For thousands of years, the Japanese have used koji, a kind of rice mold, to make everything from sake to soy sauce. More recently, Japanese chefs discovered that when you mix koji with salt and allow it to ferment — thus making shio koji — you wind up with this super-powerful condiment that’s capable of tenderizing meat and adding a boost of umami to a wide range of dishes. At this workshop at Preserved (5032 Telegraph Ave., Oakland), you can learn how to use the ingredient that some forward-thinking chefs have touted as “the new MSG” in your own home cooking. Umami Mart co-owners Yoko Kumano and Kayoko Akabori — Oakland’s resident authorities on all things Japanese — will be your instructors. Tickets are available via Eventbrite.com.