Country Wines Workshop - American Chemical Society

Brewing Country Wines
Benjamin F. Lasseter, Ph.D.
Chair, Hampton Roads American
Chemical Society
What is a “country wine”?
• An alcoholic beverage produced at home,
instead of commercially
… possibly using grapes. Not always.
… the result of a very complicated
chemical and biological process…
…that can be done with Medieval
technology.
Alcoholic Brews
Beer
• Lagers
• Ales
Wine
True Mead
• Fruit Wines
• Vegetable
and Herb
Wines
• False
Meads
• Honey
Mead
• Methyglyn,
Melomel,
etc.
Other Fermented Substances
Mash
Exotics
Whisky
Kefir,
Kumis, Viili
Sake
Various
Poisons
How starch becomes sugar
How sugar becomes pyruvate
How pyruvate becomes alcohol
Humans can’t do
this step.
And that’s the SIMPLE model of how starch becomes alcohol! 
The more complex version: How starch
REALLY becomes sugar
And starch is not simple
The sugars in starch
vary in different
species.
And not all the brewing reactions are
done in the same organism…
• Starch is broken to sugar by the fruit or the
grain
• Sugar is converted to pyruvate by the yeast
• Pyruvate is SOMETIMES converted to ethanol
by the yeast
– Yeast won’t ferment if there is too much sugar or
too little oxygen
What determines the type of wine?
• 1. Type of yeast: beer yeast, wine yeast, mead
yeast, cider yeast, sake yeast, et al.
• 2. Sugar source: grains, fruits, vegetables,
molasses, milk, etc.
• 3. Non-sugar flavors: hops, tannin, wood, acid
blends, fruit flavors, spices, etc.
• 4. Quantity and time
A proposition about brews:
Only the type of yeast you use REALLY
determines the type of brew you
create.
The rest just alters the flavor.
All brews made with wine yeast are types of wine, all made
with ale yeast are types of ale.
Barley mixed with grapes and fermented with Belgian ale
yeast is a type of ale, not a type of wine.
Honey fermented with Pasteur Red is a wine, not a true mead.
Yeast in brewing
• It is all the same species, Saccheromyces
cerevesiae (brewer’s yeast)
• Some other yeasts are…
– S. plombe (bread yeast)
– S. telluris
– Brettanymyces bruxellensis 
– Cryptococcus neoformans 
– Candida albicans et al. 
– …and many thousands more.
What difference does yeast make?
Genetic variations make huge differences of
flavor and require different conditions
Temperature
Growth speed
Sugar amount
Sugar type
Flavor compounds produced
Lager yeast
• Lager yeast has a dense protein coat, and is denser than
water. It is also cryophilic.*
• Ferments at the
bottom of vessels
• Preferentially uses
maltose or simple
sugars
Maltose
(a-1→4-glucopyranosylglucopyranose)
Common in grain
Sucrose
(a-1→2-glucopyranosylfructofuranose)
Common in fruit
Ale Yeast
• Ale yeast has less protein content in its cell wall, and hence is
less dense than water. It is generally mesothermic.
• Ferments at the
top of vessels,
foamlike
• Like lager, it
preferentially
metabolizes maltose or simple
sugars
Beers in general
• Because of their preference for maltose, and
their inability to ferment certain flavoring
trisaccharides, lager and ale yeast are
preferred for beer.
• Also display a range of ester synthase
enzymes, yielding flavor overtones
– Propyl acetate (pear) and butyl acetate (apple)
– Ethyl butyrate (pineapple) can be activated, et al.
Wine Yeasts
• Most species of grape have yeast strains
uniquely suited to them
• Example include Côte de blanc, Montrachet,
Flor sherry, and Premier cuvee, among others
• Most tend to be slow growing
• Most tend to have higher alcohol tolerance
– Most wine yeasts tolerate 13% - 18%
– Most lager and ale yeasts tolerate 5%-12%
Wine Yeast
• Wine yeasts preferentially metabolize sucrose and simple
sugars.
