Kasuzuke is a type of Japanese pickle or tsukemono made with sake lees, the by-product from the refining process of sake production. With a deep aroma and slightly alcoholic flavor, Kasuzuke is perfect for marinating fish, meat, and vegetables.
Gather all the ingredients for the Kasudoko. Put 1 lb sake lees (sake kasu) in a medium bowl and bring it to room temperature on the counter so it becomes much more pliable.
Check the texture of the sake lees with your fingers. If they feel solid and firm, add the sake first and microwave for a few seconds until it becomes pliable. Otherwise, combine the sake lees with 2 Tbsp miso, 4 Tbsp sugar and 1 Tbsp Diamond Crystal kosher salt first.
Using your hand, mix the ingredients and knead well until thoroughly combined.
Add 3 Tbsp sake, a little bit at a time, and knead to combine each addition into the sake lees mixture. Check the consistency to see if you need to add more sake. The consistency you’re looking for is similar to miso—not too loose and not too hard. Each sake lees brand has a different consistency and you may not need all of the sake (or you may need more).
Knead until the kasudoko becomes a paste form and then transfer it to a glass container in which you will pickle your ingredients.
To Make the Cucumber Kasuzuke
Gather all the ingredients for the cucumber kasuzuke.
Sprinkle 1 Tbsp Diamond Crystal kosher salt over 5 Japanese cucumbers. The amount of salt used is 2% of the weight of the cucumbers. Here, I use 500 grams of cucumbers; therefore, I’ll need 10 grams of salt. Using your hands, rub the salt into the cucumbers.
Set aside for 1 hour. The salt will draw moisture from the cucumbers.
After 1 hour, dry the moisture on the cucumbers with a paper towel. Then, transfer the cucumbers into the Homemade Kasudoko.
Completely cover the cucumbers with the kasudoko.
Once the cucumbers are embedded, cover the container with the lid. Store in the refrigerator for a half day (maximum 24 hours).
With clean hands, take out the cucumbers from the kasudoko, leaving the sake lees in the container. Wipe off the kasudoko from the cucumbers with your fingers. It‘s normal to leave some kasudoko residue. You do not need to wash the cucumbers.
Slice the cucumbers and serve in a dish. Tsukemono is always served along with steamed rice and miso soup. Enjoy the cucumber kasuzuke within 3 days.
To Store the Kasudoko
You can keep the kasudoko in the refrigerator or freezer and re-use it for up to 6 months (depending on how often you use it, though). If you use kasudoko for seafood or meat, NEVER use it for ingredients that you will serve raw, such as vegetables. You will need to make a separate batch just for meat or fish. If your kasudoko smells sour or becomes watery, discard it.