Everything You Need to Know About Sake Lees
Sake Kasu, or Sake Lees, is the biproduct of sake production consisting of yeast, mashed rice, sugar, and enzymes. Its high concentration of nutrients and its tangy, sweet, floral, and umami flavor make it the perfect ingredient for pickling, marinating, or as an additive to soups, broths, and beverages.
In Western culture, the zero waste and sustainability mindsets have only recently emerged in the mainstream. In non-western cultures, however, these concepts have existed for ages. In Japan for instance the “nothing goes to waste” mentality is a fundamental belief with deep cultural roots. This defining principal has led Japanese cooks to discover nutrient rich and flavorful treasures in what would otherwise be considered trash. One of these diamonds in the rough is Sake Kasu.
Here is a video with Michael Vera from West Coast Koji that shows how he pickled daikon radish using sake lees from his latest batch of sake.
What Is Sake Kasu?
The sake-making process begins by combining steamed rice with a fungus called koji which releases enzymes that convert the rice’s starch into sugar. Once the sugar releases, producers add yeast which converts the sugar into alcohol. Finally, producers press the fermented rice mash, separating the liquid sake from the solid remnants – the lees.[2]
Flavor and Nutrition
The combination of yeast and enzymes contribute a powerful umami flavor to sake lees. However, because of the fermentation process, kasu also possesses the same sweet, tangy, funky, floral nodes as sake itself.[3]
Sake kasu’s texture can vary depending on how it is packaged. Some varieties come in sheets which provide a firm texture while others come much more loose and crumbly.[5]
Besides possessing a rich, complex flavor profile, sake lees contains incredible nutrients. One study conducted in Japan found that sake kasu contains significant levels of vitamins B6 and B3 and can help improve skin quality. [6]
Another study published in the Journal of Nutritional Science and Vitaminology revealed that sake lees contains high levels of protein, suggesting that “sake lees powder can be assessed as a favorable candidate for not only protein-rich but also hypolipidemic provisions.” [1]
Common Uses for Sake Lees
Sake Lees is most commonly used as a pickling agent.[5] Chefs burry vegetables like carrots, daikons, and cucumbers in kasu, then refrigerate the vegetables for hours, days, weeks, or even months. The enzymes and yeast in the kasu work to break down the vegetables while effusing them with active ingredients and imbues them with a sweet, tangy, slightly fermented flavor much like kimchi. After the process is finished, the vegetables are wiped clean and ready to enjoy on their own or as a garnish.
Another common use for kasu is as a marinade for fish or meat. Similar to the pickling process, the meat is buried in kasu – often mixed with ingredients like miso, sugar, and salt — and refrigerated for several hours. [2]
Home cooks in Japan use kasu for all kinds of dishes – from bread to icecream, even cheesecake! One popular dish in Japan involves rolling sake saku out until it’s flat, then toasting it over a grill until it becomes firm and crispy like a cracker. [2]
One final recipe is a beverage called amazake. Amazake is a sweet, warm, winter beverage comparable to champurrado or horchata. While this beverage is often called “sweet sake,” it can be served in a non-alcoholic form to be enjoyed by the whole family. [3]
As chefs embrace sustainable practices, hey find inspiration in other cultures. As they discover better ways to produce and prepare food, they often discover unique, flavorful, and nutritious gems like sake lees in the process.
References
[1] N. Tsutsui, Y. Yamamoto and K. Iwami, “Protein-Nutritive Assessment of Sake Lees Obtained by Brewing from Liquified Rice,” Journal of Nutritional Science and Vitaminology, vol. 44, no. 1, pp. 177-186, 1998.
[2] E. Liu, “Sake Kasu: Flower of the Garbage,” Edible Boston, 2018. [Online]. Available: https://www.edibleboston.com/blog/2018/6/11/sake-kasu-flower-of-the-garbage. [Accessed 2020].
[3] M. Sula, “Secret Ingredients: Sake Lees,” Chicago Reader, 3 December 2012. [Online]. Available: https://www.chicagoreader.com/Bleader/archives/2012/12/03/secret-ingredient-sake-lees. [Accessed April 2020].
[4] M. Itoh, “With Sake Rice, Nothing Goes to Waste,” Japan Times, 11 January 2011. [Online]. Available: https://www.japantimes.co.jp/life/2011/01/28/food/with-sake-rice-nothing-goes-to-waste/#.XqdJ5ChKjDe. [Accessed April 2020].
[5] “Sake Kasu,” [Online]. Available: https://www.uwajimaya.com/uwajipedia/detail/sake-kasu.
[6] M.-U. Hiroko, S. Masahikio, Y. Shoichiro, M. Minoru and M. Kazuhisa, “Amazake Made from Sake Cake an Rice Koji Suppresses Sebum Content in Different Hamster Sebacytes and Improves Skin Properties in Humans,” Biscience, Biotechnology, and Biochemistry, pp. 1-7, 2020.
