The questions were:
a) can you make soy yogurt at home from soy milk?
b) can you strain any resulting yogurt to get a thicker result?
c) will it then freeze?
d) can you cook with it - does it split?
The reason was because a very good friend can't have much dairy now and, due to various intolerances and downright allergies, her diet is pretty restricted anyway. I'm experimenting before she comes to stay! She's not really a cook and she's certainly not a food experimenter so I'm doing it for her.
a) Because she can still take a little dairy, I mixed nearly a litre of unsweetened soy milk (from Aldi) with a couple of spoons of natural yogurt and used my Instant Pot on the yogurt setting. If I didn't have that, I'd have used my little electric yogurt maker from Lakeland.
I don't make my yogurt any other way!
The simple answer is yes, you can. Seven hours later it was beautifully set. A pretty plain taste, pleasantly neutral and it will be easy to flavour.
From the wonderful Lakeland, you can buy non dairy soy yogurt starter so, in the interests of culinary progress, I have invested in a packet and will report back when I have used it - which won't be for a few weeks. There's also the option of using some from the last batch which is feasible if you only use soy yogurt and make batch after batch.
b) Yes, it strains really well to get a thicker product more like Greek yogurt. I have a yogurt strainer but you can easily use a metal sieve with a piece of muslin, cheesecloth or a very clean tea towel to get the same effect. It doesn't look creamy but the texture is nice and smooth - it's not 'grainy'.
I'm looking forward to using it.
c) and d) I haven't tried these yet. I'll pop some of what I have made into the freezer today and we will see. As far as cooking/splitting is concerned, I suspect that it will but Google has let me down on this one so far. All the recipes I have looked up use the yogurt at the end as a dip or a cooling sauce so I need to keep looking.
I can definitely use the unstrained version in soda bread instead of buttermilk or in scones, not that I make scones right now, but you can.
So far, so good!