How to Make Yogurt

I used to think that making yogurt was difficult. You need a machine and a special yogurt starter and have to plan it out, and ugh, too much time and effort. Easier to just buy it, right?

But I was bothered by the number of plastic containers Zach and I were going through. Back in 2011, we were probably eating one or two 750 g yogurt tubs a week, and that added up to a lot of plastic over a year.

Zach started making yogurt for us, using techniques he had learned from the Weston A. Price Foundation, which focuses on a traditional diet that includes fermented foods, and Sandor Katz, aka the fermentation guru.

After a while, I took over making the yogurt and streamlined Zach’s technique even further to make it as simple and derp-proof as possible. Check it out!

Whole Milk (at least 3% milk fat)
Plain Yogurt (with live cultures)

Medium Pot
Measuring Cup
Big Bowl with Heavy Bottom
Wooden Spoon
1 Litre Glass Jar with Lid
Towels and Belt / Tie


  1. Clip your thermometer onto your pot so that it’s about 1” from the bottom. Pour in 1 litre of milk.
  2. Put the pot on the stove and turn the heat to low, or 2 or 3 out of 10.
  3. Let the milk heat up slowly to 180ºF (30 minutes to 1 hour).
  4. Take the pot off the heat. Let the milk cool down to between 110-115ºF (~1 hour).
  5. Spoon 1 tbsp. of plain yogurt into your jar. Pour 1/4 cup of hot milk over the yogurt and stir to dissolve. Pour in the rest of the milk, stir, and put the lid on.
  6. Fill a large bowl with hot tap water that’s 110-115ºF, i.e., hot but not scalding. Place the jar into the bowl, cover it with towels, and tie a belt around it to keep it warm.
  7. Let the milk ferment for 4-24 hours, refilling the hot water every 6-8 hours. The longer you leave the yogurt, the thicker and tangier it will be.
  8. Take out the yogurt jar and put it in the fridge to chill and firm up a little bit.


  • If you’re going to make yogurt regularly, invest in a thermometer so you don’t have to do any guesswork. They’re between $10-20 online or in stores, and you’ll get a lot of use out of it.
  • Doubling or tripling the recipe is fine. Just use 1 tbsp. of yogurt per litre of milk.
  • Don’t try to use milk with <3% milk fat. You’ll probably get a runny, sad-tasting yogurt. Fat is your friend! You can even use 5 or 10% cream if you want amazingly yummy and creamy yogurt.
  • You can use a crockpot or slow cooker to heat up the milk. (Actually, that’s a really good idea. I think I’ll start doing that :P)
  • Heating up the milk should take between 30 minutes to 1 hour so that you gently unravel the milk proteins but don’t damage them. You can stir the milk and skim off the skin, but it’s not necessary.
  • If you’re not using a thermometer:
    • The milk is ~180ºF when you see little bubbles forming around the edges and surface of the milk, and steam coming up when you move the milk skin away.
    • The milk is 110-115ºF when you can put your finger into the milk and hold it there for at least 10 seconds. The milk should still be hot but not scalding.
  • To cool the milk faster, you can put the pot into another pot filled with tap water, and then stir it to cool it down in about 10 minutes.
  • Yogurt frozen into 1 tbsp. cubes works just as well as fresh yogurt.
  • Try not to disturb the fermenting milk for the first 4 hours or it might not set properly.


  • Yogurt is grainy — milk was heated up past 200ºF and started boiling, which damaged the milk proteins. Make sure to take the pot off the heat before the milk boils.
  • Yogurt is runny — milk didn’t culture for long enough or at a warm enough temperature, or milk was too hot when it was poured over the yogurt and killed the cultures.
  • Yogurt is gummy/slimy — milk proteins didn’t unravel enough; once the milk hits 180ºF, turn the stove to low and try to keep the milk at 180ºF for about 10 minutes (but don’t let it boil).
  • Yogurt still tastes like milk — let the milk culture in the new, hot water for another 4-8 hours to get a tangier and thicker yogurt.
  • You forgot about the yogurt and left it out for longer than 24 hours — no problem, the yogurt should still be fine! It’s hard for bad bacteria to grow in the milk because they’re overwhelmed by all the good yogurt bacteria.
  • If your yogurt failed for whatever reason, you can still drink the milk. It’ll taste and smell a bit like yogurt, but it will still be perfectly edible and safe to eat as long as it doesn’t smell bad.

The first 2 or 3 times you make yogurt are the most nerve-wracking. Aahh, it’s almost reached 180! Aah, it’s 110 and I have to add the yogurt cultures now! Aah, is the yogurt ready yet? Why’s it still runny?? But you’ll quickly get the hang of the method and what the best settings and timings are for your own stove and pots. I’m so used to making yogurt now that it just fits into my normal kitchen schedule. I make it in the morning before breakfast, check it after lunch to see if the water is still warm, then pop the jars in the fridge after my evening snack. Simple!

I’ve had maybe 4 failed batches in the 4 years I’ve been making yogurt, probably because I didn’t let the yogurt ferment at the right temperature for long enough. The next step in my yogurt-making journey is to get some heirloom cultures so that I never have to buy yogurt again. The problem with store-bought yogurt is that it’s been cultured using only a few isolated strains of bacteria and can only be propagated (i.e., you use the previous batch to start the next batch) 4 or 5 times before the bacteria get sad and don’t work any more. Heirloom cultures on the other hand, have a whole bunch of diverse and robust strains that work together, and will stay healthy and alive batch after batch.

Here are some great articles that might help you out if something went wrong with your batch of yogurt, or if you want to learn more about the art and science of making perfect yogurt.


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