I was elated that a new local Chinese restaurant had freshly made Chinese crullers – “fried devils” (You Zha Gui or You Tiao) and salty soy milk soup (Xian Dou Jiang). The You Tiao were wonderful, but the Xian Dou Jiang was curdled; it tasted fine, but I like it in a creamy/custardy style. I looked up recipes for Xian Dou Jiang online and tried making it with supermarket plain soy milk, but was dismayed with the flavor. The recipes warned of the need to use unflavored soy milk, but even the boxed soy milks I tried labeled “plain” has been sweetened, completely ruining the taste of the Dou Jiang.
So I looked up how to make soy milk. I found various recipes (for example, the one from Chowhound) and many recommendations for a $100 machine to make it. Not wanting to wait or spend the money until I could find if I could make Dou Jiang as I remembered it, I experimented with a few of the recipes and have come down to this one that works for me.
First the soybeans. I went to my local Asian supermarkets and looked for dried soybeans in the dried beans section. No luck. I found they’re so popular that they’re kept with the fresh produce. A manageable sized bag of about 3 pounds of beans sold for under $3. Note that dried soybeans are round; they don’t look like edamame.
I also needed a way to squeeze the milk from the blended soybeans. I didn’t think that regular cheesecloth would be fine or strong enough to stand up to the pressure of being squeezed hard, so I tried “Ultra Fine Cheesecloth” that I found at Sur La Table.
Here’s the recipe I ended up with. It produces about 10 cups (1/2 gallon and 1 pint) of soy milk, which works out to about 80₵ per half gallon.
2 c dried soybeans (about 13 oz)
1 slice ginger
Soak 2 cups dried soybeans overnight – at least 12 hours. Drain, rinse, and pick over the beans to remove any pebbles or other debris (I’ve never found any, but you wouldn’t want to put rocks into your blender!) The beans will have swelled to about 5 cups and regained their bean shape.
Blend the beans in batches: 1 cup of beans with 2 cups of fresh cold water. I run my blender on Chop for 30 seconds and then Puree for about 1 minute, to make a smooth paste. It comes out with a layer of foam.
Take up the corners of the cheesecloth and twist, squeezing out at much of the remaining milk from the beans as you can. Dump the dregs into a bowl; reserve for use in other cooking (it’s a good protein source – I stir fry mine with leftover rice and vegetables to make fried rice). Repeat with the remaining beans, producing about 10 cups of raw soy milk.
Put the soy milk and ginger slice into a large pot and bring it to a boil over high heat, stirring periodically, scraping the bottom of the pot with a flat nylon turner and watching it to ensure it doesn’t boil over. As it starts to steam, watch very closely since it will quickly foam up and boil over! As the foam rises, quickly remove the pot from the hot burner and stir, letting the soy milk cool in the pot. Strain the milk to remove the ginger and store in containers.
Refrigerate and use as soy milk, for Dou Jiang or Dou Fu Fa. It should keep for about 3 days. Freeze the soy dregs in a freezer bag for later use.
There will be a skin stuck firmly on the bottom and sides of the pot – scrape off as much as you can with a nylon turner. Soak and wash the pot with a nylon scrub pad to remove the remaining soy coating.