A yogurt-making primer
It hasn’t been that long since I posted here about yogurt-making, but it seems like this weekend there have been a number of posts to the Instant Pot Community on Facebook by new Instant Pot owners who are interested in trying it. So I thought maybe it might be timely for me to write about it.
My friend Ivy started making yogurt with her Instant Pot a year or two ago and recommended yogurt-making to me. I didn’t yet own any sort of electric pressure cooker. But, based on Ivy’s recommendation, I bought an inexpensive plastic yogurt-maker, which I used for a while until I ended up buying my first electric pressure cooker, which later stopped working and which I have since replaced with a genuine Instant Pot.
What’s the advantage of making your own yogurt? For one thing, it’s much less expensive. For another, you’re in complete control over the ingredients, the texture, and any flavor additions. And I just think it’s fun.
I’ll start by explaining how to make yogurt in the Instant Pot, but then I’ll add some alternative directions for those of you who haven’t gotten on the bus yet.
The process of making yogurt in the Instant Pot is the same whether you are making traditional or “Greek” yogurt. If you want “Greek” yogurt, you will start by making traditional yogurt, and then strain it afterward, which has nothing to do with the Instant Pot. That’s the only difference between the two.
Instant Pot makes three different classes of pressure cookers — the Lux, the Duo and the Ultra. Only the Duo and the Ultra have pre-set yogurt functions. You can find directions online for using the Lux to make yogurt, but I’m not going to get into that here.
Yogurt-making does not involve the pressure-cooking functions of the Instant Pot, so you do not need to use the normal Instant Pot lid. It’s much more convenient to use a glass lid. You can order an official Instant Pot accessory glass lid on Amazon, but it’s also OK to use any lid you already own that fits the pot. If you have an old round slow-cooker, check and see if that lid will work.
When I make yogurt, I start with about a pint of whole milk. I find that whole milk gives a good texture. You can certainly use 2 percent or skim, but keep in mind we won’t be using any artificial thickeners or stabilizers like the ones found in store-bought yogurt. To me, whole milk yogurt isn’t that extreme of an indulgence.
Pour the milk into the inner pot of your pressure cooker. Push the “yogurt” button twice, until you see the word “BOIL.” This is a misnomer — we will not actually be bringing the milk all the way to the boil. We will be scalding it, bringing it to about 178 degrees. This changes some of the milk proteins and yields a creamier final product. (I will discuss “cold-start” recipes, which skip this step, a little later.) Many homemade ice cream recipes also call for scalding, for exactly the same reason.
Put your glass lid on if desired. Occasionally, you will want to whisk or stir the milk, scraping the bottom (the milk tends to stick to the bottom of the pot). When I used to have to do this step on the stove, it required constant stirring to keep the milk from burning, but the temperature controls in the Instant Pot make that a little less critical. Occasional stirring is highly recommended, however.
While the milk is scalding, fill a sink or a large bowl with cold water, maybe adding a little ice. Make sure you have a thermometer handy. A candy-making or deep-fry thermometer will do; you can also buy a special yogurt-making thermometer on Amazon that has the two key temperatures highlighted.
Once the Instant Pot beeps, the scalding is done. Immediately press the “cancel” button so that the base unit can cool down. Remove the inner stainless steel pot and place it in the sink or large bowl, so that the ice water cools down the pot. Use the thermometer, and stir the milk as the pot cools. You are looking for the milk to cool down to 110 degrees. The temperature is important because if it’s too hot, it will kill the starter culture.
Once the milk has cooled to 110 degrees, pull the pot out of the cold water and set it on the countertop. Now is the time to stir in your starter culture. There are three options for this, although one of them is, by definition, not available the first time around:
- A few spoonfuls of store-bought yogurt. Look for the freshest yogurt you can find, and make sure it’s labeled as having “live and active cultures.” Plain, unflavored yogurt is probably best, and if you can get traditional yogurt instead of Greek yogurt that’s better as well, even if you’re making Greek yogurt.
- A few spoonfuls of your own homemade yogurt from your previous batch. When I make a batch of yogurt, the first thing I do is set aside this starter portion. If I don’t think I’m going to be making a new batch in the next week, I freeze the starter. It will keep in the freezer until it starts to get freezer burn.
- One packet of freeze-dried starter. I like having freeze-dried starter on hand; it’s not expensive, and in cases where your own homemade starter is unavailable (maybe a batch didn’t turn out, or maybe you forgot to set aside your starter), having the freeze-dried starter stashed away is a great option. Here’s the starter I’m currently using. You can also purchase starters with specific probiotics, or special starters for use with non-dairy milk, or what have you.
