Yeasts are used to manipulate flavour; myth or reality?

During the recent thread on acidulation, I got taken to task by Hoke for using the word "synthetic" (rightly, "commercial" would have been better) and also for quoting Nicolas Joly on the reality of such manipulation. I was intending to raise this in a separate thread and, as luck would have it, Jancis Robinson has raised this issue in today's Financial Times and, of course, exposes it much better than I can.

Here is the link - http://www.ft.com/cms/s/0/07702378-85dd ... fd18c.html

Tim,
Interesting article. I really don't know enuf about winemaking to have an opinion on your question, but will be very interested in responses from others much more knowledgeable on the subject.

During the recent thread on acidulation, I got taken to task by Hoke for using the word "synthetic" (rightly, "commercial" would have been better) and also for quoting Nicolas Joly on the reality of such manipulation. I was intending to raise this in a separate thread and, as luck would have it, Jancis Robinson has raised this issue in today's Financial Times and, of course, exposes it much better than I can.

Here is the link - http://www.ft.com/cms/s/0/07702378-85dd ... fd18c.html

This would explain the growing number of wines I have tasted over the past two or three years, while the fashion for leaner Chardonnays has been growing that say Chardonnay on the label but taste eerily like aromatic, crisp Sauvignon Blanc.

To this point I'd say, consider it a flaw and tell the consumer.

I strongly suspect that the widespread use of a relatively narrow range of commercial yeasts has accentuated this phenomenon.

To this point I'd say--speculation, given away by the words, "I strongly suspect."

Makes me wonder what she and others might think of the bread they eat, which I am sure a long time ago tasted differently than today, when yeast was wild and not commercialized.

Hi Tim,
For yeast to enhance certain or “desirable” characteristics the grapes themselves have to posses certain precursors, and the wine has to be fermented in such a way as to enhance these characteristics. It’s the quality of the grapes on the crush pad that will (or should help the winemaker) determine what style of wine is to be produced, what yeast strain will be used, and how the wine is to be handled in the cellar. Does using the same cultured yeast strain for my separate batches of Zin and Barbera make the Zin and Barbera taste exactly the same? IMHO, I don’t think so.

Salute

Makes me wonder what she and others might think of the bread they eat, which I am sure a long time ago tasted differently than today, when yeast was wild and not commercialized.

That's an interesting point. Most commercial bread nowadays is quite boring and the worst I know is in the UK. When Germaine makes bread at home, it is a lot tastier but, of course, she is using commercial yeast.

I don't know whether there are any artisan bakers out there who use wild yeasts. Doing a five minute Google in English and French, I did not come up with anything.

I would be keen to taste the results. However, the contribution of the yeasts could only be determined by tasting alongside it a loaf with an identical recipe except for the yeasts.

Does using the same cultured yeast strain for my separate batches of Zin and Barbera make the Zin and Barbera taste exactly the same? IMHO, I don’t think so.

Salute

I don't think that Jancis is suggesting that using the same cultured yeast will make two different varietal wines identical. The question is whether they might or not be more different if their own wild yeasts were used.

For the first 20 or so years of my home winemaking I used only two strains of commercial yeast - Montrachet and Pasteur Champagne, which, ironically, is not the best strain for making bubblies. I also made a few wines using the natural yeasts, including carbonic maceration (think Beaujolais Nouveau). Then for a few years I used EC-1118 exclusively. For the past few years I've used a few different strains, such as BM-45 and GRE. One of the things not mentioned in the article is that many of these newer strains require the addition of yeast nutrients. Without these additions the yeast can stop fermenting or generate H2S, the rotten egg small, which can then generate mercaptans, which also smell terrible. While I've been using some of these newer strains, I've generally been quite pleased with the results and I think my recent wines are better than wines I've made in the past. However, I always cringe when I have to add any chemicals (except K-meta). I've read the Lallemand catalog and they claim that many of the strains, with the addition of the yeast nutrients, do things like reduce malo-lactic acid, or make compounds that enhance mouthfeel or aromatics. It's all very complicated and I am one who prefers simplicity.

Tim
Yes, supermerket bread here is generally an abomination and not always just the pre-sliced plastic wrapped sort. There are a few artisan bakers out there - indeed until 2-3 years ago our little village had one of them.

