On food and cooking the science and lore of the kitchen ( PDFDrive ) 854

bitterness is due to easily extracted caffeine,
the rest to more slowly extracted phenolic
compounds and browning pigments. More
than 800 aroma compounds have been
identified, and they supply notes that are
described as nutty, earthy, flowery, fruity,
buttery, chocolate-like, cinnamon, tea,
honeyed, caramel, bready, roasty, spicy, even
winey and gamy. Robusta coffees, with their
substantially higher content of phenolic
substances than arabicas, develop a
characteristic smoky, tarry aroma that is
valuedindarkroasts(theyarealsodistinctly
less acidic than arabicas). Milk and cream
reducetheastringencyofcoffeebyproviding
proteins that bind to the tannic phenolic
compounds,buttheseliquidsalsobindaroma
molecules and weaken the overall coffee
flavor.
Decaffeinated Coffee Decaffeinated coffee
was invented in Germany around 1908. It’s


made by soaking green coffee beans with
water to dissolve the caffeine, extracting the
caffeine from the beans with a solvent
(methylene chloride, ethyl acetate), and
steaming the beans to evaporate off any
remaining solvent. In the “Swiss” or “water”
process, water is the only solvent used, the
caffeine removed from the water by charcoal

filters, and the other water-solubles are then
addedbacktothebeans.Someoftheorganic
solvents used in other processes have been
suspectedofbeinghealthhazardseveninthe
tinytracesleftinthebeans(around1partper
million).Thecommonest,methylenechloride,
is now thought to be safe. More recently,
highly pressurized (“supercritical”) and
nontoxiccarbondioxidehasbeenused.Where
ordinary brewed coffee may contain 60–180
milligrams caffeine per cup, decaffeinated
coffeewillcontain2–5mg.
Instant Coffee Instant coffee became