Lychee, Saddle Leather, Pencil Lead
posted by philip in Snooth, Wine
Mark and I are currently in Napa. In between the business wheeling and dealing we’re hitting the wineries at a pace. We’ll write more about the trip after we’re back (Mark’s first post!), but listening to the tourists in the tasting rooms reminded me of an article a friend sent last week.
Dried rose petals, wet wool, silex, gun flint: why do wine critics talk like that?
Apparently, the most commonly observed fragrances found in wine includes: toast, butter, vanilla, citrus, apples, cherries, pears, honey, herbs. On the site we’re seeing lots of searches for vanilla, toast, apples and cherries.
Some of these aren’t too hard to explain, for example ‘butter’ (think california chard) is actually diacetyl, a by-product of secondary malolactic fermentation, which is what makes these chardonnays so smooth and rich (versus the green apple tastes they have before that).
As for pencil lead and other esoteric tastes, no one knows why or how the wines get these tastes exactly, but there’s a good degree of correlation between critics. In the interim it’s just fun to listen to people use them.
Although the exact chemical source of all aromas found in wine have yet to be identified, it is inaccurate to say that “no one knows why or how the wines get these tastes exactly”. Wine researchers such as Sue Ebeler and Linda Bisson at UC Davis, and many flavor chemists have spent their entire careers studying the biological and chemical sources of the molecules that create the complex matrix that make up wine’s aroma profile.
Many of the chemical components (terpenes such as linalool, sulfur compounds such as methoxypyrazines) are synthesized directly in the fruit, others are metabolic products of the yeast, lactic (such as diacetyl) or “spoilage” bacteria (such as phenols contributed by brettanomyces), others are contributed by oak barrels (such as vanillin), while still others are the result of chemical reactions among the former products (esters such as ethyl acetate). As a result a wine’s final aroma is the result of the interaction between components of the grapes and those produced during winemaking process, fermentation and aging.
Tom Stevenson has an excellent article on wine aromas and tastes here - http://www.wine-pages.com/guests/tom/taste5.htm.
Lisa
Thats a great post that you reference, and it really shows just how much is understood about a wines tastes, however, and this is something I know from my own days as a chemist, there’s a heck of a lot we don’t understand.
An example from the wine-pages site:
“BASIL - Often found in wines from Provence, Spain and Italy.”
Good to know, but it doesn’t tell me what chemicals actually cause this.
The fact that there’s correlation between tasters does imply these chemicals actually exist in the wine, but for tastes with low correlation? Is one of the tasters simply interpreting them wrong? If you tell me its peach, and I say pear, does that mean both sets of chemicals are present, or could one of us be wrong? Could 50 of us be wrong?