Step 1

Before you begin making the soy yogurt, sterilize everything you'll use, as you don’t want the yogurt cultures competing with any bacteria on/in the tools. This includes the pot and bowl for the milk, the glass jar (or small jars) to store the yogurt, and the spatula and/or spoon (wooden or silicone) you will be using.To sterilize the tools, wash them with hot soapy water and then dry them in the oven (no plastic parts) for 10 minutes at 160ºC.

Step 2

If you're using homemade soy milk, then you can follow the method outlined here.First, mix the agar-agar and cornstarch with a little milk and whisk until it's a smooth slurry.

Step 3

Then add the soy milk and slurry into a large pan and heat over low-medium heat* until it reaches 85ºC/185ºF**. Stir occasionally, so the milk doesn’t stick to the pot's bottom. Don't rush this step - it could take 30-40 minutes to warm it up enough.

Step 4

Once the temperature is reached, remove it from the stovetop and allow it to cool down to 45ºC/113ºF. It's essential to wait until the temperature drops before continuing with the next step (or else you may kill the yogurt starter immediately). This can take a further 30-40 minutes.

Step 5

Once the milk has cooled, add your yogurt starter, and stir gently until completely mixed in.If using a powder starter, dissolve it with a bit of milk to create a ‘slurry,’ then pour in the pot.

Step 6

Pour the soy milk yogurt mixture into your containers of choice. I use individual serving small glass yogurt jars.

Step 7

Place the glass jar/s in a warm environment to “incubate” overnight. I wrapped mine in a warm blanket and left to intubate for 12 hours in the oven (while it's switched off). The longer it ferments, the tangier the yogurt will taste.Chef's note - I'll often make this yogurt in the evening after my dinner, so the oven is often ever so slightly warm still. If you haven't used the oven for a while, you can pre-heat it at 400F/205C for just 2-3 minutes, then switch it off before placing the jars in to incubate.If you want the yogurt very thick and sour, you can incubate it for up to 24 hours. Then move it to the refrigerator.

Step 8

After the incubation period, I like to refrigerate it for another 6 hours before eating any as it further thickens. Then, flavor or sweeten if preferred and dig in!

Step 9

Store the soy yogurt in the fridge in airtight containers for between 4-5 days.I wouldn’t recommend freezing the yogurt as the cornstarch doesn’t remain thick when frozen and thawed.It is possible to sous vide can these for longer-term storage (4-6 weeks), though it isn't something I've tried.