" were actually commercial yeast fermentations. The source of the commercial yeast was said to be resident populations in the wine cellar. The reason commercial yeasts were developed was precisely for the reason(s) you mention. Wild yeasts were unreliable and often produced substandard or undrinkable wine.

Chiming in...

I can't tell you how many times my CA winemaker friends would shudder at the mention of wild yeast fermentation.

There was usually very little trouble getting the must to start fermenting on the wild yeasts. That wasn't the problem.

The problem was the wild yeasts usually weren't sufficient for totally fermenting out the must into a high enough level of alcohol to make real wine. Or good wine, anyway.

If you're making it for yourself, or if you're a 'gentleman farmer' who doesn't really care about things like profit, or cash flow, or other such mundane issues, then wild yeasts might sound terribly, terribly romantic. But if you're serious about making a consistent quality product with your sense of style (and don't kid yourself, even those winemakers who humbly tell you they "just let the grape express itself" have sizable egos), and don't have unlimited sources of wealth, wild yeasts simply aren't practicable or desired.

Hoke,

Many French producers, especially organic and biodynamic, claim to be using wild yeasts. I wonder what this means in practice when it comes to managing fermentations because the best of them are making excellent wine.

I would like to probe this and need to look at the tasting agenda for the next few weeks to see whether any producers of this kind will be exhibiting here. Olivier Humbrecht would be ideal but he's not on the agenda.

Are there any good questions which I should ask to avoid being drowned in generalisations?

The producers I've talked to are more concerned about the fermentation sticking than anything else. This would be a particular problem for the many producers here who choose to pick at very elevated Brix levels, even if they're going to add some water before fermentation I believe you're often well north of 15%.

Tim:

Personally, I'd be interested in asking how they maintain consistency with wild yeasts.

Not only alcohol levels (although that would definitely interest me), but also consistency of taste, aromatic expression, etc. Few winemakers I know would be willing to give up the ability to control what they are producing, quite frankly. For them, not knowing what your target is, or not knowing what you're going to end up with every time you make a wine would be a horrible thought. (And yes, I know I'm being influenced by the squeaky cleans from places like UC Davis as most of my models. )

I'd also be interested in knowing if they intentionally create or foster conditions that create a strong ambient yeast culture in their fermentation area? Which, to me, might blur the line somewhat between "wild yeast" and "cultured yeast". Or to say it another way, you can 'culture' yeast without actually doing it in a lab, albeit in a rather crude sense.

Now if the phrase "ambient yeast" were used, I might not be so leery of the claims.

The only way I'd buy claims of wild yeast fermentation from most producers, and especially those with identifiably styled and large scale production, is if they had a concerted program to develop the surroundings into a 'yeast rich' environment.

Please understand me here: I'm not saying that people don't do wild yeast fermentation, Not at all. I've had several of them over the years. I simply question the viability of a wine brand that relies on a given identity or style being successful at wild yeast fermentation on a large enough scale to impact the market. If you're looking at a 'one off', or an oddity that is produced and released only when it's successful or approved, then that's another thing altogether.

Also, I'm just suspicious of some claims...case in point is an instance where I was told in all seriousness that a winemaker used wild yeast fermentation (and no, no names from me; you'll have to trust me on this). Then I discovered that the yeasts were indeed, at one time, wild, but had been carefully nurtured in a lab. The winemaker claimed he was using the "wild yeasts", when he was actually culturing the ambient yeasts...to him, it was the same thing, since he was "using what nature gave him instead of importing foreign yeasts." [If his wine had been in any way decent and drinkable it would have been worth a discussion; as it is, the wine wasn't worth the time or verbiage.]

Again, small batch, one off, artisanal wines are fine and dandy, and I'm all for wild yeast experimentation...heck, I'm all for any and all experimentation because that's how we learn things...but as an economic model, I'm leery.

Thanks, everyone. I can see the concern over stuck fermentations, particularly here in California. Shouldn't be a problem if the "wild yeast" is indeed actually commercial yeast that's established itself in the cellar, but one generally doesn't want to take chances with one's livelihood.

I guess the question would then be whether those using wild yeast end up struggling with their fermentations more than others.

Tim:

Personally, I'd be interested in asking how they maintain consistency with wild yeasts.

