Experiments with Tibicos (Water Kefir)

Quince-honey tibi
Quince-honey tibi

When my friend Rose Marie first asked me what I knew about water kefir, I was baffled. Water kefir, she explained, was a culture for a bubbly beverage made from water, not milk, in the form of “grains” that resemble those that produce kefir.

I was skeptical. Was water kefir, like kombucha, another excuse to drink soda pop and call it good for you?

Well—yes, more or less. But I’ve since come to enjoy using what many Americans are now calling water kefir but that has gone by many other names in the past, including California bees, African bees, ale nuts, Balm of Gilead, beer bees, beer plant, and Japanese beer seeds. Europeans call water kefir tibi, and they maintain that it came originally from Mexico, where it is likewise called tibi or, traditionally, tibicos.1 In Mexico, grains of tibicos are fermented with pineapple juice or brown sugar (or both) in water to make tepache de tibicos, a refreshing, sweet, slightly alcoholic beverage.

Tibicos, or water kefir grains. The coloration on some of them resulted from using dark fruit syrups.
Tibicos, or water kefir grains. The coloration on some of them resulted from using dark fruit syrups.

Rose Marie ordered some of the grains from an online vendor and brought me about two tablespoons of them in a little plastic tub of water.2 I poked them; they were firm, irregularly shaped, colorless and translucent gelatinous masses, averaging about a quarter inch across. I fed them some sugar and put the tub in the refrigerator.

Within a day or two the lid was swelling. I needed to do something soon with my tibicos, I figured, or risk killing them. I could put them in a jar on the counter with more sugar water, but I wouldn’t want those empty calories, and why would they? Surely they would prefer to have some fruit juice. I didn’t have a pineapple handy, but it occurred to me that I had dozens of bottles of fruit syrups of various sorts, left over from candying fruits or made experimentally. On hot days my kids sometimes combined the syrups with carbonated water from the grocery store. I considered how I hated buying those plastic bottles, and hauling them back to town to recycle them.

I was beginning to see some value in tibi.

So I began making my own tibi pop. The recipe is simple:

Pour ½ to 3/4 cup fruit syrup, depending on the magnitude of your sweet tooth, into a quart jar. Add a tablespoon of tibicos and enough water to fill the jar. Fit a lid on loosely. Set the jar on the kitchen counter. Wait two days. Strain out the tibicos, rinse them, and store them in fresh sugar-water in the refrigerator. Funnel the partially fermented liquid into a liter-size clamp-topped bottle, the kind with a ceramic stopper that’s lined with a rubber ring. Clamp the bottle shut. Leave it on the counter for two days, no more. When you’re feeling hot and thirsty, unclamp the bottle. Gas should explode from the bottle just as if you’ve opened a bottle of champagne. If the explosion is weak, reclamp the bottle and wait another day or two. Then pour a glass of the bubbly. Adjust the taste if you like, with an ice cube or a squirt of lemon. Reclamp the bottle, and leave it on the counter. Pour yourself more tibi every day or two until the bottle is empty.

Each time you open the bottle, it will be as bubbly as before, or more so. I’ve made strawberry tibi, Asian pear tibi, plum tibi, and even tibi from syrup left from preserving green walnuts (the last tasted a bit like root beer). My only mistake was when I left the tibi bottled too long, perhaps four days, without releasing the pressure. Between opening the bottle and reaching the sink I managed to spray every wall and cupboard and several open cookbooks with plum pop.

If you don’t drink your tibi every day, do remember to open the bottle daily to release the pressure. If you forget one day, open the bottle the next day in the sink or outdoors. Ignore the example of one tibi maker, who, after a bottle of his tibi exploded, stood at a distance from the others and shot them with a rifle.

In an article published in 1990, Jürgen Reiss analyzed tibi scientifically. 3 The grains, he found, are made of dextran, a polysaccharide. Within the dextran are, in a symbiotic relationship, three species of microbes: Saccaromyces cerevisiae (which is used in making beer, wine, and bread), Lactobacillus brevis (common in sauerkraut and fermented pickles and a spoiler in beer), and Streptococcus lactis (also known as Lactococcus lactis, and used in making buttermilk and cheese). Reiss concocted his experimental tibi with dried figs and other dried fruit, as is common in Europe.

This is what happened in the fermenting tibi, according to Reiss: The sugar level declined constantly. After six days the alcohol reached its maximum level, slightly less than 0.5 percent, and acetic acid reached its maximum, too. Lactic acid was produced “in reasonable levels” only after fourteen days.

