Is acidulation bad?

Yeast selection and then laboratory breeding is no different then selected the best suited clone for a specific vineyard site.

Salute

From my perspective, thinking of European vineyards producing AOC/DOC wines, it is far from the same thing. Selecting a yeast to boost, say, red fruit jam seems to me a big degree of manipulation different from selecting the clone of an authorised variety which is best suited to the terroir.

I've been experimenting with different yeasts in my home wine making the past few years. I've discovered (the hard way) that several of the newer strains of yeast require the addition of yeast nutrient (Diammonium Phosphate (DAP)) to ferment properly. Without these additions the fermentations can stop or produce hydrogen sulfide (rotten egg smell). The older, traditional strains, such as Pasteur Champagne, Montrachet or Prise de Mousse (E.C. 1118) did not require this addition. I think the use of the newer yeasts (BM-45, GRE) have improved the wines I've made, but I always cringe when I have to add something else to my wine.

I have read elsewhere that the jury is still out on the impact of yeast to the final product. Many ITB seem to believe that the differences attributed to yeast strains become indistinguishable after the wine ages about 2 years.

A knowledgeable acquaintance tells me that “..... The sun in Argentina, and parts of Australia, Portugal, Spain, and Italy, is such that over ripe grapes have much more sugar (14 - 15% potential alcohol) and lose much more acidity (sunshine reduces malic acidity). Wines in regions such as Alsace and Germany are, also, almost always made from very ripe grapes, but the climate is colder, so wines become less alcoholic and retain their characteristic natural acidity.”

Does Sunshine really reduce malic acid? My understanding was that phenolic ripeness was predominately a function of sunshine while eleveated sugar/reduced acidity was predominately a function of heat. Obviously the two are intertwined and it is much more complicated than that oversimplified statement. However, long day growing areas such as Germany often reach phenolic ripeness before elevated sugar levels while short day areas often have to wait for phenolic ripeness resulting in lower acidity levels and elevated sugars leading me to believe that the accumulated heat not the sunshine reduces total acidity and I assumed impacted all acidity equally. Is malic acid impacted differently by sunshine such that shade grown grapes grown in the same area would have higher acid from lack of sun and not because of the reduced photosynthesis?

Does Sunshine really reduce malic acid? My understanding was that phenolic ripeness was predominately a function of sunshine while eleveated sugar/reduced acidity was predominately a function of heat. Obviously the two are intertwined and it is much more complicated than that oversimplified statement. However, long day growing areas such as Germany often reach phenolic ripeness before elevated sugar levels while short day areas often have to wait for phenolic ripeness resulting in lower acidity levels and elevated sugars leading me to believe that the accumulated heat not the sunshine reduces total acidity and I assumed impacted all acidity equally. Is malic acid impacted differently by sunshine such that shade grown grapes grown in the same area would have higher acid from lack of sun and not because of the reduced photosynthesis?

I will ask my "source." One more thing he said that may be of interest was that, up until the point of industrial maturity (or thereabouts), sugar accumulates in the grape but, after that, (i.e., during supermaturation) sweetness increases by concentration, not by accumulation.

Tim, I think you need to investigate the subject of yeasts in fermentation a bit more, and not depend on rhetoric from people with agendas.

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.

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.

You know, I have met bakers who were skeptical of these packaged yeasts. One in particular swore by all the microbological activity in her kitchen and left her dough out for days to rise naturally while heaping scorn on all of us who used such packaged monstrosities.

She also enjoyed making quiche with her breast milk. But the two points don't necessarily have to be related.

She also enjoyed making quiche with her breast milk. But the two points don't necessarily have to be related.

Rahsaan, that's oversharing.

You know, I have met bakers who were skeptical of these packaged yeasts. One in particular swore by all the microbological activity in her kitchen and left her dough out for days to rise naturally while heaping scorn on all of us who used such packaged monstrosities.

I used to make bread with a starter (originally from unsprayed grapes). When that died I started using Fleischman's Red Star, a crap commercial yeast, in very small amounts (for a very slow fermentation); I had excellent results. I don't hear rate of fermentation discussed in wine much, oddly, but it's clearly the root of good breadmaking.

