522 



NATURE 



[Sept. 12, 1878 



made by De Bary, and afterwards confirmed by Rees 

 and by Fitz, that alcoholic fermentation can be effected 

 by the growth of a species of Mncor, I am induced to 

 give an account of a visit made, in company with some 

 scientific friends, to the sakd breweries situated about 

 thirty miles away from Toki6, the capital of Japan. 



Sakd is the general name given to the alcoholic liquid 

 prepared by the fermentation of rice. There are many 

 varieties of it prepared in different parts of Japan, each 

 receiving some special name, either derived from the 

 district in which it is prepared, or from some fancy of 

 the manufacturer. It is a clear liquid, of a colour vary- 

 ing from the palest yellow to that of the darkest sherry, 

 and containing from twelve to fifteen per cent, by weight 

 of alcohol. There are some special kinds which contain 

 much less alcohol — from four to five per cent — but they 

 do not form the usual drink of the Japanese. It is almost 

 always served hot, being placed in porcelain bottles, 

 which are immersed in hot water and left there until the 

 whole has attained the proper temperature. 



This liquid is prepared on the large scale only in cer- 

 tain parts of the country, the most famous district being 

 that near Ozaka, one of the Treaty Ports. It is, how- 

 ever, often prepared on the small scale in private houses. 

 The winter is the only season during which brewing 

 operations are conducted, but this is not because the 

 fermentation temperature is to be kept low as in the 

 Bavarian method, but, I believe, in order to prevent the 

 action becoming too tumultuous, for the temperature of 

 fermentation is, in reality, even higher than that adopted in 

 England. But, from the fact that the largest breweries 

 are situated nearly 400 miles from Tokio, and the opera- 

 tions being carried on during a period when the Univer- 

 sity session is at its height, I have been compelled to 

 confine my inquiries to the smaller breweries at Hachioji, 

 near this city. 



The main room consists of a large wooden building 

 about 120 feet long by 50 feet broad, and 25 to 30 feet 

 high, running along the middle of which, in the direction 

 of its length, is a platform about 1 2 feet from the ground, 

 upon which some of the preliminary operations are carried 

 out. Upon this a number of wooden tubs are placed, 

 which serve for the preparation of the ferment, an opera- 

 tion which requires to be repeated several times during 

 the brewing season. On the ground, ranged along the 

 two long sides of the building are large tuns used for the 

 storing of the sakd when made, and some of which are 

 also used for the actual processes of fermentation. 



The brewing commences with the preparation of the 

 ferment. For this purpose at the end of the previous 

 brewing season a quantity of a green mould is produced 

 upon rice by exposing steamed rice mixed with a certain 

 proportion of the ash of some tree, and over which the 

 spores of this fungus have been scattered in a well-closed 

 chamber, which I may term the "fungus-chamber." This 

 is a small room about 7 ft. high by 6 ft. broad, and 8 ft. 

 long, well lined and covered with straw and matting, 

 so that its high temperature may be kept up for a con- 

 siderable time. In this chamber the rice and spores are 

 left for about ten days, the atmosphere being kept quite 

 moist by the vapour given off from the steamed rice, and 

 at the end of that time the grains are found to be covered 

 with a green fungus full of spores, and apparently the 

 same kind as is found growing upon putrefying organic 

 substances. The temperature of the chamber when 

 examined was 25° C, that of the external atmosphere 

 being 13° C. This product is called, in Japanese, tane or 

 seed. 



When prepared at the end of the season it is preserved 

 until the next by being placed in bags, and inclosed in 

 wooden boxes between layers of a mixture of equal parts 

 of lime and wood- ashes. 



When it is required to commence operations, a similar 

 method is adopted to that just described, that is, a quantity 



of steamed rice is placed on wooden trays in the " fungus- 

 chamber," but not mixed with any wood-ashes, and then 

 tdn^ (spores) is scattered over it, and the chamber kept 

 closed for a period varying from two to four days. At 

 the end of this time the rice-grains are found to be 

 covered with large quantities of fine hair-like threads, the 

 mycelium of the fungus added. In this state it is called 

 "koji." 



If this were left for a longer period in the fungus- 

 chamber, it would produce spores, and the brewer calls it 

 " the friend of tane," but in order to carry on the deve- 

 lopment of the mycelium most vigorously, it is necessary 

 to use wood-ash in addition, which thus seems to act as a 

 fertiliser. 



Having thus obtained the "koji," or mycelium, the 

 brewer uses it for effecting the preparation of his yeast. 

 For this purpose he mixes steamed rice with 30 per cent, 

 of its weight of " koji " and a sufficient quantity of water 

 to make a thick mud, in small shallow wooden tubs, 

 which are kept on the platform previously mentioned. In 

 these it is frequently stirred and rubbed round with 

 wooden tools, during a period of about ten days, in the 

 course of which the grains of rice appear to be broken 

 down, and the whole assumes a much thinner consistence, 

 while at the same time the liquor becomes decidedly 

 sweet. This is a change which is anything but clear ; it 

 would seem that it is connected with the development of 

 an organism derived from the "koji ;" as on the small 

 scale, I have noticed the production of minute cells, 

 apparently budding, but whether they have any connec- 

 tion with the air-fungus, the mycelium of which covers the 

 rice in "koji;" or whether they have been developed 

 from germs accidentally present in the " koji," I am not 

 able to say, though I hope that further experiments will 

 make this point clear. 



After the end of the ten days this product is mixed with 

 fresh-steamed rice, water, and "koji," and introduced 

 into larger wooden vessels, in which the mixture is 

 heated by means of closed wooden tubs, containing hot 

 water, and in order to prevent too rapid radiation, 

 the whole is covered with matting. The hot-water tubs 

 are replaced day by day, so that the temperature is kept 

 up for a period varying from eight to thirteen days. The 

 average temperature seems to be about 35° C. (95° F.). 

 During this time there is a continuous development of 

 gas, and a scum gradually forms upon the surface until 

 it has a thickness of a little more than one inch, and, 

 when examined under the microscope, presents the usual 

 appearance of brewer' s ferment — saccharomyces. At the 

 end of this stage, if the operation has been well con- 

 ducted, five tastes are to be distinguished : sweet, bitter, 

 astringent, alcoholic, and sour ; but of these five, all of 

 which are quite distinct, the bitter, astringent, and sour 

 tastes are most marked. The product of this operation 

 is called "moto," which means "source" or "origin," 

 referring to the fact that it is from this ferment that the 

 sakd is subsequently formed. All the previous part of 

 the brewing process has thus had for its object merely 

 the preparation of the yeast, but it is certainly the most 

 interesting, from the obscurity which surrounds it. 



The actual fermentation is divided into three stages, 

 called respectively beginning, middle, and end, the pro- 

 portions of steamed rice and ferment varying slightly 

 in each stage, but giving a final result of 100 parts of 

 steamed rice to 30 parts of ferment. This mixture, 

 together with the proper quantity of water, is placed in 

 one of the large tuns before mentioned, and allowed to 

 remain for about fifteen days in all, during which time 

 fermentation actively proceeds, and the liquid becomes 

 strongly alcoholic, at the end of which time it is drawn 

 off from the grains of rice which have subsided, and 

 introduced into other tuns, where it is allowed to remain 

 to permit the remainder of the rice to be separated. The 

 residue is placed in bags and subjected to pressure in a 



