Sake kasu, also known as sake lees, is a byproduct of the sake (Japanese rice wine) production process. It is a thick, paste-like substance left behind after pressing the liquid from the fermented rice mixture used to make sake. Sake kasu has been utilized in various culinary and skincare applications due to its unique flavor profile and potential health and beauty benefits.
Here are some key aspects of sake kasu:

1. Formation:

Sake kasu is formed during the fermentation process of sake production. Sake is made from rice, water, yeast, and koji mold. After fermentation, the mixture is pressed to extract the liquid sake, leaving behind the solids, which include the sake kasu.

2. Composition:

Sake kasu contains residual rice solids, yeast, proteins, and other components from the fermentation process. Its composition can vary based on the specific sake production methods.

3. Health Benefits:

While not extensively studied, some believe that sake kasu may contain beneficial compounds, including enzymes and probiotics, due to its fermentation process. However, more research is needed to confirm specific health benefits.

4. Skincare:

Sake kasu is also utilized in skincare. It is believed to have moisturizing and exfoliating properties. Some skincare products, such as soaps, creams, and masks, may include sake kasu for its potential benefits.

5. Traditional Practices:

In Japan, sake kasu has a long history of traditional use. It has been valued not only for its culinary applications but also for its potential role in promoting overall well-being.

6. Sustainability:

The use of sake kasu in various applications contributes to sustainability by utilizing a byproduct that might otherwise go to waste.