Kasu & Kasu Recipes
Should you frequent sake retailers with anything resembling a good selection of
sake, you will often, during the winter months, come across bags of sake kasu: beige chunks and chips of something resembling cheese or tofu. Sometimes, the unmistakable fragrance of sake wafts up from the
clear plastic bag as it sits on the counter.
What is sake kasu? In short, sake lees. After a tank of sake has run the course of its fermentation - anywhere from 18 to 32 days - what remains
is a white mixture of sake and the solids that did not or could not be fermented. This mixture, known as the moromi throughout its fermenting phase, must now be pressed to separate the almost-clear sake from the
There are several methods of pressing, but all accomplish the same thing: the sake is squeezed out, leaving a compressed form of the solids
, or lees, behind. This caked "stuff" is kasu. When sake is pressed by machine, the kasu comes out in nice, tightly pressed, square pancakes.
Usually this kasu is drier, having been manhandled by the high pressure of the pressing machine. Sake pressed in the older methods, using a big wooden box called a fune, in which the lid gets cranked down on
moromi in small canvas bags inside, will yield sake kasu that is more chunky, broken up, and formless. Also, some sake is pressed with more pressure applied to the moromi than other sake. Sometimes the
brewers want every last drop, at the expense of flavor, and other times sake is treated more gently, to maintain fine lines and subtle facets. The
difference is quite noticeable in the sake. It is also apparent in the firmness of the kasu.
Why is it so easy to find during the winter months? Because that is the
height of the brewing season. Since perhaps mid-December, most brewers have been pressing tanks of moromi on a regular basis, perhaps every other day (although larger kura press daily). Sake kasu has long
been used in Japanese cuisine, and imparts a unique flavor and touch. Below are a few tried and true examples of cooking with kasu.
Kasu Jiru (Kasu soup)
There are countless recipes and variations. Basically vegetables such
as carrots and daikon (radish) are boiled along with kasu broken into small pieces. Salmon is then added, with miso or salt added for flavoring
. Some recipes call for the reassuring addition of a dash of sake as well.
In his book An Insiders's Guide to Sake, Philip Harper presents a pork kasu jiru recipe from his wife Yasuko. Although salmon kasu jiru is
more common, I personally prefer this version, which is simple to make. That alone is reason enough to buy his book.
Break kasu up into small pieces and mix it with water to a pleasing consistency, similar to a soup. Heat it up and add sugar to taste, and a
dash of ginger. Warms you to the core in winter. There is another kind of amazake that uses over-the-counter koji and rice, creating a sweetish
beverage as the koji converts the rice to sugars. Note that neither type contains any alcohol.
(Kasu-marinated grilled fish)
Soak overnight a fillet of fish like salmon, or tai (sea bream ), in a thick porridge of kasu dissolved in water for ten days in an airtight container,
then grill and serve. Many kinds of fish can be grilled this way, provided you have the requisite patience. The sake pub Akaoni in Sangenjaya (03-3410-9918) serves several varieties of fish this way.
Grill or fry slices of kasu until soft. Dip in soy sauce or sugar. A particularly tasty variation (but a particular hassle to make) is to coat the
sides with miso and then fry. A delicious sake accompaniment (surprise, surprise). Naturally, flat, tightly-pressed chip-like kasu works better than chunky, moist kasu.
Sandwich a one to two centimeter layer of cream cheese with kasu, either in a casserole bowl or in cellophane wrap. Let it sit for 10 to 12
days, and enjoy on crackers with - get this - sake. I have just tried this one for the first time after being introduced to it at a sakagura; it's a bit hit-and-miss, but generally good, and never boring.
One I have never tried. Keep sake in cellophane wrap until it softens. Then mix it with sugar and form into manju balls, and grill over a gentle
flame. (You're on your own on this one.)
Not all sake kasu is used for cooking, however. Some is used as livestock feed (lucky pigs), and some is actually recycled and distilled to
make pure grain alcohol. Some of this even finds its way back into sake, when non-junmaishu sake is made. Sake kasu is relatively easy to find,
with even many department stores carrying it. It is relatively rich in protein, with 100 grams having as much protein as 70 grams of beef, as well as being full of vitamins B1, B2 and B6.
Not bad for the dregs of the sake brewing process.