Commercial yeast. Do they make our wine worse?

Winemaking Talk - Winemaking Forum

Help Support Winemaking Talk - Winemaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
commercial yeast had to come from somewhere. t is the chicken and the egg issue. some of the yeast we use today all came fro a natural fermentation at one time. so what is commercial and what is natural. I am a firm believer that proponents of a natural fermentation are actually experiencing fermentation from yeast living on their premises and that these yeast are those that they used in the past. Is there really a natural fermentation?
 
Most of us don't have the luxury of living in an area where grapes are grown and wine has been made for centuries. In these places native yeasts have adapted and centuries of depositing lees back out onto the land have created local cultures. Without that it is really a crapshoot on what you can expect to be around you in the environment to ferment your wine. I'll take those "commercial" yeasts that have come from those indigenous places.
 
Two quick and dirty thoughts from someone who makes meads and country wines so have your pinch of salt ready...
1. Indigenous yeasts can still be cultured in ways that shape their activity. If I grow a culture of yeast from some raw honey and harvest the yeast after fermenting at specific temperatures and and at specific gravities and at specific pH's then I am "cultivating" those yeast cells in ways that best suit my meadery. After a couple of generations the cells I will have will doubtless be from the same strain as I started (perhaps..) but they will be more likely to prefer the conditions that I offer them than cells at random from the first generation would prefer. The environment would be selecting those best suited...

2. and implied from 1. You are not simply using (though you could) "found" yeast cells. There is a real crapshoot in that. The flavors indigenous yeast might enhance, disguise and transform may be flavors that you dis-prefer and the yeast itself may have a tolerance for only half the ABV you are seeking. Having found potentially desirable yeast cells you cultivate the attributes you prefer. That is different from lab cultured yeast because these cells best match your specific conditions and not "conditions in general"...
 
I find this an interesting subject. Mainly because two professionals I really respect do native fermentation’s. One is in Napa and the other, Two, is on the next creek over from me.

I always thought what salcoco said was the case, and it just makes sense. However, one, in Napa has had testing done and while “commercial” strains appear, there are many others, some not even Saccharomyces. He only does native.

Two blends portions of native fermentations with inoculated for their final wines.

Both cite more complexity as the reason. That is consistent with the practice of co-innoculating or sequential inoculation with various yeast strains, some non-Saccharomyces as well. There are also some combined yeast mixtures hitting the market these days.

A third, Washington winemaker, lets his crushed fruit, red, sit uninnoculated for a week or more before pitching. It is cool, but not cold where he does this so not a true cold soak. Something starts fermentation as there are bubbles. A native yeast or just last year’s bugs?

An interesting note is I read a study of grapes in the vineyard and in the winery and they found the yeast from the vineyard rarely survived the trip to the winery, I think it was like a day in the study.

I do recognize risks-what if your native species stinks, figuratively or literally? After all, commercial strains have been isolated for a reason. Stuck fermentation is of course a risk depending on alcohol level. So I’ve been chicken and inoculated.

I may try it next year on part of a crop. I keep trying to sort out the process. I don’t think I should use the same punchdowns tool, but is it a fair trial to have two ferment-one native one inoculated, in the same room?

Yes, it is cold and dark outside and I’m disciplining myself to not fiddle, so instead I ponder.
 
My two cents on all of this is the following: Yeast is yeast regarding Saccharomyces. It is debatable that the different yeast characteristics remain after aging. I like to do natural ferments because I am of the opinion that it adds to flavor profile. But not because of the yeast. In a natural fermentation, where sulfates are not added up front one will at least initially have a variety of other creatures active in the must. Depending on the fruit quality non desirables can take over and predominate. Acetobacter for instance. I harvested a record amount of elderberries this year, and looking back I think a certain percentage of the fruit was damaged by Drosophila and birds. I pitched the fruit and added honey to bring up the O.G. and left it be at room temp. After three days there was plenty of activity but no yeast smell. But a acetone smell. I quickly added Kv1116 at 1.065 and let it ferment from there. At this point it definitely has unusual and complex flavors. How it will end up only time will tell. On this batch I should probably have cast yeast the first day. So natural ferments can be done two ways. One where you cultivate the yeasts growing on your grapes and cast your starter early on. The other way is to set up your fermentation w/o intervention and see what happens. Both methods will probably give different flavor profiles. In wine making lore there is much talk about wild yeasts having fabled ability to quit at 6% etc. I believe its fable. If these yeasts existed, in certain circles one could make small fortunes selling low alcohol yeast. In the common 11-12% range for wine I sincerely am convinced that all Saccharomyces will dry out essentially the same.
 
commercial yeast had to come from somewhere. t is the chicken and the egg issue.

Many commercial yeast strains are selectively bread from parental strains to provide certain beneficial traits in wine making. But do they loose something else in that breeding process?

A good "macro" example is the VF-145 tomato, which took decades to develop but was the first tomato that was tough enough that it could be harvested with machines. But its machine harvesting traits were the primary focus and other traits like, flavor, suffered. Today's super market tomatoes are based on this breading program and I personally had no idea how good a "real" tomato could taste until I had an heirloom garden grown one. So it is not so much a chicken an egg issue as what are we loosing in traits like flavor when we win in commercial agriculture with selective breeding.

Side note: Not raging on commercial ag. One could argue that even a rather bland inexpensive commercial tomato in your daily salad is better than a really good tasting but expensive tomato that you have maybe once a month. It is a trade off. But maybe both options have a place on the market.
 
I like to do natural ferments because I am of the opinion that it adds to flavor profile. But not because of the yeast. In a natural fermentation, where sulfates are not added up front one will at least initially have a variety of other creatures active in the must.

This is a really good point.