• They are slow at using
maltose or lactose
• Varieties exist that range from
cryophiles to mild thermophiles
• Have capacity to produce large
amounts of ester flavors
A few strains of wine yeast
• Pasteur Champagne: ferments dry (less
residual sugar)
• Pasteur Red: ferments fruity (makes more
esters)
• Bordeaux: ferments very dry and very fruity
(extremely high alcohol tolerance)
• Cabernet Red: mild thermophile, high ester
• Assmanhausen Rot: slow growing cryophile
Sugars
• The sugar for fermentation comes from
various plants or animals
• The fermentable sugar is liberated from starch
• Sugar is liberated as mono-, di-, or trisaccharides
– Maltose and sucrose are disaccharides
Sugar sources
• Grains
– Barley
– Wheat
– Rice
– Corn
– Other grasses
Fruits
•
•
•
•
•
Grapes
Apples
Berries
Bananas
And many more…
The sugar source will leave some flavor
…and the yeast enzymes make some
flavor
• EC 3.1.1.67 - fatty-acyl-ethyl-ester synthase
– Esterizes ethanol
to various available
fatty acids
• Atf1p – acetyl transferase
– Esterizes acetate to
various primary alcohols…
…and the strain of yeast matters
• California Ale yeast WLP001 acetyl tranferase
binds isoamyl alcohol better than butanol
– This causes it to have slightly more “banana”
overtone than “apple”
• Irish Ale yeast WLP004 acetyl transferase
binds butanol and propanol better
– It therefore has distinctive “apple” and “pear”
overtones
“Blueberry Yeast”
Blueberry flavor
2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy4H-chromen-4-one
There is a strain of yeast that produces this flavor.
There is another that produces menthol.
…and various additives give some
flavor
The characteristics of your beverage
1. Sweetness: This will be caused by unfermented
(or unfermentable) sugar. “Dry” wines have low
sweetness.
2. Acidity: the pH is lowered by citric, malic, and
tartaric acid
3. Tannin: polyphenol, which tastes dry, and which
acts as a preservative
4. Fruitiness: the esters which have remained or
been formed in the fermentation process
5. Body: the texture of the wine. Alcohol content is
a large contributor to this.
The Goal
• A drink which has some balance to these
characteristics!
Stages of brewing
1. Extracting the sugar: for beer this is called
“mashing” and for wine it is called “pressing”.
2. Innoculation with yeast.
3. Primary fermentation: alcohol level is made
at this point.
4. Secondary fermentation: esters and flavors
develop at this point
5. Consuming. Best left to the masters.
Today’s Recipes
#1 Grape wine: a combination of table grapes,
concord grapes, fox grapes, and muscadine
grapes, with Pasteur Red yeast
- extra sugar is necessary when you use fox
grapes
#2 Banana wine: just bananas! …with
champagne yeast.
- we will need to add acid blend and
tannin, because bananas don’t come with
those
Today’s Recipes
#3 Cranberry/crabapple/rosehip wine: because
it’s just crazy enough that it might work. With
cote-de-blanc yeast.
- This yeast grows slowly and works best with
other fruits than grapes.
- Extra sugar will be needed, because
crabapples impart apple flavor but no sugar
- Rosehips should make this wine somewhat
spicy
Today’s Recipes
#4 Kolsch Ale: This is to show how extremely
similar ale and winemaking are. Made
with WhiteLabs WLP029 German Kolsch
Yeast
– It will mature in two months rather than two years
– The hops blend gives the preservative, instead of
the tannin.
– The barley will also add flavoring, as well as sugar.
In addition
• We will “rack” some previously made wines
– “racking” means “siphoning into a new
fermentation vessel to separate from the dead
yeast”
• We will “bottle” some previously made wines
– Bottling is the last stage of secondary
fermentation. The wines must stay in the bottles
until their flavor is finished developing.
Thank you!
• Dmitry Liskin, for introducing me to the craft
and encouraging me.
• The American Chemical Society, for
sponsoring this event.
…and especially
• Dr. Sumie Shima, for tolerating my midlife
eccentricities.