I had been worried about yogurt for a while… I know, it sounds absurd, there are so many bigger things to be worried about, but yogurt even made it to several blog posts: The decision fatigue of sustainable living and were on my mind when drafting My sustainability fails and A week of waste, an assessment. Here, my problematic friend:
It’s marvelous but so wasteful…
So finally my judgemental side won, I did a basic google search, and found out that my intuition was correct: in theory could make my own soy yogurt with the utensils I already have and by buying only one more yogurt to serve as a starter. These have been my base recipes: Homemade Soy Yogurt and Soy Yogurt.
By now I have done that enough times to give my own advice with some confidence, and hence tell you that all you need is an oven, a kitchen thermometer (do not skip this, it will end up in runny yogurt and burnt knuckles), glass jars, a no-additive soy milk and a no-additive soy yogurt. That is all, no yogurt machines and no thickeners. The most important part – as wit hall fermented adventures – is to understand which aspects are flexible and which ones are not. Let me tell you!
Step 1: Gather your people.
Your milk and your yogurt. I already said, thickeners are optional. I have decided to leave them behind, but you can experiment with agar agar and let me know.
A key thing that will make or break your yogurt: the starter yogurt has to be active which means room temperature. I recommend weighing in your 150-200g of starter yogurt and leave it on the counter overnight. You want your little culture friends to be active and ready to reproduce, not cold and sleepy! The initial temperature of the milk is not important, as you will warm it. As for the choice of milk, so far all basic natural soy milks I have tried have worked. To keep it simple I just use a whole 1l carton. In my dreams I do this with DIY soy milk, but the reality hasn’t caught up to that just yet.
Step 2: Warming the milk.
This is where you have to be vigilant and warm it as hot as possible without boiling. 90-95ºC will do the trick!
Step 3: Waiting for the milk to cool down.
This is very important! Once your milk is hot, you turn it off and wait for it to cool down to around 45ºC. It takes quite a while, btw… just enough for you to forget it and not enough to do something else and then come back to it, so pay attention.
This is why you need that kitchen thermometer. In the previous step you would be able to see the milk almost boiling and react accordingly but this is trickier. Although sources I found said you could do it just with your fingers, I burnt my fingers repeatedly in my fear to miss that perfect temperature. Also, this implies keeping your fingers very clean. Just get a thermometer, they are useful in kitchen.
This is also the time to start preheating your oven to 100-120ºC. You know your oven best to time it as to produce the least idle oven time, just keep in mind that you will want it that warm some 5 minutes after this milk has cooled enough.
And you can prepare the jars. I find it the most convenient to have them directly on the oven tray.
Step 4: Mixing and pouring.
Once the milk is at those magical 45ºC, mix it well with your room temperature yogurt (and any thickener if you are using that). You can also do this in the same pot you boiled and then cooled the milk.
Then fill those jars with your future yogurt. Clean up any drips from the oven tray, as you don’t want it to clean it off burnt afterwards.
Step 5: Oven.
Put your tray in and *switch the oven off*. Nope, you are not baking these people, you are just ensuring that they are nice and cozy to make delicious bacteria babies. So you do not open the oven for at least 8h, better make it 12h. Overnight is good. I suggest to put a piece of tape to remind you to not to open it and to get it out afterwards.
Step 6: Munch!
After those oven hours you will have yogurt. For the the best results I recommend to transfer your jars to the fridge, it helps if your batch has come out a bit runny. You also want to keep it there to slow down further fermentation. And most of us enjoy yogurt cold anyway.
But it doesn’t have to be runny. My first batch stood vertical, and I was very proud:
Season is very important. As with kombucha or any other fermentation, temperature matters. So be prepared that your summer yogurt will be thicker than winter yogurt. As I use mine mostly for sauces (instead of mayo for all the potato salads!), thickness is not the most important aspect for me. Trial and error will show you what will cover your yogurt needs.
If you fuck up completely – I once distractedly poured the yogurt into the hot milk instead of waiting for it to cool down, and it came out just a teensy bit thicker than it went in the oven – you can still use the result in porridge or smoothies.
And, yes, of course, keep your last 150-200g of your yogurt to make the next batch.
That’s about it… See, you don’t need a yogurt machine the same way as the people who (surely accidentally) invented yogurt didn’t have one. Will you try it? Please let me know if you do… ♥