Duyu — Korean Soy Milk and How It Differs From the Western Version

Duyu (두유) is the Korean word for soy milk — du (두 = soy/bean) + yu (유 = milk/oil). The term covers both homemade soy milk (made by soaking, cooking, and blending whole soybeans) and commercial varieties, but these are very different products.

Homemade vs Commercial Korean Duyu

Homemade Korean duyu (for kongguksu broth or fresh drinking): Made from soaked, cooked, blended whole soybeans. No additives. Not sweetened. Not shelf-stable. The flavor is prominently soybean — nutty, slightly sweet from the beans themselves, with a slight grassy note from the skin. The protein content is high (8-10g per 240ml) because the entire soybean is used. This is the broth for kongguksu (cold soy noodles) and the fresh variety sold at traditional Korean markets.

Commercial Korean duyu: The most recognized brand is Beondegi and, more broadly, the Sahmyook brand's sweetened versions. Commercial duyu in Korea is typically lightly sweetened (3-5g sugar per serving), heat-treated for shelf stability, and has a cleaner, milder flavor than homemade. Available in small aluminum-foil cartons at every Korean convenience store.

Western commercial soy milk: Typically made from soybean extract (not whole beans), often significantly sweetened, with vanilla flavoring added. Designed to replace dairy milk in coffee and cereal — a different product goal than Korean duyu.

How to Make Duyu at Home

This is the same process as making kongguksu broth:

1. Soak 200g dried soybeans in cold water 8-12 hours
2. Drain. Boil with fresh water for 15-20 minutes until completely soft
3. Drain (save or discard cooking water)
4. Blend with 1 liter cold water until completely smooth
5. Strain through fine cloth, pressing firmly
6. The strained liquid is fresh duyu

Season very lightly with salt (1/4 tsp). Serve cold. No added sugar for the traditional version.

Shelf life: 2-3 days refrigerated. The fresh product continues to develop flavor as it sits.

Cultural Position

In Korea, duyu occupies a different cultural position than in the West. It is not primarily a dairy substitute — soy milk in Korean food culture predates dairy milk by many centuries. It is an independent beverage category rooted in soybean cuisine rather than an alternative to another category.

Korean health food culture around soy products (dubu/tofu, duyu/soy milk, doenjang, cheonggukjang) treats soybeans as a primary protein source in their own right, with duyu being the most easily consumed form of whole-soybean nutrition.

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Duyu demonstrates how the same basic ingredient (soybeans + water) creates different cultural and culinary objects depending on context. The Western soy milk industry reimagined soy as a dairy substitute; Korean duyu remains primarily a soybean product valued for what it is — the direct liquid expression of the bean.