Originally By Tony Ackland
RiceJack experiments again ...
'Sake World' http://www.sake-world.com Click on 'How Sake is Made'
'Ingredients of Japanese Sake' http://www.media-akita.or.jp/akita-sake/materialE.html
'The Chemistry of Sake Brewing' http://brewery.org/library/sake/techpa15.htm Click on 'Top' to go to the Index
'Production of Shochu Spirit from Crushed Rice by Non-Cooking Fermentation' http://ss.jircas.affrc.go.jp/engpage/jarq/33-1/nishimura/nishimura.html
A Japanese experiment by Kenryo Nishimura and others proved that it is not necessary to cook (to gelatinize) or convert (malting) milled grain prior to fermentation. Milling, soaking, adding enzymes and citric acid is sufficient - "....the product obtained by the non-cooking fermentation method was superior to that obtained by the cooking fermentation method in terms of both aroma and flavor components." The product referred to is 'shochu', a Japanese distilled spirit from rice. The non-cooking fermentation did take only one day longer than the cooking method due to the initial concentration of glucose in the cooking method. The method eliminates the messy cooking part of using grain and should encourage more to try grain-based washes. Here is a suggested quick moonshine mash for 5 US gals or 20 litres:
5 kg (10 lb) crushed grain (grits)
2 and 1/2 kg (5 lb) sugar
20 L (5 US gals) water
2 tbsp acid (2 g acid/litre)- a pH 4-5 is required.
2 tsp amylase enzymes (alpha-, beta-, gluco-) or 750 g (1 and 1/2 lb)
crushed malted barley grain (15% by weight)
Suitable ale yeast
Yeast nutrient (D.A.P.)
This should produce about 10-12%abv.
No pre-soaking of the crushed grain is required as there is sufficient sugars for the yeast to begin the fermentation process while the grain soaks.
Koji comes in two forms. First is koji kin, in other words, seed koji. This is generally in the form of rice grains on which the mould has been allowed to run rampant and go to spore and then dried. This is now the inoculum.
The second form is what is more commonly referred to as simply koji, but to distinguish it from koji kin is referred to as kome koji (kome means rice in Japanese--it is pronounced as two syllables, the "o" should be as in of, and the "e" as in egg.) So this koji is steamed and cooled rice that has been inocculated with some koji kin and then incubated at 30 to 35 degrees for a few days. The mould hyphae grow right through the rice. You need to stir it every 6 to 12 hours and stop it by bunging it in the fridge if it starts to go yellowy green--that means it is trying to form spore. In Japan, it is possible to pop down to the local supermarket and buy koji in this form fromm the cool-goods section as it is used for making miso paste and a few other food-related things.
In sake making, it is this kome koji that is mixed together with a larger quantity of steamed rice, some water and yeast to get the fermentation underway. At coolish temperatures (10-15 deg) the koji chugs away making amylase, the amylase converts the rice starch to sugar, and the yeast does what yeast does best. And yadda yadda yadda, eventually you get sake.