Not only alcohol levels (although that would definitely interest me), but also consistency of taste, aromatic expression, etc. Few winemakers I know would be willing to give up the ability to control what they are producing, quite frankly. For them, not knowing what your target is, or not knowing what you're going to end up with every time you make a wine would be a horrible thought. (And yes, I know I'm being influenced by the squeaky cleans from places like UC Davis as most of my models. )

Hoke,
I'd be willing to wager that most of the vignerons you either visited or passed by recently in the N Rhone use ambient (finessing the question of what is wild these days) yeasts for fermentation. Certainly, I'd guess that Chave, Clape, Gonon, Allemand, Faury and Faurie do, and one only has to look at their output to judge whether they're consistent. Of course, too much consistency ain't necessarily an asset, either... unless you're Clos du Bois or Kendall-Jackson. Most of those vignerons I've mentioned operate out of cellars in which wine has been made a long time, so there's almost certainly an established yeast population, and one which has undergone a selection massale of sorts over the decades. I'd be far more leery about using ambient yeasts if I were operating out of a brand-new facility in Napa.

Again, small batch, one off, artisanal wines are fine and dandy, and I'm all for wild yeast experimentation...heck, I'm all for any and all experimentation because that's how we learn things...but as an economic model, I'm leery.

Perhaps all those folks I've mentioned constitute "artisanal" producers and so can be dismissed as not operating on the scale you're thinking of. Dunno.

Mark Lipton

Question for Alan (or anyone else);
What condition or at what stage of growth would the colony of Saccharomyces or “resident” yeast be at in a clean and sanitized winery?

Very likely once grapes were brought into the winery area the “resident” yeast will get “excited”. This is why I said in Oswaldo’s original post that most likely the prepared must or juice in a winery would very likely have a small population of Saccharomyces yeast. But the so called “native” or “wild” yeast present on the grapes themselves will have a “jump” on the “resident” yeast and dominate the early stages of fermentation if nothing was done to inhibit them from doing so.
By returning the pomace year after year back into the vineyard as compost eventually I think that a “wine yeast” strain will eventually dominate the vineyard.

Salute

Personally, I'd be interested in asking how they maintain consistency with wild yeasts.

I think that French artisan producers are much more prepared to live with marked vintage difference effects than is perhaps the case in California. For the European consumer of that type of wine vintage differences also add to the charm. Zind-Humbrecht is again an interesting case; even the degree of sweetness from the same vines can vary a lot from year to year; this is less easy for the customer to live with, but at least Z-H tries to help with sweetness/dryness "indice" numbers.

Clearly they don't want to their wines to fall below the house quality level (hence the best declassify in poor vintages), but differences of character and taste are acceptable, even welcome.

Tim:

Personally, I'd be interested in asking how they maintain consistency with wild yeasts.

Not only alcohol levels (although that would definitely interest me), but also consistency of taste, aromatic expression, etc. Few winemakers I know would be willing to give up the ability to control what they are producing, quite frankly. For them, not knowing what your target is, or not knowing what you're going to end up with every time you make a wine would be a horrible thought. (And yes, I know I'm being influenced by the squeaky cleans from places like UC Davis as most of my models. )

Hoke,
I'd be willing to wager that most of the vignerons you either visited or passed by recently in the N Rhone use ambient (finessing the question of what is wild these days) yeasts for fermentation. Certainly, I'd guess that Chave, Clape, Gonon, Allemand, Faury and Faurie do, and one only has to look at their output to judge whether they're consistent. Of course, too much consistency ain't necessarily an asset, either... unless you're Clos du Bois or Kendall-Jackson. Most of those vignerons I've mentioned operate out of cellars in which wine has been made a long time, so there's almost certainly an established yeast population, and one which has undergone a selection massale of sorts over the decades. I'd be far more leery about using ambient yeasts if I were operating out of a brand-new facility in Napa.

Again, small batch, one off, artisanal wines are fine and dandy, and I'm all for wild yeast experimentation...heck, I'm all for any and all experimentation because that's how we learn things...but as an economic model, I'm leery.

Perhaps all those folks I've mentioned constitute "artisanal" producers and so can be dismissed as not operating on the scale you're thinking of. Dunno.

Mark Lipton

As usual, you've cut through my verbosity and gotten close to my point: that's my concern too. Difference in my mind between the old, ancient cellars permeated with who knows what and a stainless steel palace washed with bleach every day.

Also what you mentioned about the actual definitions of "wild" and "cultured". Hence use of the term "ambient".

Victorwine - You will have to find someone more knowledgeable about yeast than me to answer your question, sorry. I do know that no matter how hard one tries, every wine cellar builds a library of yeasts, molds and other bacteria over time. Even the most fastidious of cellar masters have this problem. It's probably fair to say that the only cellar without resident yeasts/mold/bacteria is a new one that has never been used for fermentation.

