It’s recommended to soak dried shiitake mushrooms in water to soften them before use. Shiitake mushrooms contain guanylate, a substance not found in other ingredients. This substance enriches and enhances the flavor of food, making it a common practice to save the soaking water for later use in cooking. But can I eat the soaking water from dried shiitake mushrooms? Is it safe? Is it really suitable for cooking?

Many recipes recommend saving the soaking water from dried shiitake mushrooms to add a rich aroma to soups, stir-fries, and rice dishes. But is this soaking water really safe? If it’s contaminated during cultivation or transportation and contains harmful substances, using it in cooking can pose a food safety risk.

Characteristics of high-quality shiitake mushrooms:

Rich aroma
Light yellow gills
Trimmed stems
Brown, shrunken surface

Characteristics of low-quality shiitake mushrooms

(commonly seen in compressed flat shiitake and shredded shiitake mushrooms):

Short stems
Dark gills
No aroma
We recommend avoiding dried shiitake mushrooms that appear limp.

Can shiitake mushroom water be eaten?

Even if dried shiitake mushrooms are free of heavy metals and pesticide residues, there is still a risk of contamination from dust and indirect residue from splashing. Although shiitake mushroom water contains some dissolved flavor compounds that can enrich the flavor of dishes, it is still recommended not to use it for food safety reasons.

When soaking dried shiitake mushrooms, gently stir them occasionally to ensure that both sides of the cap are in contact with water. For best results, change the water several times after soaking and turning. Kelp, bonito flakes, or dried fish can be used in cooking to replace shiitake mushroom water for added flavor.