Hanes's Electric Kool-Aid Acid Test
(Originally published July 2003)
Hanes talks a lot of shit about wine. Leather accents this, high-toned that, no it's not raspberry it's blueberry fruit. Read enough of this blather and it can drive you to drink. High ranking among the pedantic pleonasm Hanes passes off as wine reviews is his mention of things in a wine such as acidity. Now, while Hanes is no scientist (the lowest grade he received in college was a C- in astronomy), it serves no one to discuss an aspect of wine while assuming its mention is understood. Hence, Hanes will now intrepidly delve into the role of acidity in wine.
Why is acidity important? It is a major component of how a wine tastes and perhaps the greatest factor in how it will taste with food. That should be enough, right? Hell, Willie Gluckstern wrote a whole book, The Wine Avenger, basically to make the latter point. Anyway, the topic gets confusing right away because, first, acidity occurs naturally in grapes but can also be artificially adjusted by the winemaker and, second, there are many type of acids involved. No, not "Uncle Jerry's Electric Froot Juice," something, err, more organic. Although that's not a bad idea either.
A wine with the proper amount of acidity should taste clean, crisp and fresh. Too much acidity and the wine will taste harsh, crabbed, tart and too piercing. Too little acidity and the wine is flat and bland. Of the four tastes -- sweet, bitter, salty and sour (plus the contested "umami" which is believed to be responsible for the savoriness of some foods, initiated by the compound glutamate) -- acidity creates a tangy sour taste. Acidity is tasted on the sides of the tongue. Acidity usually creates a dry, tingly feeling.
The basic types of acid found in wine are tartaric, malic, lactic, acetic and citric (there are others but they don't merit mention here). Natural grapes themselves possess tartaric, malic and trace amounts of citric, with tartaric being the most predominant (tartaric acid exists in almost no fruit but grapes). Lactic and acetic acids are produced during fermentation.
These types of acid break down into two categories, nonvolatile (or fixed) and volatile. Tartaric and malic acids are nonvolatile, in that the do not boil off when heated (important during the fermentation process which can be very hot, "fermentation" being derived from the Latin fervere, to boil).
As if you couldn't guess, volatile acids do boil off when the liquid get hot. Lactic acid can be volatile. Too much volatile acidity is no good because it makes the wine excessively sour. This is why it is a good thing that a lot of acetic acid can boil off during fermentation -- you want to get rid of the volatility in the wine. Thus, too cool a fermentation may risk leaving too much volatile acidity in the wine. Overall, some volatile acidity is good, particularly for increasing the wine's smell. But, as the desired amount usually occurs naturally enough, volatile acidity is more often than not a sign of bacteriological taint during the winemaking process. There are many recent technological advances that allow wineries to remove volatile acidity from their wines. Debate rages whether or not these processes strip more out than they should.
Here, things get real geeky. Winemakers, and the people who love them, measure what is called "total acidity" which is the sum of nonvolatile and volatile acidity. This is measured as a percentage or by grams per liter. While it makes sense for a winemaker to measure such things to achieve a harmonious end product, normal drunks like you or Hanes do not need to fetishize such information. Just note in passing that the goal is well-balanced total acidity and pH.
How does acidity occur naturally? Weather is a huge part of this. Typically, grapes grown in warmer regions develop lower levels of acidity because the fuller ripeness of the grapes means more sugar in them. In cooler regions, the sugar levels do not develop so powerfully, allowing the acidity to shine.
Malic acid is the easiest acid to perceive. It is particularly sensitive to climatic conditions and too much malic acid makes the wine taste green or sour. Less than fully ripe grapes thus need to get their posses together to give the malic acid a strong beat down. Normally a lot of malic acid is respired by the vine during grape ripening but sometimes up to 30% of the malic acid will evaporate during fermentation. If there is still too much malic acid after this, it is time for the process that changed the way we drink wine, yes, "say hello to the winemaker's little friend" -- it's time for malolactic fermentation! This is a natural process that converts harsh malic acid (such as also found in apples) to creamy lactic acid (such as also found in milk) via a post-yeast fermentation brought about by God or a strain of lactic bacteria. Watch those wrinkles disappear! Hey, kids, can you say "buttery Chardonnay"?