I have tried natural fermentation. Was underwhelmed. But that may because I was doing things wrong, so was my fault, not the "natural" process itself.

But I have wondered about a hybrid approach. No sulfite to affect the native micro-biotic flora and fauna, but still pitch a commercial yeast to get some of its traits as well. Have not tried this. But have thought about it.
 
But I have wondered about a hybrid approach. No sulfite to affect the native micro-biotic flora and fauna, but still pitch a commercial yeast to get some of its traits as well. Have not tried this. But have thought about it.

This has been my practice for the last 4-5 years. I harvest my own grapes, so they are clean and we don’t pick damaged clusters. I don’t sulphate until after fermentation is complete, or mlf when I do that. I let my reds soak for a few days, until I see any action, then pitch, so any native critters are presumably overwhelmed by the pitched yeast. Mike, winemaker 3 in my ramble above, lets the natives go for several days to weeks. So far, I’ve been chicken to do that without an argon blanket.

Can’t say not sulphiting has improved things, my wine is getting better, but so is the fruit and my practices. So, might not change the flavor profile, but it reduces sulphites, at least early on.
 
Yeast strains are like dog breeds. Many, many, many strains that have specific desirable characteristics for particular purposes. The S. cerivesiae species encompasses everything commercially from bread yeast to beer yeast to wine yeast and, yes, many wild strains.

Would you dose your Cab Sauv with a jar of fleischman's bread yeast? While it may add character, I doubt it would make a better wine, aside from it probably sticking the fermentation with an undesirable level of residual sugar.

Don't treat commercial yeasts like the watery tasteless eggs you get in the grocery store while thinking the "wild" yeasts are like flavorful farm-fresh eggs.

Many winemakers seem to have a romanticized viewpoint that a "natural" fermentation will make for a better wine or that perhaps they will uncover a henchforth superior strain of yeast hiding inside their shoe. Gives me the same kind of head-slap I get from people at farmers markets asking if the wine is from GMO grapes.

Lallemand and Scott Labs have put loads of effort producing commercial yeasts from around the world by isolating them from active fermentations in wine-growing areas using natural fermentation. You can find a yeast (that is marketed) for just about any scenario.

That doesn't mean there aren't more strains out there that will make fantastic wine but there are certainly loads of strains that will make terrible wine. If undosed fermentation (aka "wild") works for you, go for it. For much of the country that is not heavily into grape-growing though, that is Russian roulette.
 
My first and currently only experience with all grape wine is I purchased my grapes from a local winery. They asked me if I would like them crushed and processed. It was 176 lbs and being lazy I accepted their offer. They added tannin, Opti Red, and Ferm O, no sulfites. I divided the batch into four equal buckets and added 4 different yeasts a few days later and noticed some activity prior to pitching. Whether it was good fruit or good luck or both, only 6 weeks after pressing I can tell this is going to be my best wine. I too though am a little timid about using only wild yeasts.
 
My first and currently only experience with all grape wine is I purchased my grapes from a local winery. They asked me if I would like them crushed and processed. It was 176 lbs and being lazy I accepted their offer. They added tannin, Opti Red, and Ferm O, no sulfites. I divided the batch into four equal buckets and added 4 different yeasts a few days later and noticed some activity prior to pitching. Whether it was good fruit or good luck or both, only 6 weeks after pressing I can tell this is going to be my best wine. I too though am a little timid about using only wild yeasts.

Wow, they really hooked you up. A little Lallzyme is all you needed (if that). Mind if ask what they charged? This was for Norton, right?
 
Many winemakers seem to have a romanticized viewpoint that a "natural" fermentation will make for a better wine or that perhaps they will uncover a henchforth superior strain of yeast hiding inside their shoe. Gives me the same kind of head-slap I get from people at farmers markets asking if the wine is from GMO grapes.

Lallemand and Scott Labs have put loads of effort producing commercial yeasts from around the world by isolating them from active fermentations in wine-growing areas using natural fermentation. You can find a yeast (that is marketed) for just about any scenario.

That doesn't mean there aren't more strains out there that will make fantastic wine but there are certainly loads of strains that will make terrible wine. If undosed fermentation (aka "wild") works for you, go for it. For much of the country that is not heavily into grape-growing though, that is Russian roulette.

I think that Masbustelo more made the point I was trying to make. That while focusing on the yeast, and stunning or killing off all the other microbiotic contributers, what are we doing to the final product? Saying that these other "critters" can cause problems is true, but is that more a deficiency of a modern wine maker for depending too much on the chemistry (i.e. SO2) to get us a product, rather than trying to find the "artful" balance of knowing the ancient trade of how to work with all the complex microbiology so they don't cause problems, but rather enhance the final product? That is: is the science of wine making killing off the art of wine making. And is the wine better or worse for that?

I don't know. I am not convinced yet either way. But I find this a very interesting question. I am thinking about it. But I am leaning more toward the art, than the science (even if I do have two university degrees in science -- but those are both in Biology -- so maybe I am biased toward a better life through biology rather than a better life through chemistry ;)).
 
Last edited:
Balaton If you think about it, there appears to be two ways to make wine. One would be with modern chemicals upfront to stun or eliminate all bio creatures and then cast yeast to do all the fermentation and transformational work. The second would be to not add chemicals upfront and either let the naturally occurring bio mass do its thing or leave the bio mass intact and augment it with cultured yeast at some point in the fermentation process. These are two very different processes and one would suspect would lead to very different profiles, I think blind testing with groups would need to be done to see if differences can be detected. And then also it would need to be determined somehow which produces the best wine (or commercially valuable). Then the blind tests would have to be duplicated at 1,2, 3 years etc.
 
Back
Top