I can barely taste the acetic acid in my tibi, but I can’t miss the lactic acid. When it comes on, after about three weeks in my cool kitchen, the pop suddenly goes flat and sour. It is now vinagre de tibicos, which is drunk in Mexico to promote weight loss, fight arteriosclerosis, and prevent heart attacks. Only at this point does tibi seem truly comparable to kombucha, a weak vinegar made from a solution of refined sugar, flavored with tea, and usually drunk when partially fermented, so it’s at once sweet, sour, and slightly alcoholic. Both tibi and kombucha are considered probiotic, tibi because Lactobacillus brevis is said to survive in the gastrointestinal tract. Tibi is different from kombucha in that tibi is slow to sour and, when it does, the acid produced is mainly lactic, not acetic.

Tibi is also much gassier than kombucha, though not as gassy as commercial pop. As a child I never liked those sharp-tasting bubbles or the violent burps that followed. But with the gentler gassiness of tibi I’m learning to appreciate the taste of carbonation. Yes, carbonation has a taste! Only a few years ago, at the University of California, San Diego, scientists discovered that an enzyme expressed on the sour taste receptor cells in our mouths is stimulated by carbon dioxide.4  Humans have been enjoying this taste since at least the late Middle Ages, when bubbly mineral waters from natural springs became popular, medicinal refreshments. Ginger beer, made from another set of bacteria in natural symbiosis, originated in England in the mid-eighteenth century (you can buy ginger beer “plant” as well as tibicos from online sources). Europe’s great appetite for both mineral and bacterial bubbly waters caused Joseph Priestly to believe he’d made a great discovery when he invented the first artificially carbonated water in 1767. Soon English and American pharmacists were combining carbonated water with syrups to produce our modern soda pop. Until well into the twentieth century, people believed that carbonated water of any sort, syrupy or not, would cure or ease all sorts of ailments.

I wasn’t fooled, though. I was drinking pop without dyes or artificial flavorings or colorings, pop that might please the bugs in my bowels, pop that didn’t require buying or recycling a nasty plastic bottle, but still I was drinking pop. Could I make it a little more healthful? I eyed the quince in honey syrup on my kitchen counter. This was March, and the jar had sat there since early December. I make quince-honey syrup every year by simply mixing a pound of cubed quince with a pint of honey (this and many other syrup recipes are in The Joy of Jams, Jellies, and Other Sweet Preserves). The honey draws water out of the quince pieces, which slowly shrivel, and soon I have 2 ½ cups of raw syrup, rich with vitamin C from the quince and aromatics from both the quince and the honey, ready to soothe any sore throat that arises.

Straining quince syrup
Straining quince syrup

We’d had no sore throats over the winter, and now spring had almost arrived. It was time to strain that syrup, revive the shriveled quince cubes by simmering them in white wine, and make myself some quince-honey tibi.

The tibicos seemed to respond to the honey as well and as fast as they did to refined sugar. The drink turned out a little foamier than usual (honey causes foaming when used in jam making, too). It tasted strongly of both quince and honey. The quince-honey tibi was especially delicious after a week, when it was less sweet and noticeably, though barely, alcoholic.

Not olive oil but quince-honey tibi
Not olive oil but quince-honey tibi

At this point I value my tibicos enough to want to share them. Sadly, they haven’t multipled noticeably; I still have only about two tablespoons. Rose Marie said ginger seemed to encourage tibicos to reproduce, but mine didn’t respond when I put a couple of slices of ginger in their refrigerator tub. In Jürgen Reiss’s experiments, he found that tibicos reproduced themselves when fed dry figs but not when given other dry fruits (raisins, dates, prunes).

In my pantry I have dried Desert King figs in plenty. My next batch of tibi, I think, will be fig-flavored—perhaps with a little ginger added, too. After that, I’ll have to try a Mexican-style batch, with pineapple. I don’t need to buy a pineapple, actually. As I now recall, there’s a bottle of pineapple syrup in my pantry.

1. The best source of information I’ve found on tibicos in Mexico is Más Allá de Pulque y el Tepache: Las Bebidas Alcohólicas no Destiladas Indígenas de México, by Augusto Godoy, Teófilo Herrera, and Miguel Ulloa (México City: Universidad Nacional Autónoma de México, 2003). As far as I can find, the book is unavailable in any U.S. library or bookstore, but most of the discussion can be read on Google Books. According to this book and other sources, tibicos develop on the fruits and pads of nopal cactus, which may be the original, ancient source of the grains.