I don't hear rate of fermentation discussed in wine much, oddly, but it's clearly the root of good breadmaking.

You're right, Oliver. I don't hear rate of fermentation discussed much either...and it is important. Both rate and consistency.

And the other thing that's not discussed, but is of great importance to sparkling winemakers especially, is what happens to the yeast after it has done its job and sent its soul off to the Great Yeast Heaven.

But winemakers and lab guys get to deal with all that messy behind-the-scenes stuff. WIne geeks get to be philosohical and all existential.

Brian, my girlfriend Marcia (who is a doctor and understand these things far better than I) tells me it's clearer to distinguish between light and heat, avoiding the word sunshine because it contains both and can therefore be imprecise. Light and heat have distinct effects and, as you pointed out, what reduces malic and any other acidity is indeed heat, not light.

Light, through photosynthesis, is crucial to the vine but practically irrelevant (according to Marcia) for the grape itself. As long as the vine receives adequate light, the grape could (theoretically) be in the dark and yet still mature as long as it receives heat. If, conversely, a vine were to receive adequate light in an environment without heat, it would grow normally, but the fruits wouldn't mature. Also, heat converts an already existing non-sweet carbohydrate present in immature fruit into the sweet carbohydrate (sugar) of mature fruit. The only part of your post that didn’t jive with her explanation was the statement that phenolic ripeness was a function of light. If she's right and light is not important to the grapes, phenolic ripeness of the grapes would be the result of light on the vine, not the grapes. In any case, looking for the answer in earlier board posts, I found this interesting clarification from James Lester dated January, 2007:

If I may weigh in here as a Pinot grower and maker, I think the weather under which the grapes ripen has much to do with style of wine. Warm regions make fat, low acid, high alcohol wines because there are more heat units and sun, and a longer growing season in which to ripen the fruit. As the grapes ripen, they lose acidity and gain sugar. Growers hope that the flavor development will coincide with the ideal fruit acid/sugar balance. In warm climates the grapes achieve physiological maturity before they achieve phenolic maturity. I am defining "physiological maturity" as the correct sugar/acid/pH balance that indicates ripeness and time to harvest, and phenolic maturity as ripe skins (tannins) and full flavor development in the grapes. If one harvests at physiological maturity in a warm climate, the result is a wine that has all the right numbers in the lab, but lacks rich flavors and a mid-palate impression and long finish (and ageability). In a warm climate, if one hangs the grapes past physiological maturity to achieve phenolic maturity, one is confronted in the winery with over-ripe fruit physiologically, that does at least have ripe tannins and full flavors. But now the winemaker is dealing with grapes that have too much sugar (potential alcohol in a dry wine) and too low acidity. So they add tartaric acid to achieve the balance that nature would have provided naturally in a cooler climate, and end up with a wine that has very sweet jammy fruit flavors and a thick syrupy texture. Some folks like this style of wine. They don't age well, but who cares if you want something to drink soon that offers big flavors and big palate impression.

If you like wines with natural acidity and bright fresh fruit flavors and lower alcohol, stick with cool climate wines. Think Oregon, New York, Michigan, New Zealand, Northern Italy, Germany, and of course most of northern and western France. If you like the type of wine described above, buy California, Australia, Chile, and most of Spain.

If I may weigh in here as a Pinot grower and maker, I think the weather under which the grapes ripen has much to do with style of wine.

Would absolutely agree with that statement. And for luminosity versus heat. Case in point: Mendocino Ridge, where the vineyards have to be above 1200 feet (or in other words, above the fog layer). They sit on top of a series of mountaintops, don't have benefit of the valley warmth or the fog cushion. As a result, exceptionally high luminosity, but extremely cold climate, since they are exposed to the severe Pacific Coast cold winds.

If you like wines with natural acidity and bright fresh fruit flavors and lower alcohol, stick with cool climate wines. Think Oregon, New York, Michigan, New Zealand, Northern Italy, Germany, and of course most of northern and western France. If you like the type of wine described above, buy California, Australia, Chile, and most of Spain.
Brian, my girlfriend Marcia (who is a doctor and understand these things far better than I) tells me it's clearer to distinguish between light and heat, avoiding the word sunshine because it contains both and can therefore be imprecise. Light and heat have distinct effects and, as you pointed out, what reduces malic and any other acidity is indeed heat, not light.

