Maybe everything I know about making homemade yogurt

A little about me: I cook a lot, mostly dinner at home for my family and friends but sometimes for massive parties of upwards of 200 people. I’ve been doing sous vide cooking since 2010. I run a food blog called Unselling Convenience (also @unsellingconvenience on Instagram if you’d rather follow along there), which is mostly an inspiration board and memory database of things I’ve enjoyed cooking and probably want to cook again. I believe that shortcuts are great, but not at the expense of quality. I administer the Everyday Sous Vide and Instant Pot Love groups on Facebook. I’ve been writing about food for a few decades and have started collecting the good stuff at https://counter.kitchen. If you buy something from one of the links, I probably get a small commission which won’t even come close to defraying the amount of money I’ve spent on these things over the years but which will make me happy anyway.

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I like yogurt. One of my favorite snacks to make when I don’t know what I want is a bowl of yogurt with fresh berries, raisins, granola, and a little honey. I like to strain the yogurt so it’s a little thicker, and the strained whey is useful as a buttermilk substitute.

Raisins are supposed to taste like grape juice, and homemade ones do.

There are a lot of ways to make yogurt. You can do it just with a pot and minimal equipment. Sous vide works well, but I find it a little fussy for large quantities. We go through about 6 quarts of yogurt a week (mostly from our teenagers making smoothies), and the Instant Pot makes this very easy and mostly hands-off.

Economically speaking, making yogurt takes time, but around these parts, a quart of high quality yogurt costs more than a half gallon of the best milk I can find. So while it takes some time and a little bit of attention, it is massively cheaper to make my own.

The overall process is very simple — heat milk to a high enough temperature to kill any bacteria present, cool it to a point where it won’t kill the bacteria you introduce, mix in a starter culture to inoculate it, and then let it sit at a favorable temperature to develop the cultures. The longer you let it sit, the more sour it will get. In the initial stage, cooking to 180F is typically recommended. I think it’s worth it to hold it above 190F for 20 minutes which denatures the proteins somewhat and makes a thicker end product even before straining.

Temperature control is important. You want to heat it sufficiently to pasteurize, and you need to cool it sufficiently that it doesn’t kill your starter. You can use a regular thermometer, but I like to use the ChefAlarm from Thermoworks (the same company that makes the Thermapen), which conveniently lets you set high and low alarms for a temperature range.

For starter, you can use any existing yogurt with live cultures. Technically, that can also be any homemade yogurt, but I’ve found that using a batch as the starter for the next batch doesn’t produce results that are as good as starting with commercial yogurt — the bacterial strains start to drift over generations. I buy a quart of good yogurt every few months and freeze a bunch of it in cubes to use for starters.

a little lemon curd is also nice

I use an 8 quart Instant Pot Pro, but most models of Instant Pot will work fine. If you’re using a ChefAlarm or other continuous measuring thermometer, you will also want the glass lid (available in different sizes) which has a hole you can stick the probe through.

My detailed steps to make yogurt in the Instant Pot:

1. Sterilize the pot by putting about half an inch of water in the bottom and putting on high pressure mode or sterilize (if available) for 1 minute, using the pressure lid. Let cool a bit, then pour out the water.
2. Add milk, switch to the glass lid, then use the yogurt boil (sometimes called pasteurize) mode until it stops, usually about 30–60 minutes depending on how much milk there is in the pot and how cold it was.
3. Somewhere in there, add the chef alarm temperature probe. If you’re using a ChefAlarm, set the high temp to 190F and the low temp to 105F.
4. When the boil mode is done, switch to slow cook mode high, and heat until the milk reaches 190F. If you have a sous vide mode on your IP, use that at a temperature of around 196F. The thermometer alarm will go off when it reaches temp. You can silence the alarm at this point.
5. Switch to slow cook mode normal and run for 20 minutes. If you were using the sous vide mode, just let it sit for another 20 minutes after reaching 190F. If you accidentally actually boil the yogurt or let it sit in the sous vide mode for a long time at this temp, that’s likely fine as long as you don’t burn the bottom and it still looks like milk. I’ve accidentally left it overnight at 190F and it was fine.
6. If you don’t have any fresh live culture yogurt, take a frozen yogurt cube or two out of the freezer and transfer to a small glass bowl to thaw. Reseal bag. If you use a vacuum sealer, don’t forget to put it back in the freezer right away (easy to get distracted, walk away, and forget about it so you end up with one giant block).
7. Remove the pot and chill in an ice bath in a larger pot, until the milk cools to 105F. The alarm will go off, but stir it and it may raise the temp again a bit and have to cool some more. Usually around 30–40 minutes depending on how much ice you use.
8. Once the milk is uniformly 105F, add the thawed yogurt or about 2–4 tbsp of live yogurt, and blend well with the stick blender to incorporate the starter and break up the fat globules. You can remove, clean, and put away the thermometer at this point.
9. Switch back to the pressure lid and set the machine for the yogurt regular mode, for between 24 and 99 hours. This will keep it at around 90F to culture.

After it’s done, transfer to an airtight container and store in the fridge. I use these 3-quart food containers. If you want to strain it, let it chill in the fridge for a few hours first to solidify. Unstrained yogurt lasts several weeks, strained yogurt usually around a week, strained whey will last for several months.

thicker is better

Enjoy!

Feedback is welcomed! Leave a comment here, or find me @fields@hachyderm.io on mastodon or @unsellingconvenience on instagram or @spoilersinthread on bluesky or threads.