Homemade Shio-Koji (Salted Rice Malt) and Salt Pork
Just combine koji with salt and water, and leave it to mature and ferment at room temperature to create shio-koji, a multi-purpose flavoring ingredient. It keeps for a year. Just put this on meat to cure it easily.
Koji (freeze dried: available in Japanese supermarkets, or fresh koji)
Salt (30% of the weight of the koji)
400 ml + up to 200 ml (later on)
For the salt pork:
Pork belly (or pork shoulder or filet), block
as much as you like
Shio-koji (about 10% of the weight of the meat)
Example: For 400 g of pork use 2 to 3 tablespoons of shio-koji
Make the shio-koji: Put the shio-koji ingredients in a storage container and leave at room temperature. Mix it up once a day. In 7 to 10 days, when it becomes thick and porridge-like and the rice grains start falling apart, it's done. Store in the refrigerator.
The innoculated rice grains (the koji) will absorb water as it matures, so keep adding more water every 2 to 3 days so that the grains are always covered. Add up to 1.5 times the amount of rice in water.
Make the salt pork: Spread the shio-koji evenly over the surface of the pork. Wrap in paper towels, then wrap again in plastic wrap. Put the wrapped meat in a plastic bag and refrigerate.
After 2 to 3 days the meat will be cured and become a pretty pink color. Moisture will come out of the meat too, so change the paper towels. The meat is ready to eat in 3 days, up to 10 days.
This pork has been cured for 10 days and cut into 1 cm thick slices. Just pan fry in a frying pan without any added oil over medium-low heat. Don't wipe the shio-koji off; it burns easily though so pay attention!
This is sliced pork roast that's been marinated in shio-koji for 3 hours. I served it with user Orangeday's "Avocado + Sake Lee Dip" (Recipe ID: 1644716) for a double punch of koji.
This is Whole Tomatoes Marinated in Shio-Koji (Recipe ID: 1534473).
Here are three more shio-koji recipes. Microwave-steamed Chicken Tenders (Recipe ID: 1594323); Sautéed Chicken (Recipe ID: 1534204); Bettara Daikon Radish (Recipe ID: 1640147).
With shio koji soboro: Yum Woon Sen with shio-koji soboro (Recipe ID: 1557977); Rice with shio-koji (Recipe ID: 1613801).
Here are more shio-koji recipes. Nagaimo marinated in wasabi and shio-koji (Recipe ID: 1703667); Avocado marinated in shio-koji (Recipe ID: 1680387).
Shio koji in hot pots: Try a spicy hot tofu hot pot (Recipe ID: 1607100) or a koji and sake lees hot pot (Recipe ID: 1670779).
Using shio-kojji and amazake homemade seasoning mixture. Sweet and savory shio-koji, (Recipe ID: 1684858).
A lot of dried koji comes in 200 g packs, so you can just halve the water and salt if you are using one of those. However, dried koji absorbs a lot of water, so please keep adding more water when needed.
Story Behind this Recipe
Koji or rice malt is indispensable for making miso or amazake. The custom of making shio-koji or salt fermented rice malt has been around since olden times in the Tohoku region apparently. When the malt is fermented with salt, the edge is taken off the salt and it becomes sweet and well rounded - a magical salty flavoring ingredient. It's a multi-purpose ingredient. Use it instead of salt. The amino acids in the shio-koji help to tenderize meat and make it delicious.
As long as you have shio-koji, you just need to spread it on the meat. For thinly cut meat for yakiniku or chicken, you just need to let it marinate for 1 hour, up to half a day. The results are mildly salty and delicious! There are two types of "koji": one grows on soy beans, and the other on rice grains. Here we use the "koji" that is grown on steamed rice and then freeze-dried. You can buy this in bags at a Japanese supermarket.