I've taken to home baking bread in recent times, and in an ordinary oven not a bread-maker. Not all the time, maybe one loaf in three that we eat. I do use commercial packet yeast and I'm tempted off the back of this to look into trying other yeasts out. Luckily we have an old (water) mill about 30 miles away, that's been restored back to full (and commercial wroking order). We've been very impressed with their spelt flour, but there's a decent range to choose from.

It's also been interesting to see that without preservatives, my bread lasts maybe 4-5 days before it starts to go off. I suspect commercial loaves must do at least twice this time when transport etc. is taken into account.

n.b. I'm certainly no Celia and wouldn't win any prizes for my bread, but it's good to do it every now and again.

regards

Ian

We have used different yeasts on the same lot of wine. In 2005, we used three different yeasts on one lot of viognier, D2, Epernay, and one barrel of native yeast. There were obvious differences while the wine was fermenting and immediately after fermenation. With some time in oak (neutral oak only) those qualities faded as the exotic fruit recovered and grew in strength. We blended the lots before bottling, of course, so did not have the opportunity to study that further. Every year we choose different yeasts for our various reds, but seldom do a side-by-side comparison. The effect of the yeast is most apparent when the wine is young, and it fades with even 6 months bottle age. The effect of the yeast is due to its conversion properties--does it run hot or cold, slow or fast, its nutrient requirements, etc. Depending on its performance a yeast may enhance floral properties (even in reds) color, pepper, or tannin.

Soapbox moment: Please correct your friends if they say . . . .
'Yeasts add flavor." They do not, any more than bread yeasts flavor your bread.
"Yeasts are synthetic." They are alive and natural, simply bred in a clean environment and separated by type, just like city folk. Who last I checked are not "synthetic."

Like many observers of the wine scene I have been dimly aware of how the wines of the world are starting to taste much more similar, despite the fact that they come from a wider range of geographical sources than ever before. I strongly suspect that the widespread use of a relatively narrow range of commercial yeasts has accentuated this phenomenon.

I am disappointed that Robinson would say something like this, and is apparently earnest. It is complete and utter flapdoodle and unworthy pot-stirring, very disappointing journalism. There are more yeasts and combinations of yeast available than ever before. You can even pre-mix your yeasts if you're into the mad scientist thing, you don't have to keep them separate in each lot. If critics are tasting a narrow range of wines, my theory is that it's because they have ceased exploring the world and expect it to come to them. Producers and marketing agents study critics and their tastes and design or select wines for each critic based on their anticipated response. Sure, all the major critics annually visit a gallery of producers but in the New World, that 'Christmas card list' as it's called is chosen from samples which have already been reviewed and received high scores. So the critics themselves are creating a maelstrom of devolving type . . . they select their stylistic favorites from a narrowed gene pool, encouraging even more narrowing of their submission base. Only noobs in the industry send their wines out to everyone for judging or critique. Anyone with experience and marketing savvy carefully chooses their house critics.

Soapbox moment: Please correct your friends if they say . . . .
'Yeasts add flavor." They do not, any more than bread yeasts flavor your bread.
"Yeasts are synthetic." They are alive and natural, simply bred in a clean environment and separated by type, just like city folk. Who last I checked are not "synthetic."

Oh, we pretty clearly established that in the separate preceding thread that Tim referenced, Mary.

Tim immediately said that synthetic was a poor---and incorrect---choice of word, and replaced it with "commercial" yeasts. [Better, but still not correct.]

And thank you for an excellent exposition of the topic in your post, Mary. Well done.

Ah, I hadn't read that thread, but I see that you addressed the point thoroughly!

There's no such thing as 'synthetic yeasts'. Yeasts are natural organisms.

Yeasts occur naturally, and yes, should you allow natural yeasts in the air to come in contact, naturally, with grape sugar, you will get fermentation as a result.

Trouble is, it is not reliable, controlled, or consistent fermentation. We could, in our vineyards, allow that to happen: however, the yeast present in the vineyards/air is sufficient to begin fermentation, but is not sufficient to complete fermentation. So we use yeasts that are cultured.

Some cultured yeasts are developed to do certain things. Some wineries like to experiment with different yeasts to get different results. Sometimes they get positive results; sometimes they get negative results. Usually, they settle down with certain strains or cultures they become familiar and comfortable with.