At the same time I add the starter, I usually add a little bit of powdered milk, a/k/a nonfat dry milk. This is completely optional, but some yogurt-makers think it helps with the thickness of the finished product. I would definitely recommend it if you’re using lower-fat milk.
Stir to make sure the starter and the powdered milk (if using) are thoroughly mixed in. Place the stainless steel pot back into the Instant Pot base. (Make sure the base has cooled off from scalding.) Put on the lid and press the “Yogurt” button once, so that a time appears on on the display. You can adjust this time to suit your own tastes and schedule. I would recommend at least 8 hours but I’ve used times up to 11 hours. I usually incubate overnight, and so sometimes the times are based on when I get around to setting things up and when I plan to get up and leave for work in the morning.
In general, longer incubation times lead to a thicker product, but also a tangier product. If you want a mild product, and don’t mind a softer texture, go with a shorter incubation time; if you want a firmer texture, and don’t mind a tangier flavor, go with a longer incubation time. (Remember that you can also control the texture by straining the yogurt later.) Also, different starters may give you a tangier or less-tangy product, so you can experiment there, as well.
Try to disturb the pot as little as possible during the incubation process. Don’t peek, try not to jostle, and never, ever stir.
At the end of incubation, take off the lid and see if the yogurt appears to be set. At this point, it’s the firmest it’s ever going to be — once you start stirring it, or moving it to another container, it’s going to break down. But when you take that first peek into the pot, it should be pretty well set up.
At this point, my personal custom is to move the entire inner pot, with the glass lid, into the refrigerator. I wait until after the yogurt has chilled to transfer it to another container or to strain it. But there seem to be other yogurt-makers who immediately transfer the yogurt to a smaller container, with no ill effects. If space is at a premium in your fridge, you may not have a choice but to pour the yogurt into a smaller container.
At this point, your traditional yogurt is done. If you want Greek yogurt, the next step is to strain it. Line a colander with either several layers of cheesecloth or with coffee filters. Place the colander over a bowl. Empty your yogurt into the colander (set aside your starter before straining). Place the whole stack, colander and bowl, into the fridge and let it strain until it’s the desired consistency. If you like, you can let it strain a long time and you’ll get yogurt cheese, which can be substituted for cream cheese in recipes.
If you go farther than you intended, it’s no problem; just stir a little bit of the whey back into the yogurt.
Do not throw away the whey that collects in the bowl. It’s loaded with nutrition. You can use it for baking, for making rice or quinoa, or (my favorite) as the basis of a marinade for chicken. (It’s similar to marinating chicken in buttermilk, another cultured dairy product.)
I have no problem with the two-step, scald-then-incubate process for yogurt which I’ve just described. But a lot of members of the Instant Pot Community have recently been raving about what’s called the “cold start” process. By using some specially-processed ultra-filtered, ultra-pasteurized milks, like Fairlife, they can skip the scalding step and go straight to adding the starter culture. It’s a matter of personal preference, I suppose. Fairlife is much more expensive than ordinary milk, which takes away some of the cost savings of making your own yogurt. Fairlife is also lactose-free — but, frankly, the yogurt-making process already reduces the amount of lactose in milk, and the straining process removes even more. If you’re interested in the cold start method, check the Instant Pot Community for more details.
If you don’t have an Instant Pot at all, you can do the scalding step on the stove. You’ll need to stir constantly to keep the milk from burning, and use the thermometer to check for the desired temperature of 178 degrees, which you’ll want to try to maintain for a couple of minutes.
Then, to incubate your yogurt, you’ll need a way of keeping the inoculated milk at about 110 degrees for a number of hours. Here are some options:
- A commercial yogurt-maker. The one I used to use cost $16 when I bought it on Amazon, but the price has gone up to about $25 since then.
- If your oven has a light bulb inside, I have been told that you can place your container of inoculated milk into the oven, with the oven off but the light on, and if you don’t open the door the temperature will be steady at about 110 degrees.
- Alton Brown, on an episode of “Good Eats,” recommends lining a bucket with an electric blanket set to “medium.” Place your container of inoculated milk into the bucket.
- I have also read that you can use a large cooler. Fill two empty milk jugs with the hottest tap water and place them in the cooler next to your container of inoculated milk. Close the cooler and leave it closed. This technique seems the most suspect to me, because it depends on factors like how hot your tap water gets and how well-insulated your cooler is.
Yogurt-making is fun and economical. Once you’ve made your yogurt, you can flavor it any way you like — jam or “fruit-only” spreads, granola, vanilla, honey or what have you. Hidden Valley Ranch makes a ranch dip mix specially formulated for use with Greek yogurt instead of sour cream, and that’s a healthy alternative to a tempting indulgence.
Try yogurt-making, and tell me how you like it.