First attempt: I must have done something wrong. A few reviewers mention putting in sugar at the beginning, but I just followed the directions that came with the starter. I did not use thickeners (I have pectin in the cupboard that I'll try next time), just Westsoy milk and a packet of the starter (three 8-oz. Ball jars was all I could fit in my rice cooker, which served as the incubator.) I cooked two for 7 hours and one for 8 hours. I did not monitor the temperature in the cooker. What I ended up with after storing overnight in the fridge was about what I started out with: soy milk. The 8-hour milk tasted slightly tangy, the other two not so much. I'm disappointed but will try again with Pomona pectin and maybe some sugar.

April 30: The second batch, with pectin, turned out thicker but tang-less. So for my third batch today, I'm trying no pectin and a warm water bath for eight hours in my turned-off rice cooker, assuming my problem is too high a temp.

Also, I discovered today that the fourth envelope of culture has a split on the bottom, and was spilling out, unbeknownst to me. But it doesn't matter, because if this third try doesn't produce the tang I like, that's it for me. I'll return to store bought. I don't have the patience for all this lab experimentation.

May 1st: After telling myself I'd try it one more time, I did more research on using a rice cooker. I combined a few how to's and ended up with thick, tangy yogurt. Finally! The secret is keeping the temp low enough. What I did was fill the rice cooker with water, put it on 'cook', and then warm up the soy milk on the stove. At 110 degrees, I stirred in half a pack of culture (for a pint of yogurt), poured it into two little Mason jars (I had shut off the rice cooker so the water would cool off a bit), and then set the jars floating in the bath (the water a comfortable warm bathing temp), closed the top, and forgot about it for eight hours, thinking cynically that the water would get too cold to create yogurt. But it didn't! I got thick, tangy yogurt. Success!

May 31st: After repeating the above method successfully, today (since I had run out of the powdered culture) I used a little over a teaspoon of leftover homemade yogurt as a culture in two cups of soy milk and did my usual rice cooker/warm water eight-hour soak. Somewhat to my surprise, it worked. I'm getting good at this!

I am using this product for quite some time and am happy with the quality of the product supplied to me.

I made every batch in an Instant Pot using various processes I found online. The one that worked best involved boiling the soy milk and letting it cool to around 110 degrees before mixing the culture into a small amount of the milk, then stirring that into the whole batch. After 14 hours, the yogurt is set and mild tasting but a little thicker in some places than others. The yogurt isn't thick enough to use as starter culture, so it's a little pricey. It's still less expensive than buying soy yogurt and I'm going to buy more, so it's pretty good but not perfect.

Here's mine. Its still being perfected. Feedback appreciated ----

I use an Instant Pot to make Vegan Yogurt, because once I press the Yogurt button and set the time, I don't have to do anything to it till its done. It can't scald because the temp never gets that high. The Instant Pot Yogurt button defaults to 8 hours, but I increase the time to around 12 hours for dairy yogurt, and 16 hours for vegan yogurt. You can always take it out early, or add time. But you don't want to run out of time and then have to heat it up again if you can avoid that. I hear slow cookers also work but have not tried it.

For vegan yogurts I use "enhanced" corn starch to thicken, and the right thickener is essential. I'm still experimenting, but my most recent attempt made a very thick vegan yogurt. Seach "clear gel powder corn starch" to find the "enhanced" version of corn starch on Amazon. It works best so far -- the only downside is that you need more heat to mix in the corn starch, so I heat my vegan milk to using the Saute option on the Instant Pot, and in this case you do have to watch the pot and change it over to the Yogurt setting before it scalds, but the thickener dissolves nicely. There are other types of thickeners that may work well too. I haven't tried Pectin yet.

The other essential seems to be to use the right non-dairy milk product, with a very high protein content. I have had the most success so far with Ripple brand, which is made with Pea Protein. There is a Silk brand product called "Silk Protein and Nut Milk" that is made with Almonds & Cashews & Pea Protein that also worked well for me. I can be hard to find but should get easier as pea protein products get more established in the market.

I also drain off the whey after it cools and before it goes in the fridge. (Save it for cooking soup or baking or pour it down the drain). It comes out fairly thick and thickens more in the fridge.

My evolving recipe so far is:
o 2 qts of high quality high protein non dairy milk.
o 3/8ths to 1/2 cup coconut sugar
o 2 tbsp of vanilla flavor, or 1/2 tbsp of vanilla paste (optional)
o 3/8ths cup of enhanced corn starch
o one packet of vegan yogurt starter
o 2 tbsp of Agar Agar powder (optional)

In an Instant Pot:
o heat 1/2 qt of the milk at the Saute setting for about 15 minutes, making sure it does not scald, then mix in the thickener.]
o add the rest of the milk
o mix in the remaining ingredients
o set the pot to the Yogurt setting, and increase the time to 16 hours.
o check to see how thick it is periodically after about 12 hours
o turn off the pot after you are happy with the thickness.
o after it cools for while, drain off the whey for 15 minutes using cheese cloth
o scoop out the yogurt, without stirring it, into the containers for the fridge

Yield for 2 qts of non-dairy milk after draining the whey is about 1.8 to 1.9 qts of yogurt.

I made soy yogurt with the product and it turned out great. But I will probably not buy again due to the expense.