ORIGINS: Soy milk, invented in China, was first mentioned in the first century AD. For a long time, it was only really enjoyed in China and didn’t gain much popularity even among other East Asian countries until the 1900’s. Now, it’s completely mainstream and remains one of the most popular non-dairy milks in the world, although it is slowly losing its edge to almond milk. But as someone who grew up on this drink, I still think it’s the best plant milk of all!
Homemade Soy Milk (Stovetop or Instant Pot)
- 1 cup dried soybeans 185 g
- 3 cups cold water 480 mL
- 8 cups water, divided into 6 + 2 1440 mL + 480 mL
- Soak the soybeans in 3 cups of cold water overnight (12–16 hours). If you plan to soak any longer please leave it in the fridge, or the beans will start to develop a sour smell.
- After soaking, pick out any debris (no need to de-hull them), rinse and drain.
- Add the clean, drained soybeans to a blender along with 6 cups of water. (See Notes if your blender is too small for this.)
- Blend on high speed for a minute or until very smooth. (If your blender has a smoothie mode, use that.)
- Strain the soybean mixture using a nut milk bag (see Recipe Notes if you don't have one of these) into a large cooking pot or Instant Pot. Rinse out the blender with 2 more cups of water and pour that through the strainer.
- Save the okara for some other use, then cook the soy milk using one of the two options below.
- Set the pot containing soy milk on medium heat. Stir frequently and keep a careful watch over the pot because soy milk foams over very quickly when heated, just like real milk! Be ready to take it off the heat at any moment.
- The milk foam will gradually increase while cooking, but just keep stirring to keep it down. At some point, the foam will keep rising and rising despite continuous stirring. This is when you should quickly take it off the heat. The foam will slowly subside… and once it's cool enough to touch you can enjoy it right away or pour it into containers for storage (it will keep up to five days, refrigerated).
Instant Pot Option
- Set the Instant Pot on PRESSURE COOK mode ("MANUAL" on older models) on high for 10 minutes. Allow pressure to naturally release before opening. You can drink it right away (after cooling it down, ofc) or store for up to five days in the fridge.
If your blender is too small to hold the soybeans along with 6 cups of water, you can reduce the water amount until it’s at a safe level for the blender. Just add the remaining water during step 5 when you’re rinsing out the blender. The important thing to remember is that you are adding 8 cups total to your drained soybeans; how much you add in step 4 vs step 5 doesn’t really matter as much, although more water in step 4 makes it easier for the blender to blend the soy milk smoothly.
Don’t have a nut milk bag? You can also use a piece of cheesecloth, folded two or three times, or a muslin sheet. However, a nut milk bag is a great investment if you plan on making your own plant milks a lot; it works for any kind of milk (soy, almond, cashew, sunflower seed…) and the bag shape really makes straining easier. I’ve also used this Asian soup bag that my mom bought from who knows where. Basically, you need the holes in the cloth to be this size or smaller.
Also note, because this is all natural soy milk, it will tend to separate a bit on the fourth or fifth day with a thicker liquid settling on the bottom. This is fine, just shake before drinking.
Soybean–Soy Milk Conversions
This is where it gets kinda geeky. Here is the basic soybean–soy milk conversion:
1 cup dried soybeans (185 g) = 2 3⁄4 cup soaked soybeans (440 g) + 8 cups water (1920 g) = 8 cups cooked soy milk (1920 g) + 1 3⁄4 cup okara (370 g)
So for example, if you want to make only a quart (4 cups) of soy milk, you’ll want to start with 1/2 cup (around 90 g) of dried beans, which would produce 4 cups cooked soy milk (960 g) and 185 g of okara.
Note, it looks like there is some discrepancy between the soaked soybean and soy milk numbers (440 + 1920 ≠ 1920 + 370). This is due to evaporation, leaving soy milk or okara behind in the cooking pot or straining bag, etc.
Also, each of these numbers is an average calculated from data I collected all the previous times I’ve made soy milk. I mostly rely on weight measurements now instead of dealing with measuring cups. I would say they’re pretty accurate based on my experience!
If you’re interested in this kind of volume-to-weight ratio stuff, I recommend checking out the beans conversion calculator for soybeans and other types of beans as well as King Arthur Flours ingredient weight chart for bakers.
Where to Buy Dried Soybeans
I got my soybeans from Nuts.com, which has free shipping options to the US and Canada. They are a little more expensive than storebought beans, but I’ve been really impressed by the quality. Since I am a huge soy fan, and dry soybeans last forever, I bought the 25lb bag for $57. It’s been three years and they’re still going strong.
You can buy smaller quantities of soybeans at many bulk food stores. I’ve also bought 1lb bags of dried soybeans from T&T.
Also, apparently canned soybeans are a thing, though I’ve never seen them in stores here. Yes, you can use canned soybeans for this recipe. Reduce the total water volume from 10 cups to 8 cups, and use the beans conversion calculator to figure out how much cooked soybeans to use in place of dried ones.
Don’t Throw Out the Soy Pulp!
The pulp you’re left with after straining homemade soy milk is still full of protein and other nutrients. It’s also known as okara or 渣豆腐 (tofu dregs). It makes the soy milk gritty, which is why we strain it out, but it still has nutritional value. And in the spirit of reducing waste in the kitchen, I always try to use it up instead of throwing it out.
For each batch of this recipe, you’ll end up with about 1 3⁄4 cups (370 g) of okara, though this will depend a bit on how much you squeeze. (Since I’ll be using the okara anyway, I don’t really spend too much time on trying to squeeze out every drop. It takes me just 2–3 minutes to do the straining.)
You can do a lot of different things with soy pulp. I am working on putting together a Okara Series to share some of my favourite recipes, but for now here’s some recipes from other sites that I’ve made and enjoyed:
Soy Milk Uses
Well guys do I really have to say it… use it anywhere you might use regular milk. Cereal, protein shakes, baking cakes and breads, alfredo sauce… but I usually end up drinking most of it straight! It’s great unflavoured or you can also stir in a few drops of vanilla extract and a couple spoonfuls of syrup. Along with some okara recipes, I’ll be working on putting out a couple of soy milk recipes for you all!
Nutrition, Cost, and Emissions Information
One cup of homemade soy milk is 103 cal (note this is slightly overstated because it includes the okara), costs less than $0.12, and releases 46 gCO2e of carbon emissions into the atmosphere.
Calculation for full recipe as written (8 servings):
Feel free to contact me for sources on the nutritional and carbon emissions information presented here. Note that I am not a nutritionist and guidelines on this page are provided for informational purposes only.