2. Online sources for tibidos include www.yemoos.com and www.waterkefirgrains.com.

3. “Metabolic Activity of Tibi Grains,” in Zeitschrift für Lebensmittel-Untersuchung und Forschung 191:462­–65.

4. Jayaram Chandrashekar et al., “The Taste of Carbonation,” in Science 16 (October 2009): 443-45.

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Honey from a Watermelon

I didn’t invent watermelon molasses, Sara Bir informed me. At least I wasn’t the first to invent it.

I’d cooked twenty pounds of watermelon into a cup of syrup because I and the rest of the family were tired of eating watermelon and the melon was overripe anyway. Besides, I’d had grape molasses (arrope, mostillo, mostarda, saba, pekmez) on my mind. I’d been thinking about life before cheap cane sugar, especially in Europe. Honey was a cherished sweetener then, but it wasn’t always available. Before the word molasses and its cognates referred to cane syrup, they were applied to honey-like fruit or vegetable syrups. Molasses derives from the Latin word for “must”—grape juice—and the word for “must” comes from the Latin word for “honey.” The oldest reference to molasses in the Oxford English Dictionary, from 1582, defines it as “a certeine kinde of Sugar made of Palmes or Date trees”; the second, from 1588, calls it “Sirrope of sugar, beanes [etc.].” When you had more fruit—even beans!—than you could eat, you might preserve its essence by boiling down the juice.

Fruit molasses hasn’t gone entirely out of style. Grape molasses, fig molasses, and pomegranate molasses are still imported to the United States from the Mediterranean region and sold at high prices in specialty stores. These products provide a mellow sweetening in sauces, dressings, and desserts, and grape molasses is the sweetener in cheaper kinds of balsamic vinegar.

Why not make molasses from watermelon? I’d decided to try it. The result, as I described in The Joy of Jams, Jellies, and Other Sweet Preserves, was remarkably like grape molasses. With so much boiling, fruit juice darkens and loses its volatile flavors. In the finished syrup, you taste mostly sweetness and minerals.

When Sara came upon my recipe for watermelon molasses, she’d already made a version herself—an experience she describes in entertaining detail at www.metroactive.com/papers/sonoma/09.04.03/dining-0336.html. Sara had come upon a little cookbook, Our Favorite Recipes, compiled by the Friendly Aid Society of Free Evangelical Lutheran Cross Church of Fresno, California, and published in 1979. In the book were some distinctly American dishes, such as Jello salads, but there were also foods with exotic-sounding names, like grebbles and berrocks. What interested Sara most were the three coffeecake recipes calling for watermelon molasses, and the recipe for watermelon molasses itself.

Sara wrote me to ask what I knew about watermelon molasses. I didn’t know much; I certainly didn’t know it was a popular ingredient in the kitchens of Fresno Lutherans. I wondered where these people had come from. I pondered the word berrocks, which didn’t sound as if it had ever been German.

On the Web, I found numerous recipes for bierocks—yeast buns stuffed with ground beef and cabbage—and at least one was attributed to the Volga Germans. These were people from southwest Germany, mostly, who at the invitation of Catherine the Great in 1763 settled along the Volga River in Russia, where they were allowed to maintain their language, culture, and various religious traditions (Lutheran, Catholic, Reformed, and Mennonite; Jews weren’t welcome). Although the Volga Germans mainly kept to themselves, they must have learned a few things from the locals. Their bierocks or berrocks—the accent is on the second syllable—were pirogi.

A century after the Germans began migrating to Russia, they lost some of their special privileges, including exemption from military service. When other countries beckoned new settlers, whole Volga villages moved themselves to North and South America. In 1886 and 1887, I discovered, Evangelical Lutherans from several villages on the eastern side of the Volga, near Saratov, settled in Fresno County.

Fresno is a good place to grow watermelons. So is the Lower Volga, a Russian culinary dictionary assured me. Watermelons grow so abundantly from Kamyshin to Astrakhan, on the Caspian Sea, that until recently much of the crop was either brined or boiled into nardek—watermelon molasses! Modern transport allows the shipping of fresh watermelon today, so nardek is produced in only small amounts. It’s a lot of trouble to make, after all, and refined sugar is cheap. For Fresno Lutherans, however, the tradition lives on, or at least it was still alive in 1979. Nearly a century after their ancestors had come to Fresno from Russia, the Friendly Aid Society members still required watermelon molasses to make a proper coffeecake.

The Friendly Aid Society members called their watermelon molasses by the English name, the same one I used. But I thank Sara for sending me on the trail of an old word—nardek—for my invention that truly wasn’t new at all.