Today I’m going to show you how to make yogurt using the cold-start method both with and without an Instant Pot.
After making yogurt the traditional way for over 11 years, I decided to experiment. I’m a little late to the cold-start yogurt party, but I’m having fun with it. I think you will, too.
I remember when I first dipped my toes into the world of homemade yogurt over eleven years ago. After reading lots of blogs, I was confused and frustrated with all the different instructions. It was hard to know who to believe.
After much research and experimentation, I’m cutting through the myths and misinformation about cold-start yogurt. This post will teach you how to make a successful batch of cold-start yogurt in your own kitchen.
Don’t worry if you’ve never made yogurt before. This post will make it easy for pros and beginners alike. Be sure to take a look at the FAQ below for answers to basic and not-so-basic questions.
What is different about this method?
You don’t heat the milk before incubation. As a result, you don’t need a cool-down period.
You just shaved at least an hour and a half off the time it will take to make your next batch of yogurt.
In the simplest terms possible, that is the only difference!
There is a catch!!
You must use ULTRA-FILTERED milk. Not ultra-pasteurized milk. Not organic milk. Not regular milk. Not milk from happy cows eating grass on a hillside in California.
Sometimes two or more of these labels will co-exist on the same bottle of milk. As long as one of the labels is ultra-filtered, you are good.
Frequently Asked Questions:
Ultra-filtered milk goes through a filtering process to remove most of the lactose along with a lot of the sugar. Filtering also concentrates the protein.
The average cup of regular milk contains 8 grams of protein. Fairway and other brands boast of 13 grams of protein in 1 cup of milk.
Ultra-pasteurized milk is heated to a high temperature (280˚). The process results in longer storage capabilities. However, the amount of protein remains the same. You can’t make spoonable yogurt without freeing up more proteins.
In the end, the more protein available, the thicker your yogurt will be.
(Be sure to read the next question and answer to get the bigger picture.)
The purpose of heating milk to 180˚F in the traditional method is to “denature one of the main whey proteins, lactoglobulin, which allows it to join in the mesh (instead of remaining inactive) and effectively increases the amount of protein in the milk that will be available to thicken the yogurt.”
In other words, heating before incubation is not to kill bacteria in the milk as some suggest. Hopefully, that has already been accomplished in the pasteurization process.
So yes. It is safe to make yogurt with pasteurized and ultra-filtered milk that hasn’t been heated before incubation.
Yes. I’m not sure how that name got started. Even with the traditional method, it’s not a good idea to boil your milk when making yogurt.
Diafiltered milk is another name for ultra-filtered milk. I have the impression this term is more common in Canada.
It takes less than 5 minutes to prepare your starter and milk. The rest of the time will be hands-off as your yogurt incubates (sits in a warm place). Think of a hen sitting on her eggs–sort of.
There is no exact time. The answer for you will depend on how tart you like your yogurt and the temperature of your incubation system. Mine usually sets in 5 hours at 100˚F. I prefer mild.
Some people like to incubate all night. Try it either way until you get the product you want.
The “starter” is what inoculates the milk and starts the process of making yogurt. It must contain little yogurt bodies (aka healthy bacteria) to do its job. It can be grocery store yogurt, homemade yogurt, or specially-formulated freeze-dried starter.
For the best chance at success, use very fresh unflavored yogurt. I’ll admit to using vanilla-flavored yogurt with sugar added in the past. It turned out OK.
No. Any unflavored yogurt with active cultures and no additives such as gelatin will work. Regular yogurt, Greek yogurt, organic yogurt…any of them are fine.
I like mine thick, too.
Strain it. The process is no different from straining yogurt made the traditional way. Read these posts for detailed instructions and ideas about straining: using a yogurt pouch or a large coffee filter.
An Instant Pot is super-easy if it is big enough to suit your needs. An oven you can set to 100˚F is big and easy.
Beyond that, you may have to get creative. I have collected lots of ideas from my readers over the years. You can read about them in this post about ways to incubate yogurt without a yogurt machine.
This is a hard question right up there with “When will I know he (or she) is the right one?” The answer is almost the same. Ha!
Experience is the best teacher–failure might be even better. But let’s give it a shot.
Uncover your yogurt without moving or jostling it. Yogurt babies do not like to be disturbed! Very gently shake the container. It should jiggle only slightly.
If it’s not ready, give it another hour or so and check again. If your yogurt still isn’t firm after additional incubation (total of 10 hours + or -), smell it.
If it smells OK, add more starter. A different starter would be even better. Stir well. Incubate again for 5-10 hours.
If that doesn’t work and it still smells fine, make smoothies. You could also try making ricotta cheese with your failed batch. It’s delicious and easy.
Yes, Regular milk contains 8 grams of protein per cup. Ultra-filtered milk averages 13 grams of protein per 1-cup serving. That means your finished cold-start yogurt will contain 13 grams of protein per cup.
If you like thicker yogurt and decide to strain it, you’ll get even more protein. In case you are a protein fanatic, check out this post for more ways to pump up the protein in your yogurt.
The general answer is two weeks. If it smells bad or you see any mold (usually pink), throw it out.
If you are a yogurt newbie, see a complete tutorial plus a video for the traditional method here. If you’ve never made yogurt before, check out Five Things You Should Not Do When Making Yogurt.
Ready to get started?
Preparing the “starter”
Use store-bought yogurt or homemade yogurt as a “starter.” If using a freeze-dried starter, follow the directions on the package to activate it.
Cold-start method without an Instant Pot:
Cold-start method with an Instant Pot:
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If you make this recipe and enjoy it, consider helping other readers and me by returning to this post. Leave a rating on the recipe card itself underneath the picture. Although always appreciated, comments aren’t required. Thank you for visiting! Paula
- 1-liter ultra-filtered whole milk (or use 2% or non-fat ultra-filtered milk)
- 1 tablespoon of yogurt (homemade or storebought)
- Whisk a small amount of cold milk into yogurt "starter" until it is smooth.
- Pour milk into Instant Pot or a large bowl such as a 2-quart Pyrex pitcher.
- Stir thinned "starter" into cold milk.
- If using an Instant Pot, position the lid on top and push the Yogurt button. Time should be 5-9 hours according to the level of tartness you prefer. If you are doing overnight, set the pot to finish when you wake up.
- If using a bowl, place the pitcher in a warm environment. Keep the temperature at a constant 100-110˚F level.
- Check yogurt after 5 hours. When yogurt sets, it will look like Jello with only the slightest jiggle. If you're not sure, dip out a spoonful to see if the yogurt will stand up on its own. If you want a firmer set, return it to the warm place without jostling and check again later. Once you stir the yogurt, incubation is over. Remember that it will become somewhat thicker when chilled.
If you want Greek yogurt, strain the yogurt when the incubation period completes. You can strain yogurt on the counter for a couple of hours. It's safe. If you feel more comfortable (and have the room) set your strainer in the refrigerator.
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