Koji's influence on Japanese cooking cannot be emphasized enough. As grains or soybeans fiddled with Koji mold, they have crafted Japan's cherished fermented foods such as authentic soy sauce (shoyu), sake, and miso. Not only has Japan celebrated Koji, but also renowned chefs like Noma's René Redzepi and Larder's Jeremy Umansky, largely due to its combination of sweetness, floral essence, funkiness, and profound savory taste. Koji, indeed, holds an esteemed place in the world of chefs.

Koji is crafted from grains like rice and barley or soybeans altered with Aspergillus Oryzae mold. Amazingly, 'Koji' can also refer to the mold itself, christened 'koji-kin' in Japan. Koji's function varies extensively from numerous yeasts and fungi used in fermentation procedures. Unlike Baker's yeast, which is a simple single-cell organism converting sugar into ethanol and carbon dioxide, Koji has a more intricate process. It develops a network of strands or mycelia while generating enzymes, prominently amylase, which converts starches into sugars. This astonishing transformation is what blesses sake and miso with their sweet and delightful fragrance. Koji's other enzymes disintegrate proteins into amino acids, making it an excellent meat tenderizer.

An array of dry and liquid Koji-based products, easily available online or at any Asian market, are used widely by Japanese home cooks. The most basic form, Koji-inoculated rice, can be paired with rice or grains to whip up amazake, a sweet fermented beverage traditionally served hot during New Year's celebrations. Combined with salt and water, dried Koji rice becomes an ideal medium for fermenting quick pickles and preparing traditional Japanese condiments like shoyu koji and shio koji.

Once this Koji rice is crumbled, mixed with soy sauce, and allowed to ferment, it's transformed into shoyu koji, a condiment boasting of umami goodness. Though the meticulous preparation calls for daily attention for about a month, readymade jarred versions are available. As a substitute for soy sauce or a marinade for seafood and meat, shoyu koji does wonders.

Liquid shio koji holds more versatility than its dry counterpart. This all-natural bottled condiment made from inoculated rice, water, and salt works beautifully as a marinade, tenderizing meat and enhancing the browning process during cooking. Adding a dash of it can result in the perfect flavor balance for soups and stews while deepening their flavors. It’s also a delightful addition to cooked vegetables and soup noodles.

It's essential to note that not all liquid shio koji is the same, and some varieties bear quite an intense flavor. For beginners on their Koji journey, the readily available Hanamaruki brand is a good start due to its limpid texture and resemblance to the color of green tea. Once you've hopped on to the Koji bandwagon, you'll be pleasantly surprised by the numerous culinary avenues it can lead you.