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.
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.
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.
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.
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.