The Aviation → pre-Prohibition cocktail = gin, lemon, maraschino liqueur, crème de violette
Chemists from UC (Cincinnati!) discovered flavor differences btw pure vodkas (comprising only ethanol & water) depend on strength oh hydrogen bonds btw the molecules!
“The human relationship with alcohol is a hologram for our relationship with the natural world, the world that made us and the world we made.”
Yeast
Cerevisiae of Saccharomyces cerevisiae derives from cerveza— beer, which it was used to make
Science of fermentation of beer was simultaneous with research into metabolism, biochemistry, cell bio (Pasteur, Schwann, Koch)
Phylogeny of yeasts → domesticated initially in Africa 12k years ago, then sake yeasts branch off, then wine → clusters of strains that make same product
Artificial selective pressures → optimized enzymes in fermentation pathways
Sugar
Must break starches down to sugar before yeas can ferment it into alcohol (whether grain → beer, rice → sake)
Most cultures use some simple sugars directly to produce alcohol (fruit, agave, even horse milk)
Japan: koji (Aspergillus niger) turns rice to sugar; turns out to be much more efficient than European method (malting) at doing the same to grains
Grape = ideal fruit, bc high sugar, grows well, interesting flavors, mostly pulp
Few esters (unlike apples), which are destroyed during fermentation → esters created during the process
All wine-making varieties = cultivars of same species
Malting = turning barley to sugars (barley is ideal grain over wheat, corn, oats)
Used to make whiskey— basically distilled beer
Trick the seed into thinking it’s sprouting → releases enzymes like amylases to break starches into sugars, stop process before the seed metabolizes the sugars (as peat?)
Similar to what koji does— when analyzing genome/changes with domestication, found changes to metabolic enzymes involved w production of MSG (umami flavoring in miso, sake)
Now some attempts to make beer without malting, using enzymes → more efficient, cheaper
Fermentation
Yeast evolved to produce ethanol as byproduct perhaps to easily dissipate waste products (evaporates fast?) → happened to be suited to rise of fruits when angiosperms came around
Yeast are able to produce and consume ethanol!
Different strains → different flavors (also dependent on conditions)
Yeasts “liberate”/make volatile many of the scent-producing compounds in juice
Some fermentations also aided by bacteria (rum, esp bc made directly from cane sugar; wines)
Double dispense → pour an almost full pint of beer (from the tap), let it sit for 3 min, then top it off off: liquid from second pour slips under first foam, pushing it up and sealing the new foam under, slowing CO2 diffusion → stiffer foam
Distillation
Challenging to maintain consistency of single malt whiskeys— can’t just change ratio of what you’re mixing! Depends a lot on standardization of distillation (≈ factory-like process)
Distilling = concentrating, gets alcohol content up (after fermentation which usually maxes out at ~15%)
Basic idea: vaporize the ethanol and interesting stuff (congeners) from water
Azeotropic limit = max proof of alcohol at 194.4, when vapor and water have same ethanol concentration
Proof just = 2x percent alcohol by volume in the US
Different spirits distilled in different set ups- batches, continuous, diff numbers of pots or column, cycles
Column-bases still → allowed for fractional/continuous distillation, by adding ledges into neck of still
Art form = deciding when to make the cut points to keep the middle part that you drink
Copper used bc pulls sulfides out of solution
Aging
Aging in wood gives red wine, Scotch, cognac their “coconutty, round, lush mouthfeel” by adding lactones
Also many other chemical changes
Special rules for type of barrels (new vs old, type of wood, charred) to age Bourbon, Scotch in
Barrel-making is an art form in itself— choosing the specific tree, heating and cooling to bend wood, ultimately bound & watertight with no nails or glue (just flour)
Differences in heat, pressure → spirit loses different amounts of water or ethanol to wood
Cellulose and hemicellulose parts of wood break down into sugars, but lignin contains vanillins, other aromatic aldehydes (→ esters when mixed with acids, fruity & tart) and tannins
How to produce something that tastes old without aging?
Extremely hard to describe how things smell— usually by metaphor, but even that’s incredibly individual and subjective
Very little agreement even between experts when blind-tasting wine
Aroma and flavor highly influenced by color
Experts differentiated from novices more by their ability to describe flavor than actually identifying different wines
Ethanol activates sweet and bitter receptors, but also acts as irritant → nocioception mechanism, independent of taste
Olfaction is only direct sense, in that what stimulates olfactory neurons is a physical part of what we are smelling
“Wheels” of flavor/scent give us common language to describe what we sense
Can work with panel of tasters and flavor references to establish agreement on aromas → actually can distinguish wines by terroir (regionality/microclimate)
Ultimate goal = map specific molecules to each flavor → figure out cheaper ways of getting what makes gives spirits their desired taste
Body & Brain
How to set up random, blinded trial to study effects of ethanol consumption?
Use cold vodka/tonic and tonic (people can’t tell difference)
Actually have four groups: based on what subjects get and what they expect
Expectations (what they perceived to be drinking) = critical to effect of ethanol
Observable effects of alcohol are very predictable, but unknown mechanism of action for ethanol in the brain