In any event, wines with less malic acid to start with (think colder regions such as Chablis or other parts of Burgundy) will change less in character than wines with more malic acid (think warmer regions such as Napa Valley or Barossa Valley). If, after ripening, there remains a good deal of malic acid in the grapes allowing or inducing malolactic fermentation will continue to change the wine's nature even if the grapes are riper. This partially explains why Chardonnay wines from places like California, Chile or Australia may taste very similar as the grapes achieve similar physiological ripeness in these places (yes, with exceptions).
Acidification (also called acidulation -- kind of like adulation adds to Hanes, acidulation adds to wine) is the addition of acids to grape must or wine. This is sometimes permissible, especially in warmer regions where natural acidity may end up being too low or a longer growing season was required to attain maximal flavor extract. Think of this as the opposite of chaptalization, when sugar is added to wine to sweeten the final product. Acid blends come in many different ratios, usually exclusively tartaric but at times including malic and citric acids. Acids are mainly added before fermentation yet can also be added selectively during or after fermentation. Rules governing acidification vary from region to region (go figure).
Adding citric acid to the wine gives it freshness and may highlight certain flavors in which citric acid is dominant. These include blueberry, currant, gooseberry, kiwi, raspberry and strawberry fruit as well as citrus fruit (grapefruit, lemon, lime, orange, tangerine). Think about wines you have deemed to have high acidity and see if you notice more of these fruit flavors than in less acidic wines. Hmmm...
Processes such as "cold stabilization" can also be used to reduce tartaric acid salts and increase microbiological stability. Or one can add even more stuff like calcium carbonate, acidex or potassium bicarbonate. (Yeesh! How does the grape juice fit in the bottle?) Note that deacidification is a common practice world-wide.
In the end, a "balanced" finished wine should possess acidity in proper proportion to the level of sugar and sweetness (as well as the heaviness of alcohol). One illustration of this is that sweet white dessert wines have more total acidity than dry white table wines but because the sugar levels in the former are dramatically higher than in the latter the higher acidity is difficult to perceive. One could persuasively argue that the balance between sugar and acidity is the most important relationship in any wine. Much of this is driven by the type of grape involved and its own inherent propensity towards lower or higher sugar and acidity. For the winemaker achieving this balance is an ongoing struggle, from deciding when to pick the grapes through the fermentation process and beyond. Who says winemakers have it easy?
Furthermore, acidity plays a paramount role in the longevity and aging of wine. It can stop or retard the growth of bogus microorganisms in wine. The "yeast beast" called Brettanomyces (or simply "Brett") can be checked in part by higher acidity. Acidity helps to stabilize a wine -- when you think of white wine that can age forever, it's Loire Chenin Blanc and German Riesling, not low acid Australian Chardonnay or Californian Viognier. Additionally, too much lactic acid (e.g., Chardonnays having undergone full malolactic fermentation) may cause milky flavors to appear over time and shorten the lifespan of a wine. It's not just the presence of acidity per se in a wine that guarantees ageability, it's the type of acid and amount of diacetyl produced by malolactic fermentation.
So, when Hanes or anyone else mentions the level of acidity in a wine, what's really up with that? What's up is that more and more wineries are producing less acidic, more fruity wines that are s-m-o-o-t-h but often lack zip, punch and the stuffing to provide a useful foil to food during a meal (never mind reach an old age). Generations weaned on Coke and Pepsi (Hanes likes RC!) prefer their drinks sweet and soft and that's in part what wineries are reacting to, willingly or unwillingly. Acidity is overall a good thing and not something to avoid. Once you exercise your acidity muscle a bit, you'll find that not only will you enjoy higher acidity wines at the dinner table, you'll prefer them on the summer deck or in front of the roaring fireplace too. Low acidity wines have their place, and Hanes luvs many of them, but if you want a syrupy sweet drinkie-drinkie you might be better off leaving the cork in the bottle and having that rum and Coke instead. Mmmm, rum and Coke...