Light, through photosynthesis, is crucial to the vine but practically irrelevant (according to Marcia) for the grape itself. As long as the vine receives adequate light, the grape could (theoretically) be in the dark and yet still mature as long as it receives heat. If, conversely, a vine were to receive adequate light in an environment without heat, it would grow normally, but the fruits wouldn't mature. Also, heat converts an already existing non-sweet carbohydrate present in immature fruit into the sweet carbohydrate (sugar) of mature fruit. The only part of your post that didn’t jive with her explanation was the statement that phenolic ripeness was a function of light. If she's right and light is not important to the grapes, phenolic ripeness of the grapes would be the result of light on the vine, not the grapes. In any case, looking for the answer in earlier board posts, I found this interesting clarification from James Lester dated January, 2007:

If I may weigh in here as a Pinot grower and maker, I think the weather under which the grapes ripen has much to do with style of wine. Warm regions make fat, low acid, high alcohol wines because there are more heat units and sun, and a longer growing season in which to ripen the fruit. As the grapes ripen, they lose acidity and gain sugar. Growers hope that the flavor development will coincide with the ideal fruit acid/sugar balance. In warm climates the grapes achieve physiological maturity before they achieve phenolic maturity. I am defining "physiological maturity" as the correct sugar/acid/pH balance that indicates ripeness and time to harvest, and phenolic maturity as ripe skins (tannins) and full flavor development in the grapes. If one harvests at physiological maturity in a warm climate, the result is a wine that has all the right numbers in the lab, but lacks rich flavors and a mid-palate impression and long finish (and ageability). In a warm climate, if one hangs the grapes past physiological maturity to achieve phenolic maturity, one is confronted in the winery with over-ripe fruit physiologically, that does at least have ripe tannins and full flavors. But now the winemaker is dealing with grapes that have too much sugar (potential alcohol in a dry wine) and too low acidity. So they add tartaric acid to achieve the balance that nature would have provided naturally in a cooler climate, and end up with a wine that has very sweet jammy fruit flavors and a thick syrupy texture. Some folks like this style of wine. They don't age well, but who cares if you want something to drink soon that offers big flavors and big palate impression.

If you like wines with natural acidity and bright fresh fruit flavors and lower alcohol, stick with cool climate wines. Think Oregon, New York, Michigan, New Zealand, Northern Italy, Germany, and of course most of northern and western France. If you like the type of wine described above, buy California, Australia, Chile, and most of Spain.

Agree with the sentiment, but don't agree with the overly generalized conclusions. Shame on the author for saying "[all] California, Australia, Chile" and then saying "most of Spain." Hey, if you're going to make sweeping generalizations, don't then except some of your sweep for certain areas.

There's an awful lot of space covered by "California", and not all of it is the same. Far from it. See the Mendocino Ridge example cited above.

This wine thing is tough, because people tend to preach to their prejudices, and end up over generalizing to those prejudices. This author began well, but then subsided right back to the prejudices and sweeping claims.

Hoke, I should have left out the second paragraph! But the distinction between phenolic and physiological maturity made things much clearer for me.

Re heat vs light:
As always the Oxford Companion has some useful points, under 'Climate and Wine Quality.' I wonder if we will find out more about this in the future; the contributor to the OCW on this issue says heat and light are essentially aspects of the same thing, but I can't help thinking that the relative latitude of eg Burgundy and even cooler parts of California is significant (longer days further north).

