Originally By Tony Ackland
LactoseWal writes ...
Airag is fermented horse milk, a frothy, thick, alcoholic milk (about 3%a.b.v.) that fueled Genghis Khan's warriors and still remains a local favorite today. Mongols who like airag will drink up to 20 litres in a single day. It can be distilled to produce arkhi with an alcoholic content of about 12%. A Chinese style still is used. It is basically a pot with a wok filled with water over it, acting as the condenser, with the condensed alcohol on the underside of the wok dripping into a centrally placed ceramic jar. These days cheap vodka is readily available. Mare's milk is not readily available, so I have thought of using milk whey powder (75% lactose), and the lactose fermenting yeast kluyveromyces marxianus. 1.5kg of whey powder/5l water would be equivalent to 1kg of sucrose/5l water.
Lactose accumulates an estimated 1.2 million tonnes annually as a by product of the dairy industry. Lactose is a disaccharide like sucrose, and it can be converted to its monosaccharide components, glucose and galactose by acid or enzyme hydrolysis. 100g of lactose will produce 50g each of glucose and galactose. The lactose converting enzyme is also sold to people who cannot digest lactose in milk products. For the distiller unfortunately, converting the lactose won't work very well, as wine and beer yeasts will ferment the glucose, but for some genetical reason not the galactose when the two are combined. Even separately, galactose is fermented slowly. So using the lactose fermenting yeast, kluyveromyces marxianus is the way to go.
Milk whey is about 4.8% lactose
Milk whey powder is about 75% lactose
Concentrate your whey by boiling. You use your fermenter as a water distillation unit to get distilled water and a concentrated whey of say 25% lactose which you could ferment using kluyveromyces marxianus - you get 12% alcohol.
I thought of using lactase. Lactase enzyme can convert lactose to glucose and galactose, which is fermentable by ordinary wine/beer yeast but unfortunately because of genetics, when the two are together you get a poor fermentation.
You could I suppose also first ferment your 5% lactose whey using kluyveromyces marxianus, and then add sugar (1 kg/5l) and a saccharomyces yeast to ferment the sucrose. Whey contains a lot of soluble proteins and minerals which are a source of nutrients for the yeasts. This uses the whey as a source of water and nutrients. Note, this is a theoretical proposal.
The Golden Cheese Company of California also makes alcohol from its whey after removing the protein. See: http://ourworld.compuserve.com/homepages/gccc/alcoholp.htm
Utilization of Whey Through Fermentations
From "Alcohol from Whey" ... "First, the whey must be concentrated: that is, some of the water is removed. This is done by a process called reverse osmosis,....Then the protein in the whey is separated out (precipitated and filtered)....What is left is chiefly a mixture of water, the milk sugars and some minerals. By conventional fermentation technology, the sugars are converted into alcohol,....from which it can be recoverd by distillation."
For those in New Zealand, Anchor Ethanol was the first company in the Southern Hemisphere to manufacture alcohol from casein whey on a commercial basis.