None of the yeasts I am aware of are particularly evil, or even mischievous. They are all perfectly nice, well-behaved, and essentially good-intentioned. They just want to do their job in life, which is to ingest sugar and excrete alcohol, fart some carbon dioxide, and generate a little biological heat. Then die.

And every single winemaker I know considers yeasts as part of the fermentation process, and looks for the best possible yeast they can find to do the job they want/need done.

However, in future, I will be very careful when I pass by the package of baker's yeasts I have in my kitchen. Never know when the little critters will turn on you.

I wasn't meaning to address Tim directly with my comments. It's just that, as you know, it's become trendy in wine circles to bash yeast and technology and even oak, and there's a growing surge of misinformation out there. Brown belts--they know just enough to be dangerous to themselves and others.

Brown belts--they know just enough to be dangerous to themselves and others.

Ha - I like that expression!

It's just that, as you know, it's become trendy in wine circles to bash yeast and technology and even oak, and there's a growing surge of misinformation out there. Brown belts--they know just enough to be dangerous to themselves and others.

Hold on, Mary. Are you denying that technology can be abused and, more specifically, that some of the claims made for yeasts, including by Lallemand, are untrue?

There are certainly a lot of wines out there that are over-oaked for my palate, which is something on which black belt is not necessary to express an opinion.

Tim York: Hold on, Mary. Are you denying that technology can be abused and, more specifically, that some of the claims made for yeasts, including by Lallemand, are untrue?

Technology can be abused. So can a lack of technology. There are a number of lazy producers who profess a philosophy of minimalism, and whose wines are filled with VA, brett, unfermented sugars and/or unnecessary sediment. I am not a fan of squeaky-clean wines btw, but both sides of that argument have their extreme examples, don't they?

I'm not sure which claims you're referring to and don't have time to read the Lallemand catalog and guess--but I'd be happy to take a poke at answering your question. Could you quote some examples of what you're referring to?

I guess it's time to weigh in, and I do apologize in advance if my emanations are not 100% clear: this is due to my less than perfect command of the English language (which is not my mother tongue).

First, there is quite a common misunderstanding about what yeasts can do — and what they cannot do. Aromas in wine, chemically spoken, are terpenes, and yeasts definitely cannot create terpenes, period.

What can happen, especially in modern white wine-making, is that short-lived aromas (not terpenes, but don't ask me what they are chemically) arise from low-temperature, cool fermentation: aromas that frequently are described as sauvignonesque, candy-ish, bubble-gum-ish. As has been said: Wait half a year, and then you have what the wine-maker has intended — and what the aromas in the grapes are able to give.

Thus said, there are yeasts that are able to create short-lived (up to a few months) aromas on an enzymatic basis. These yeasts — at least here in Austria, but I guess that's the same around the world — are recommended for wines of the Nouveau/Novello type: bottled right in the year of harvest, marketed extremely early and meant to be drunk within 6 to 9 months after the harvest. But, as a sales representative told me: "It would be absolutely crazy to use this type of yeast for classic wines that are intended to age, and I know nobody who does." This is mirrored by a statement of Gerhard Wohlmuth, one of the top producers in Southern Styria: "The wines we are recognized for, nationally and internationally, were certainly not fermented with the yeast we use for 'Junker'." "Junker" (dictionary says "donzel, nobleman") is a brand name for very basic Styrian whites released as early as late October: Styria's answer to Beaujolais Nouveau.

It's a pity that serious journalists — and I do admire Jancis Robinson, finding her one of the most serious around — sometimes are not aware about simple scientific facts.

Thank you for listening.

It's a pity that serious journalists — and I do admire Jancis Robinson, finding her one of the most serious around — sometimes are not aware about simple scientific facts.

Thank you for listening.

It's one of the reasons that make me react negatively to wine critics who have no-to-minimal technical training. It would be much nicer to say nothing rather than to speculate in public, but when you are speculating, make it crystal clear--readers aren't exactly dwelling on every nuance.

BTW I think Jancis' comments may have been provoked by an even more sensationalist documentary shown over here a few days ago. I presume you can get it here unless it is blocked for those outside the UK for commercial reasons: http://tinyurl.com/6bnrsz . It seems to me that it is the yeast suppliers that are to blame for any misinformation that is being reported by this documentary and, to a lesser extent, by Jancis.