Ambient seems like a better word than wild because, if the ambition is to reflect terroir, you're still doing it if you cultivate your own native yeasts. I would bet that's what French natural winemakers do, because they have families to feed and it would be too much risk to just let nature take its course the truly "wild" way. As Hoke mentions, they still see that as wild because it's ideologically as "true to the land" as using actual wild. The fundamental point is to not buy any outside yeasts, even neutral ones.

Ambient seems like a better word than wild because, if the ambition is to reflect terroir, you're still doing it if you cultivate your own native yeasts. I would bet that's what French natural winemakers do, because they have families to feed and it would be too much risk to just let nature take its course the truly "wild" way. As Hoke mentions, they still see that as wild because it's ideologically as "true to the land" as using actual wild. The fundamental point is to not buy any outside yeasts, even neutral ones.

Most of the cellars I've seen in French wine districts have dirt floors and a lot of spitting of barrel samples takes place on those floors. After a century or two of those practices, I'd imagine that the cellar harbors a pretty vibrant yeast population, but one which has been selected (intentionally or otherwise) for salutary performance in fermentation. It also helps explain those appealing notes of Brett in so many of my favorite French wines, too.

Mark Lipton

thought I'd post a relevant TN of a recently tasted CA chard...

2008 Broadside Chardonnay Wild Ferment (Edna Valley) Blissfully oak-free, unfiltered, native yeast chardonnay. Nose is very, very leesy and deep with cling fruit, apple, and a bit of almond. Beautiful aromas, really. First tastes (which was a bit cold at fridge temp) was like a flavorful but flat, quality Champagne. That leesy character carries into the flavor, lots of apple, very rich mouthfeel. Not soft by any means but I think it was a bit short on acid for my tastes. The acidity level actually went very well with a potato frittata and salad with white balsamic dijon dressing so I'm not complaining but on its own it was just average on the finish. There is some minerality and good balance. As it warmed the depth grew across the board. Overall, I'm happy for the $15 and would get it again. Joint project by Chris Brockway (Broc Cellars) and Brian Terrizzi (Giornata Wines).

Thanks Alan, agree with everything you said. The idea of having viable or even a slow reproducing colony of yeast or bacteria lurking about or even in your must or juice isn’t really a “problem” until that colony reaches a critical mass for a given volume of juice or must. Just observe what occurs on the grape berries themselves on the vines. The grape microbial flora is dependent on many factors such as rainfall, humidity, vineyard spray regimes, vineyard altitude, insect vectors, nitrogen fertilizer regimes, and winery waste disposal practices. Take rots for instance, if you notice the start of Black Rot or Grey Rot (activity of certain species of molds) you spray the vines to eliminate it or try to keep it in check or at bay. Under certain conditions members of the genus Botrytus (Noble Rot) can be found, now for certain wines this may be considered “desirable”. So instead of trying to eliminate it or keep it in check you might actually encourage it.

Salute

Relatively recent research I've seen shows the following:
*Grape surfaces do not show anywhere near the diversity of yeast strains that winery surfaces or equipment do.
*The yeasts involved in fermentation are almost always (though I wouldn't say always) likely to be those resident on winery surfaces or equipment - the evidence shows they do NOT come from the vineyard (at least most of the time).
*Wineries that have never inoculated with cultured strains do not have the same yeast strain, or indeed the same strains, dominating fermentation consistently year after year. So it appears a consistent dominant "ambient" strain is not the reality in practice.
*Wineries that have inoculated with cultured strains in the past appear to have (at least one of those) cultured strains dominate fermentation consistently, year after year.

Just letting any old yeast in with the grapes could results in off-flavors and such. My question is, how often does this happen? If this is true, then one would expect that with greater use of wild yeast fermentation we'd see some winemakers having to toss at least some juice down the drain due to yucky yeast issues.

Anyone know if this is in fact, true, or if the old "prevailing wisdom" was overblown?

I think there is more fear than is warranted. Aside from the issues of stuck fermentations previously mentioned, off-flavours from "indigenous" yeast fermentations can be a real problem (e.g., high ethyl acetate production is a serious concern). Though it would perhaps be more appropriate to say that the desired stylistic goals (including aromatic and flavour goals) aren't always met with "indigenous" yeast fermentations.

Question for Alan (or anyone else);
What condition or at what stage of growth would the colony of Saccharomyces or “resident” yeast be at in a clean and sanitized winery?

They would still need to build up a significant population before casuing active fermentation; that's another (potential) reason why "indigenous/wild/ambient" fermentations have more significant non-Saccharomyces yeast involvement.

Ben
http://www.brsquared.org/wine