Ethanol content of Kefir Water
[Article in German PMID: 8204224 [PubMed - indexed for MEDLINE]
Rabl W, Liniger B, Sutter K, Sigrist T.
Institut fur Rechtsmedizin des Kantonsspitals St. Gallen.
The question of the influence of kefir on blood-alcohol-level has been asked in a legal proceeding. The questioned recipe consisted of 2 liters of water, 6 tablespoons of kefir granules (about 120 g), 150 g sugar, 2 figs and one lemon. The consumption took place after two days of fermentation. Experimentally we found, that one liter of this kefir product may contain up to 38 g/l ethanol after 7 to 10 days. On the second day we measured up to 16 g/l ethanol.
Note: The actual initial amount of grains used overall does not establish the level of potential alcohol. The amount or population of the yeast/bacteria contribute to the TIME and TEMPERATURE it takes to complete the ferment. In other words 1 tablespoon of grains will produce the same amount of alcohol as would 6 tablespoons of grains. The difference is that the 1-tablespoon will take longer to achieve.
If you take the Final Gravity Reading (FG) from the Initial Specific Gravity and minus the Total Acidity you’ll come close to the remaining alcohol level. The margin of error in these cases are high and will not hold up in any court. This is a good way to see how you process is working overall and gives you a comparable
Note: the amount of alcohol kefir may produce is limited first by the bacteria. There are 2 classes of Lactobacillus. Homeofermentative produces only Lactic Acid. and Heterofermentative produces lactic acid, alcohol and carbonation.
Yeasts airborne or otherwise generally do not dominate and have to compete with the bacteria for food and nutrients. With oxygen being available the yeast are more in Respiration and giving off more carbonation (CO2) than when no or little oxygen is available. With little oxygen available (anaerobic) the yeast go into Fermentation. They produce more alcohol than carbonation. The Heterofermentative bacteria will also produce higher percentage of alcohol in a anaerobic environment. If alcohol is a concern for you or your family, do not use an Airlock, or cap. Use a cloth or paper towel secured with a rubber band.
You may also want to consider Kombucha Tea. Kombucha is similar to all these Lacto-Soda's and the differences in taste and health may not be noticeable at all. Kombucha produces Gluconic Acid a key benefit where other ferments do not. Kombucha is a different bacteria. One of 4 subspecies of the Acetobacter, or acetic acid producing bacteria. Acetic acid is another proven beneficial acid. Vinegar is acetic acid. These bacteria convert alcohol into acetic acid in the presence of oxygen. That is the crucial alcohol level differences. Kombucha will always be lower in alcohol. Typically less than ½ of 1% in an aerobic ferment. However when bottled and in a Second Ferment without the presence of oxygen, Kombucha will produce higher levels typically in the 4-6% range.
The longer you ferment the greater the alcohol percentage. Many folks cap and bottle their ferment. If not refrigerated his will create higher levels of alcohol faster. To avoid increasing the alcohol but having lots of carbonation consider our uKeg64.