That Crazy (or not so Crazy) Koji Corn Whisky

[6/15/24, I wrote one draft of this many years ago and never looked back. Supposedly it has launched some ships.]

Follow along: IG @birectifier

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My introduction to the idea of Koji process whiskies came from an awesome reader who sends me great papers he finds. It is a whopper of a story complete with a secret efficient production technique, monopoly ambitions, horrible anti-competitive behavior, and a little bit of mobster strong arming. That was the turn of the century (maybe) and it didn’t pop up again until the 1960’s research I just put out in American Whiskey by the Numbers. Only one distillery, no. 40, was making a corn whiskey with the process and they didn’t make any other kinds of mashes unless they also produced neutral spirits that might have escaped the report.

So, the eccentric seeming process survived! But is there anymore to the story? Was it ever a fad way back when? Do we see it by degrees in anyway today (exogenous enzymes)? Was it ever used in a fine context or was it only relegated to commodity junk?

To start, the idea is widely known, and could be said to be a home distillers fad (bean0), but probably not connected to its root history. Quite possibly the lineage of the idea was broken and brilliant home distillers quickly reinvented the old wheel.

Three papers have turned up and it is important to throw them on the easily searchable historic record returning it to people so they can understand and contextual what they are doing, not doing, or if they are a Momofuku devotee, naturally what their next business venture will be.

The first paper comes to use from Dr. Jokichi Takamine himself in 1914 from The Journal of Industrial and Engineering Chemistry.

Enzymes of Aspergillus Oryzae and the Application of its Amyloclastic Enzyme to the Fermentation Industry.

This article is very cool and very readable adding to our timeline of the processes’ beginning. He does not betray his mobster monopolists or possibly this is where he was recruited.

Takamine defines Taka-Koji (named after himself!) and differentiates it from Japanese Koji which implies a culture grown on steamed rice. He also brands an extract of Taka-Koji Taka-diastase.

This article actually is kind of awesome and I wish more papers were written with his tone and style. Takamine encounters failure, reflects and then returns to repeat experiments with new ideas. He even constructs an apparatus from a mason jar and a clock mechanism to revolve it like a drum! Hence the drum technique.

I don’t want to take away Takamine’s voice, but he notes (and at length quotes) a Hiram Walker collaborator duplicating his work in Canada and presenting his findings to the Congress of Applied Chemistry so this idea was no quiet fringe finding. It is a great summary and I like it because it explains how they conducted their first experiments. This may help and inspire a small distillery to give it a one batch go for a special barrel.

“On account of the numerous great variations in the price of barley malt (in two consecutive years the price varied 100 per cent), it would be of great value to the distilling industry if a converting medium of moderate and more uniform price could be employed instead of barley malt. Eliminating, therefore, the different grains as a source of converting medium, I turned to the diastase produced by a microorganism, the Aspergillus oryzae. Takamine was the first to introduce the Koji process in America. As far back as 1889 he advocated the use of Koji in the distilling industry. Instead of growing the fungus on rice, Takamine employed a material far cheaper for this country, namely, wheat bran. An extract of the wheat bran, on which the Aspergillus oryzae had been allowed to germinate, contained the diastase, produced by the Aspergillus, and this extract was mixed with the mashed grain, bringing about the conversion of the starchy materials. Lately, I understand, he has succeeded in adapting a modification of the Galland-Henning malt drum system to his process. This should be a great improvement over the old floor system, in so far as it makes it possible to work under absolutely sterile conditions. For my experiments I decided to use the Taka-Koji itself instead of the diastatic extraction of same and add it to the mash in the same way as malt. Before beginning the practical experiments in the distillery, laboratory experiments were conducted on a small scale to ascertain the amount of Taka-Koji which was necessary to convert a certain amount of starch into sugar, and also the optimum temperature at which to conduct the conversion. It was found that 4 g. of Taka-Koji was sufficient to give a complete conversion in a mash made from 96 g. of corn and rye, the corn containing 15.o per cent of moisture and the rye 14.0 per cent. Three experiments were made in the distillery. For the first experiment only a 14 gallon can was used and a portion of our ordinary mash from the mashtub was employed, the mash being taken from the main mash just before malt was going to be added for conversion. The second experiment was performed on a somewhat larger scale. Instead of using mash material from the mashtub, the mash was made separately. It consisted of 500 kg. altogether, of which 20 kg. were Taka-Koji. The third experiment was performed on a good-sized working scale. Two mashes, each consisting of 3,401.94 kg. (of which 131.j kg. were Taka-Koji), were prepared. The two mashes were filled in Turn No. 25 of Friday, May 26, 1911. Turn No. 25 was distilled separately and the yield was 36 liters of 100 per cent alcohol per 100 kg. of mash material, just a trifle higher than the yield of the other mashes which were made the same day. In judging the adaptability of Taka-Koji for use in distilleries several questions must be asked and answered:
“Is Taka-Koji capable of giving a complete conversion of the starchy materials in the mash?
“Yes, 4 per cent of the air-dried Taka-Koji will in 15 to 20 minutes give a complete conversion of well prepared mash material.
“Is the fermentation a satisfactory one?
“While it is accompanied by a strong odor, which is prevalent in the fermenting room, the fermentation, however, is very rapid and complete, and on this account should give rise to the least amount of infection.
“Is the yield of spirit satisfactory?
“Yes, the yield obtained was a little higher than the yield gotten from the barley malt mashes, although the total fermentable extract available in the mash material was less. The yield of 36 liters of 100 per cent alcohol per 100 kg. of mash material is of course only a comparative yield. In distilleries which employ cookers and boil the corn under pressure, a higher yield would naturally result.
“Therefore, I should say as a final conclusion that in distilleries which make commercial or potable neutral spirit, the Taka-Koji process could be introduced to advantage. Aside from a probable higher yield in spirit, the saving in malt bill would be worth while in years with normal malt prices and very considerable in years when the malt prices become abnormal.”