A knowledgeable acquaintance tells me that “Traditionally, there was a point called the ‘industrial’ level at which winemakers considered a grape to be ripe. Essentially, this was the point at which there was equilibrium between the level of sugar and the amount of acidity, and was used to establish the date on which the grapes should be picked. But, then, new studies showed that grapes picked at the industrial level did not have sufficient phenolic maturity (tannins and color) and aromas, resulting in wines that were deficient in this respect. A move towards picking riper grapes emerged, and is now prevalent in almost all wine regions. One of the technical reasons for Michel Rolland’s fame is precisely this: over 30 years ago, he began to pick over ripe grapes in Bordeaux in order to produce 'better' wine. In the preface to the Larousse wine guide, Michel Rolland describes how he noticed that wines tasted better in dryer years because, in these years, growers did not rush to pick as soon as industrial maturity occurred, letting grapes hang a little while longer. The sun in Argentina, and parts of Australia, Portugal, Spain, and Italy, is such that over ripe grapes have much more sugar (14 - 15% potential alcohol) and lose much more acidity (sunshine reduces malic acidity). Wines in regions such as Alsace and Germany are, also, almost always made from very ripe grapes, but the climate is colder, so wines become less alcoholic and retain their characteristic natural acidity.”

Perhaps it's obvious, but Rolland's remarks are an expression of a preference, not a reference to some kind of standard. I love his defining old-fashioned ripeness as 'industrial,' whereas wines taste 'better' in hotter years.

Picking at higher Brix is done because certain critics like the resulting wines.

Boy, do I get headaches from these discussions.

I cannot agree more with Hoke. (I do like Rahsaan's quiche recipe, though.)

The ideal temperature for a vine to function during its “growing season” is 50 deg F. If during its growing season it is exposed to extreme heat or cold the vine will shut itself down. In vineyards where the nights are fairly warm, the vine remains very active. Since there is no sunshine for the vine’s green parts to perform photosynthesis, it has to find an alternate way of getting “energy” to its active cells. So it takes some of its malic acid and converts it into needed “energy” for the active cells of the plant. (Just think what happens in your muscle cells during a real hard workout). Therefore the TA is reduced somewhat. In vineyards where the nights are fairly cool the vine might go into a somewhat “sleep” or “rest” mode. Therefore the TA remains stable.

Salute

Perhaps it's obvious, but Rolland's remarks are an expression of a preference, not a reference to some kind of standard. I love his defining old-fashioned ripeness as 'industrial,' whereas wines taste 'better' in hotter years.

Picking at higher Brix is done because certain critics like the resulting wines.

Sorry, perhaps I wasn't clear enough, I never said it was Rolland who came up with the term industrial maturity, or that wines tasted better in hotter years.

I don't know how widespread the expression was/is but the concept is clear: the industry tended to pick grapes when they were physiologically ripe (i.e., correct acid/fruit balance), not when they were phenolically ripe. Rolland noticed that people (and he as well, presumably) tended to prefer wines in drier years when grapes were picked later, past the point of physiological maturity and closer to phenolic maturity. Thus began the move to pick later. I have been speaking of "overripe" grapes but it would have been more accurate to qualify that as "physiologically overripe."

In a nutshell, what I have learned from this thread is that there are two kinds of ripeness that, depending on the climate, may be at greater or lesser odds. To simplify, growers used to pick at physiological maturity until the influence of Rolland/Parker pushed the industry in the direction of picking at phenolic ripeness (physiological overripeness). For each grape, both maturities will only coincide in certain climates. If they don't coincide, the winemaker has a box of tools to rectify the situation, but at an unknown cost to longevity and ultimate complexity. Heat favors physiological maturity and light favors phenolic maturity. In hot and sunny climates, grapes reach physiological maturity earlier and become physiologically overripe by the time they reach phenolic maturity, with high alcohol and low acid, requiring acidulation. In colder climates, physiological maturity is harder to achieve, but there is a greater chance of making physiological and phenolic maturities coincide. In Germany and Alsace, wines tend to have excellent acidity because there is enough light to bring about phenolic maturity yet not so much heat that physiological maturity will overtake it.

Sorry, perhaps I wasn't clear enough, I never said it was Rolland who came up with the term industrial maturity, or that wines tasted better in hotter years.

I think you did, actually; 'Michel Rolland describes how he noticed that wines tasted better in dryer years because, in these years, growers did not rush to pick as soon as industrial maturity occurred, letting grapes hang a little while longer.' But I accept that he didn't actually say that.