BTW I think Jancis' comments may have been provoked by an even more sensationalist documentary shown over here a few days ago. I presume you can get it here unless it is blocked for those outside the UK for commercial reasons: http://tinyurl.com/6bnrsz . It seems to me that it is the yeast suppliers that are to blame for any misinformation that is being reported by this documentary and, to a lesser extent, by Jancis.

Ach! Need Windows Media Player and I am on a real operating system--a Mac.

...Soapbox moment: Please correct your friends if they say . . . .
'Yeasts add flavor." They do not, any more than bread yeasts flavor your bread....

I generally agree, but with the following exceptions: Yeast autalycis (sp?) in bottle fermented bubblies and when some winemakers choose to leave the wine on the lees for extended periods, even stirring on occasion.

...Soapbox moment: Please correct your friends if they say . . . .
'Yeasts add flavor." They do not, any more than bread yeasts flavor your bread....

I generally agree, but with the following exceptions: Yeast autalycis (sp?) in bottle fermented bubblies and when some winemakers choose to leave the wine on the lees for extended periods, even stirring on occasion.

Howie, to the best of my knowledge, aromatics that come forth both by autolysis and extended ageing on the lees are not introduced or formed by the lees. What lees can do, on a molecular basis via enzymatic activities, is to release or break bindings that exist between aroma and glucosis molecules, thus "liberating" aromas. Maybe they are also kind of catalysts for aromas to change into secondary/tertiary flavours. But even then: the aromatics come from what's in the wine, never from the lees themselves.

[David M. Bueker]

The article exposes one simple truth about human beings: they are always looking for the man behind the curtain, and deathly afraid of the evil that he may do.

Technology can be abused. So can a lack of technology. There are a number of lazy producers who profess a philosophy of minimalism, and whose wines are filled with VA, brett, unfermented sugars and/or unnecessary sediment.

Can you say Cotturi?? Don't think he's par5ticularly lazy, but pretty much you describe his wines.
Tom

We have used different yeasts on the same lot of wine. In 2005, we used three different yeasts on one lot of viognier, D2, Epernay, and one barrel of native yeast. There were obvious differences while the wine was fermenting and immediately after fermenation. With some time in oak (neutral oak only) those qualities faded as the exotic fruit recovered and grew in strength. We blended the lots before bottling, of course, so did not have the opportunity to study that further. Every year we choose different yeasts for our various reds, but seldom do a side-by-side comparison. The effect of the yeast is most apparent when the wine is young, and it fades with even 6 months bottle age. The effect of the yeast is due to its conversion properties--does it run hot or cold, slow or fast, its nutrient requirements, etc. Depending on its performance a yeast may enhance floral properties (even in reds) color, pepper, or tannin.

This is pretty much what my understanding from talking to winemakers..it makes a difference early on, but sorta fades away w/ time.

I am disappointed that Robinson would say something like this, and is apparently earnest. It is complete and utter flapdoodle and unworthy pot-stirring, very disappointing journalism. .

She had deadline for a column coming up & she had to write about something.

What I found interesting in the article was the comment by the NZ winemaker:

One prominent New Zealand winemaker claims, for example, that he can make any required style of Sauvignon Blanc from exactly the same grapes, provided he can choose the yeast.

So he claims he can make a variety of SauvBlancs, based on his yeast choice. So what's the matter w/ diversity?? He can make a variety of SauvBlancs, based on his choice of barrels. Is that bad?? Jancis decries the wines all tasting the same, but if choice of yeasts can give you a diversity, whatsa matter w/ that, Jancis??
Tom

Here's an excerpt from "Talk Dirt To Me" by Harold McGee and Daniel Patterson, which appeared in The New York Times. Complete story here.

Most of the earthy and mineral aromas and flavors that we detect in wine actually come from the interaction of the grape and yeast. Yeasts metabolize the grape sugars into alcohol, along the way freeing up and spinning off the dozens of aromatic chemicals that make wine more than just alcoholic grape juice. It’s because of the yeasts that we can catch whiffs of tropical fruits, grilled meats, toasted bread and other things that have never been anywhere near the grapes or the wine. The list of evocative yeast products includes an organic sulfur molecule that can give sauvignon blancs a “flinty” aroma. And there are minor yeasts that create molecules called volatile phenols, whose earthy, smoky flavors have nothing to do with the soil but are suggestive of it, especially in wines from the southern Rhone.