Questions arise immediately. Is the aroma pleasurable or the product of ordinary off-aromas? Would the aroma have a market now that we live in a world of mezcal and funky rum fetishes? Who knows, but more importantly who is qualified to find out? I want to drink it, but the discovery may have been colossally important to the product of industrial and fuel ethanol. I hope Takamine lived long enough to profit and see the fruits of his labor.

The next paper is from 1939. Saccharification of Starchy Grain Mashes for the Alcoholic Fermentation Industry: Use of Mold Amylase.

This paper is kind of cool to breeze through. First we learn:

The authors prefer to use the term “amylase” since it avoids confusion that sometimes results from the fact that “diastase” is the French term for enzyme.

Then we learn more of where the Takamine-H. Walker experiments ended up.

Use of mold preparations to replace malt in the fermentation industry was suggested by Takamine, and large-scale tests at the plant of Hiram Walker and Sons, Inc., in Canada in 1913 (9) proved entirely successful, yields of alcohol being better than with malt. However, a slight off-flavor or odor was produced in the alcohol, and since the flavor is of paramount importance in beverage alcohol, Takamine’s preparation has not found favor in the alcohol industry, Now, however, with the increasing interest in power alcohol, it would seem that a procedure similar to Takamine’s should hold much promise for production of industrial alcohol.

They go on to imply the Hiram Walkers process was private and with interest in industrial alcohol it would be beneficial to experiment and make a publicly known process available. We used to see more of this publicly funded research aimed at aiding private enterprise and generating competition. The acknowledgements at the end do imply a private grant.

What I want to know is what were these aromas like? Reminiscent of baijiu? Sweaty feet and bubble gum? Are any home distillers coming to an off/aroma-negative conclusion or is it avoided if an extract of the enzyme is separated from the moldy bran?

Their experiments gets into finer details and provides best bets for anyone wanting to play along. They do not return to the subject of the aroma because they are interested in non-potable alcohol. Their bibliography has a bunch of Dr. Takamine’s patents which go back as far as 1894.

The third paper is from 1949 and also published in the Industrial and Engineering Chemistry journal (which has published lots of other great works on beverage distillation). The research was conducted at the Northern Regional Research Laboratory, Peoria, Ill.

Grain Alcohol Fermentations: Submerged Mold Amylase as a Saccharifying Agent.

First off we should note that Peoria was home of distillery no. 40! The introduction makes it seem like they are doing some reinventing of the wheel or duplication of the 1939 experiments and the 1939 paper is in their bibliography but for some reason listed as 1940. The addition here might be the exploration and comparison of an “amylo process”. It is acknowledged that the processes have been already used commercially. Hiram Walker and Sons, Inc, Peoria, Ill and E.R. Squibb and Sons, Inc. New Brunswick N.J. are noted in foot notes. I basically skimmed to the end and found no mention of aroma nor whisky.

To sum it up. Koji is in culinary vogue, but is anything cool and promising happening here? Probably not. Does this have any impact on Bourbon as we know it? Commodity American whiskey may or may not have used percentages of industrial enzymes. I’ve heard murmurs but never read anything specific. I’ll have to keep an ear to the ground. If you know anything specific with a reference, do send it in. Fine American whiskeys likely do not flirt with industrial enzymes. One long shot idea to consider is that ethyl carbamate, a regulated congener comes from malt (among other things). To reduce it under a threshold for trade purposes (it is basically an artificial trade barrier), percentages of industrial enzymes may be used to hit target numbers. Who really knows, that is just from little bits and pieces I’ve read about regarding a barely understood industry topic.