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Dear Wine Wizard,
Though most of us think “grapes” when we think wine, I live in
Michigan and can’t help but notice that wineries out here make wine out
of a lot of other fruits, like cherries and peaches. I’ve even heard of
dandelion wine and wine made from grass clippings — can you make wine
out of anything?
Sharon Freed
Omena, Michigan
The Wine Wizard replies: A dear professor of mine in the
Department of Viticulture and Enology at University of California at
Davis used to say, while pointing down at his wooden podium,
“Technically, you can ferment anything, even this tabletop here.”
Smirking slightly he added, “Provided you can find the right
micro-organism to do it.”
What Dr. Kunkee was trying to
point out was that while none of us would try to make a drinkable wine
out of wood, there are certainly micro-organisms out there that can use
some of the carbohydrates in wood (and almost anything else) as an
energy source. These microbes might not be able to survive on wood
alone and they might have a really complicated enzymatic pathway that
allows them to break down the wood into useable bits. However, given
the right conditions and the right organism, it just might be possible
to technically “ferment” wood (or dandelions, grass clippings or
elderberries for that matter).
This is an example of the academic definition of “fermentation”, which
sometimes gets lost in the shuffle of everyday winespeak. Talk to a
knowledgeable microbiologist and she will tell you that fermentation is
“a microbially-brokered metabolic breakdown of a nutrient molecule
through an energy-yielding pathway” . . . or something to that effect.
In plain English, if a bug (bacteria or yeast) eats something, gets
energy from it and excretes something else out the other end in the
process, you’ve got fermentation.
The conversion of sugar to alcohol, as in winemaking, is the hands-on
model with which most of us are familiar. Lucky for us wine lovers,
it’s also a fermentation that tends to have pleasant results. If you
present the right microbe (say your typical Saccharomyces cerevisiae
wine yeast) with the right set of conditions (say, a freshly-pressed
barrel of 22% sugar Chardonnay grape juice) you’ll end up with an
aqueous solution of acid, aromatic compounds and about 11% alcohol — in
other words, wine.
Other fermented beverages include beer and sake, while cheese, olives
and even some sausages and deli meat are considered “fermented” when
defined in the non-booze-centric sense. Cheese is simply what results
when bacteria turn the lactose in milk into lactic acid, separating the
liquid milk into solid curds. The famous dry-cured Fellino salami of
Parma, Italy owes its tang to various strains of indigenous mold and
bacteria. When we talk about the “secondary fermentation” or
“malolactic fermentation” we really mean the common metabolic process
through which bacteria eat the naturally-present malic acid in wine and
spit it out as lactic acid. Even if it’s not yeast turning sugar into
alcohol, it’s technically still called a fermentation.
The bottom line is that yes, you technically can “ferment” dandelions,
elderberries, grass clippings and other such ingredients. They have
sugars and acids that your friendly neighborhood bacteria, yeast and
molds will love to munch on — just check out your compost pile to see
some serious fermentation in action. When you’re looking for a certain
end product and want it to be drinkable to boot, it’s important to
select the right microbe for the job, give it the right starting
conditions and carefully control the fermentation to help your microbe
deliver the results you’re looking for.
Stripped to its essence, here’s how to make wine: Select your starting
material with extreme care and get to know it intimately so you will
know how it will respond to fermentation. Tweak that raw material if
need be (and, if you’re a commercial winemaker, as the law allows) to
enable a harmonious end result. Make sure that your starting material
is only visited by “good” microbes that will get the job done in a
healthy manner and do your best to help these microbes work in a
healthy manner. Give only a gentle nudge when necessary and once the
microbes have done their work, protect your new store of ephemeral
fermented goodness from oxygen, light and bacterial scavengers that
might harm it.
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