The Drunken Botanist: The Plants that Create the World's Great Drinks (50 page)

Senegalia senegal
(syn.
Acacia senegal
)

fabaceae (bean family)

A
small, prickly tree that grows in the Sudanese desert has been responsible for such diverse duties as keeping newspaper ink on the page, preserving Egyptian mummies, and stabilizing the sugar and color in soft drinks. It is also the key ingredient in old-fashioned
gomme
syrup, where it adds a smooth, silky texture to cocktails and keeps the sugar from crystallizing.

There were, until recently, over a thousand species of trees classified as acacias, almost all of them coming from Australia. A few are native to warmer areas of Europe, Asia, Africa, and North and South America. But taxonomists recently split the acacias into several different genera, a decision that was so controversial that petitions were circulated, botanists were sniping at one another publicly, and accusations of greed and corruption were flung at scientists during the normally staid conference on botanical nomenclature. As a result of their reorganization of the acacia genus, Sudanese farmers no longer grow acacias; they now grow
Senegalia senegal.
Acacia gum, also called gum arabic, will presumably have to find another name as well.

The botanical debate is not the only controversy surrounding the tree. Because it grows in Sudan, it is at the center of a brutal war. Supplies of the raw gum—which is harvested by scraping the tree and hand-collecting the globs of gum that issue forth—have been threatened by fighting in the region. The U.S. State Department issued warnings in 1997 about the possibility that Osama bin Laden had invested heavily in the Gum Arabic Company, a government-controlled monopoly that exported the gum to Europe for processing. The company denied ties to the terrorist. After heavy lobbying from the soft drink industry, the economic sanctions imposed on Sudan were amended to grant an exemption for gum arabic.

Another threat to the tree is climate change: as drought conditions worsen, it is confined to an ever-smaller belt across Sudan. Agricultural aid workers are trying to expand the tree's habitat and teach farmers how to grow “gum gardens” using special water catchment techniques that help the trees survive on minimal rainfall and produce enough gum to support a family. The farmers also contend with plagues of locusts, termites, fungal diseases, and ravenous goats and camels.

This twenty-foot-tall tree puts down a taproot one hundred feet long, which explains its ability to survive tough desert conditions. The tiny leaves help prevent water loss, and the canopy's expansive umbrella shape gives those leaves maximum exposure to sunlight to make up for their size. The sweet, sticky gum also serves a purpose to the tree, healing wounds, protecting against insect damage, and fighting disease.

By about 2000 BC, Egyptians had learned that scraping the tree's bark would put it under stress and force it to produce more gum. They used it to make ink, mixed it into food, and employed it as a binding paste for mummification. (The old French word
gomme
comes from older words for gum, the Egyptian
komi
and Greek
komme.
) The gum has been in continuous use as a binder in inks, paints, and other products of industry and as a thickener and emulsifier for medicinal syrups, pastes, and lozenges. Bakers used it in ice cream, candies, and icing, and it was only a matter of time before the sweet
sirop de gomme
became a useful cocktail ingredient as well. It adds a silky texture that is impossible to replicate with simple syrup.

Gum arabic has returned as an ingredient in specialty cocktail syrups, but it's also easy to mix up a batch at home. Buy food-grade gum arabic from spice stores or shops catering to bakers and confectioners. (Gum arabic sold in craft stores is a lesser grade intended for use in art projects.)

SPRUCE

Picea
spp.

pinaceae (pine family)

T
he fact that a vitamin C deficiency caused scurvy was not entirely understood until the 1930s, but ship captains had, from time to time, managed to prevent the disease by stocking up on lemons and limes before leaving on a long voyage. And when citrus wasn't available, they unknowingly substituted other sources of vitamin C—including the young, green tips of spruce trees.

Captain James Cook tried a recipe on his crew that he had obtained from the botanist Joseph Banks. The recipe consisted of spruce twigs boiled in water with some tea to improve the flavor, which would then be combined with molasses and a bit of beer or yeast to start the fermentation. Cook wrote in his journal that either berries or spruce beer cured the crew of scurvy.

Spruce beer was well known to Jane Austen, who wrote to her sister Cassandra in 1809 about brewing a “great cask” of it. A pivotal moment in
Emma
even revolves around a recipe for spruce beer, with Mr. Knightley offering the recipe to Mr. Elton, who borrows a pencil from Emma to write it down. In a classic Austen plot twist that would prove important later, her friend Harriet stole the pencil Mr. Elton used to write down the ingredients as a remembrance of him.

Recipes for spruce beer were abundant in eighteenth-and nineteenth-century journals. Benjamin Franklin is widely credited with creating a recipe for the beer—but it wasn't his invention. While he was ambassador to France, he copied several recipes from a cookbook called
The Art of Cookery Made Plain and Easy,
written by a woman named Hannah Glasse in 1747. (Glasse, by the way, wrote a number of interesting recipes Franklin missed, including one called Hysterical Water that included parsnips, peony, mistletoe, myrrh, and dried millipedes, soaked in brandy and “sweetened to your taste.”) He never meant to take credit for her recipe; he simply
copied it for his personal use. Nonetheless, it was found among his papers, and the story that one of the Founding Fathers created a recipe for spruce beer was too good to resist. Modern re-creations of the recipe credit him alone, not Hannah Glasse.

Spruce trees are ancient creatures, dating to the late Jurassic period, 150 million years ago. There are as many as thirty-nine species, depending on which botanist you ask, and they are distributed across colder climates in Asia, Europe, and North America. Like many conifers, the trees grow slowly and, if left unmolested by chainsaws, live to an astonishing old age. The world's oldest living tree is a Norway spruce with a root system that dates back 9,950 years.

The trees produce ascorbic acid, and other nutrients that help fight scurvy and enhance uptake of vitamin C, as a defense mechanism in winter to help them survive the cold and develop seed cones. Highest levels of the vitamin are found in the red and black spruce (
P. rubens
and
P. mariana
), but the FDA has approved only black spruce and the white spruce,
P. glauca,
as safe natural food additives. To the untrained eye, spruce trees can resemble other, highly poisonous conifers such as the yew, so home brewers are advised to get expert advice before harvesting in the forest.

SUGAR MAPLE

Acer saccharum

aceraceae (maple family)

I
n 1790, Thomas Jefferson bought fifty pounds of maple sugar to sweeten his coffee. This was less a culinary decision than a political one: he'd been pressured by his friend and fellow signer of the Declaration of Independence, Dr. Benjamin Rush, to advocate for the use of home-grown maple sugar instead of cane sugar, which was dependent upon slave labor.

Although he was a slave owner himself, Jefferson nonetheless saw the wisdom behind this idea. He wrote to a friend, British diplomat Benjamin Vaughan, that large swaths of the United States were “covered with the sugar maple, as heavily as can be conceived,” and that the harvesting of maple sugar required “no other labor than what the women and girls can bestow . . . What a blessing to substitute a sugar which requires only the labor of children, for that which is said to render the slavery of the blacks necessary.”