27.5 Wine and spirits

Grapes

Wine is the fermented juice of a fruit. Many fruits and plants have been used, but the classic wine is made from grapes. The pulp holds the sugar that ferments; the skin and seeds hold much of the flavor.

Wine grapes are Vitis vinifera; table grapes are Vitis labrusca. There are more than 5,000 varieties, each with its own taste and smell. European wines are mostly named for where they come from. American, Australian, South African and New Zealand wines are mostly named for the grape. Grapes as fruit are covered with fruit. see chapter 18: Grapes

Soil, temperature, rain and the way the vines are grown all change a grape's flavor. Winemakers call the land and climate together the terroir.

By harvest, sugar makes up 15% to 25% of a grape. Tartaric and malic acids make up more than 90% of the acid in the juice, and tartaric acid gives most of the tartness. In tasting, acidity means the fresh, sour side of a wine, judged by how well it balances the sweetness and the bitter parts. Two groups of compounds in the skin and seeds shape red wine: anthocyanins give the red color, and tannins give the drying, puckering feel.

Making wine

• Harvest and crush. Grapes are picked in late summer and early autumn, mostly by machine at large wineries. Stems come off first to avoid off-flavors, and the grapes are crushed right away to free the sugar, acid and some skin compounds. Crushing too hard pulls out too many tannins and makes the wine too astringent.
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• White or red. For white wine the juice is taken off the skins so it gains no color or tannin. For red wine, juice and skins ferment together.
• Maceration. Juice is left in contact with skins to soak out color and flavor, cold, warm or with enzymes, before, during or after fermenting. Too long a soak can lower these compounds again, as they join up and drop out.
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• Adjusting. Sugar sets both the strength and the sweetness, and is measured in degrees Brix. Sugar or grape juice may be added. A wine with too little acid tastes flat; too much, unpleasantly sour. Winemakers may add acid, most often tartaric.
• Fermenting. Wild ferments start with other yeasts until the alcohol reaches 3% to 4%; then those die and Saccharomyces takes over. Other winemakers add a chosen strain of S. cerevisiae from the start.
• Malolactic fermentation, as in cider, softens harsh malic acid. It is used on more reds than whites, though oaked Chardonnay often goes through it.
• Aging. Wine matures, often for months or years in barrels, before bottling. Oak gives it tannins and flavors such as vanilla (vanillin), clove (eugenol) and whisky lactone.
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• Clearing. Fining takes out unwanted parts: bentonite clay removes the proteins that cloud white wine, and gelatin, casein or albumin bind extra tannin. Filtering can remove spoilage organisms.
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Air turns the wine's color compounds brown and muddy, which is worst in white wine. Winemakers add sulfur dioxide against browning, against alcohol turning to vinegar, and against spoilage organisms.

Wine is seldom filtered the way beer and cider are. As it ages, tannins join into larger pieces and fall as sediment, so an older bottle may have a deposit. To decant is to pour the wine off gently and leave the sediment behind.

Balance, sweetness and faults

A good wine balances alcohol, acid, sweetness, fruit and tannin so that none drowns the rest. A dry wine has little sugar left and does not taste sweet. Many people notice that sweeter wines keep longer once open: a lot of sugar pulls water out of microbes and kills them. Oak can add sweetness too; in 2017, scientists in Bordeaux found intensely sweet compounds that the wood releases during aging.

Too many esters or fusel alcohols count as a fault in wine. Other faults come from unwanted microbes.

Wine faults.

What a spirit is

A distilled spirit is a drink whose alcohol has been raised above that of the brew it came from, by distilling. Any sugary fruit or syrup can be fermented and then distilled; grain and potatoes work too, for whiskey and vodka. Fruit is mashed as for wine or cider; grain is malted, milled and mashed as for beer.

Distilling

Ethanol boils at 78.4°C (173.12°F), below water at 100°C (212°F). Heat the brew, and the steam carries more alcohol than the liquid had. Cooled back to liquid, a first distillate is about 25% to 35% alcohol.

The pot still. The pot is filled 50% to 75% with mash, wine or beer and closed. Thick mashes are thinned with 20% water. Most stills are copper, because copper binds sulfur compounds and gives a cleaner spirit. Distillers split the run into three parts: the head (fore-run), the heart (middle run) and the tail (after-run). Methanol boils lower than ethanol, at about 65°C, and small aldehydes and esters lower still; fusel alcohols boil at 115°C to 140°C.

A fire straight under the pot can scorch a thick mash and is an explosion risk. Some whisky makers keep the wood fire for its flavor and stir the mash all the time with a rummager. Others heat with steam, a hot water jacket or electricity.

The column still. Mash enters near the top and runs down toward the heat. Its vapor rises through a stack of plates and leaves some of the heavier compounds at each one. A pot still works one batch at a time; a column still can run without stopping.

Aging and finishing

In the barrel, tannins, wood compounds and minerals dissolve into the spirit, and further reactions follow. Many barrels are charred inside, and some held wine first and pass on its flavor.

• Apple and cherry spirits and brandies do best with a short time in oak or steel.
• Kirsch (cherry) and plum spirits rest in closed glass or tanks somewhere warm.
• Single malt Scotch and Irish whiskeys must age at least 3 years, bourbon only in new barrels, and other whiskies usually in barrels that held sherry or other wine.
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• Tequila, rum, vodka, moonshine and gin can be sold unaged.
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• The farther north a spirit is made, the longer it tends to age.

Most distillates come off the still above 40% to 45% alcohol and are cut with water to make them drinkable. Some flavor compounds cloud the spirit, so distillers chill it to between 0°C and −10°C and filter out what drops. Bottling is simple. Rum, whisky, fruit spirits and wine brandy may not have flavorings or sweeteners added after distilling; whiskey may take plain caramel coloring, fruit spirits may not.

Kinds of spirits

Most spirits come from one of four things:

• grain, for whiskey and vodka
• grapes, for cognac and brandy
• molasses, for rum
• agave, for tequila
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• Whiskey is distilled from cereal grains and aged in barrels. Corn, barley, rye or wheat malt is mashed much as for beer, and the wort goes straight to the still. Each region makes it its own way.
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• Brandy is distilled wine.
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• Rum is distilled from sugar cane.
• Tequila is distilled from agave.
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• Eau de vie: a clear brandy made from fruit, fermented, then distilled twice, and never sweetened. Framboise is the raspberry one. Similar drinks include pálinka from Hungary, raki from Turkey, coconut arrack from Sri Lanka, and Kirschwasser and Schnapps from Germany.
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Liqueurs are neutral spirit, usually something like vodka, flavored with fruit, herbs or nuts and often heavily sweetened. They are drunk straight, often with dessert, or go into coffee, cocktails and cooking.

Common liqueurs.