I don't know how widespread the expression was/is but the concept is clear: the industry tended to pick grapes when they were physiologically ripe (i.e., correct acid/fruit balance), not when they were phenolically ripe. Rolland noticed that people (and he as well, presumably) tended to prefer wines in drier years when grapes were picked later, past the point of physiological maturity and closer to phenolic maturity. Thus began the move to pick later. I have been speaking of "overripe" grapes but it would have been more accurate to qualify that as "physiologically overripe."

I have never seen a precise definition of 'physiological ripeness', which of course means that physiological over-ripeness is similarly vague. The Oxford Companion describes physiological ripeness as a term 'loosely used by New World winemakers to contrast with ripeness measured by the normal analytical measures...'

In a nutshell, what I have learned from this thread is that there are two kinds of ripeness that, depending on the climate, may be at greater or lesser odds. To simplify, growers used to pick at physiological maturity until the influence of Rolland/Parker pushed the industry in the direction of picking at phenolic ripeness (physiological overripeness). For each grape, both maturities will only coincide in certain climates. If they don't coincide, the winemaker has a box of tools to rectify the situation, but at an unknown cost to longevity and ultimate complexity. Heat favors physiological maturity and light favors phenolic maturity. In hot and sunny climates, grapes reach physiological maturity earlier and become physiologically overripe by the time they reach phenolic maturity, with high alcohol and low acid, requiring acidulation. In colder climates, physiological maturity is harder to achieve, but there is a greater chance of making physiological and phenolic maturities coincide. In Germany and Alsace, wines tend to have excellent acidity because there is enough light to bring about phenolic maturity yet not so much heat that physiological maturity will overtake it.

I think the most important aspect of the issue of ripeness is that there is no one measure of it, and that there is no understanding of what constitutes 'properly ripe' in any of the measures. To use the simplest traditional measure, sugar, the 'normal' understanding of proper ripeness has changed from 24 Brix or so to 28 or even 30 Brix, for the same variety (Cabernet Sauvignon) in the same area (Napa). As the Companion says, 'What constitutes the ideal chemical and physical composition of any fruit, including grapes, at this point is a subjective judgement dependent on wine style, fashion and many other factors...'

I don't know that one can separate the effects of heat and light so neatly; I've read a bit about this and it doesn't seem that well understood. (For example, Richard Smart's work suggests that trellising greatly changes the way the plant interacts with its environment, and can change how grapes ripen.) It's a fascinating topic, certainly, and perhaps I'm missing something.

The only part of your post that didn’t jive with her explanation was the statement that phenolic ripeness was a function of light. If she's right and light is not important to the grapes, phenolic ripeness of the grapes would be the result of light on the vine, not the grapes.

I did a little reading last night scanning a number of books about this point to find no agreement among the sources. Some cite impacts of direct light on the berry development, others claim that one can bag the clusters to protect them from birds and the berries will ripen just the same. Not sure that the same definition of ripen is being used in each text.

Sorry, perhaps I wasn't clear enough, I never said it was Rolland who came up with the term industrial maturity, or that wines tasted better in hotter years.

I think you did, actually; 'Michel Rolland describes how he noticed that wines tasted better in dryer years because, in these years, growers did not rush to pick as soon as industrial maturity occurred, letting grapes hang a little while longer.' But I accept that he didn't actually say that.

I think I did not, actually. Not unless drier (my word) means the same as hotter (your word), and not unless saying that growers rushed to pick at industrial maturity (what I quoted Rolland as saying) means the same coming up with the term industrial maturity (which I never wrote).

Sorry, I assumed 'hotter' because we were talking about heat (and light) rather than water. My mistake.

The so called “industrial” standard for ripeness (if by this you mean the traditional Brix to TA ratio) came into existence only because this was “typical” for a specific wine growing region.

Salute

The so called “industrial” standard for ripeness (if by this you mean the traditional Brix to TA ratio) came into existence only because this was “typical” for a specific wine growing region.

Thanks for your clarifications throughout this thread. My understanding is that the so-called industrial standard is not dependent on custom or culture or taste. It reflects a physiological point of inflection in the grape's maturation, different for every type of grape, at which sweetness stops increasing as a result of increasing amounts of sugar, and begins to increase by concentration of the existing amount of sugar. In other words, up to the industrial point, sweetness increases as a result of accumulation; after that, sweetness increases as a result of concentration. Is this true?