How to Make Homemade Yogurt

Why you'll love it

Knowing how to make a lot of your kitchen staples can be a very useful skill to know, especially if you are working on a budget. It is also great if you love trying out new things, want a fun weekend project, or like being able to know exactly what is in your food. For me, one of the most compelling reasons is just how satisfying it is knowing you were able to make your own homemade yogurt just like making your own brioche or ciabatta at home. It can give you a serious sense of accomplishment. 

You also never have to worry about the grocery store running out of your favorite yogurt flavor. If you save a bit of your homemade yogurt before adding in your favorite flavors, you can reuse it to make more when you are running low.

If you want to make your own yogurt, you have a few different options. You can use a yogurt maker and yogurt culture, or you can use your favorite plain commercial yogurt with milk and the tools you have at home. This homemade yogurt recipe uses the latter. We use starter yogurt from the store and no special equipment. There are even instructions on how to make the perfect yogurt without a kitchen thermometer and using your five senses instead. 

• Only 2 main ingredients: You only need milk and plain yogurt with live active cultures.
• No yogurt maker needed: I’ll show you how to make yogurt with basic kitchen tools.
• Multiple methods included: Use the stovetop, crockpot, or Instant Pot depending on what you have.
• Easy to customize: Keep it plain, add flavorings after culturing, or strain it into thick Greek-style yogurt.

Key ingredients

You only need milk and a starter culture to make homemade yogurt. For the starter, plain yogurt with live active cultures is the easiest option because it is inexpensive and easy to find, while powdered yogurt starter culture can be a good choice if you want a more controlled, consistent culture or do not have plain yogurt on hand.

• Milk: Whole milk gives you the thickest, creamiest yogurt, but 2% milk also works well. Lower-fat milk will make a thinner yogurt. Avoid ultra-pasteurized milk if possible, since it can be harder to culture consistently.
• Plain yogurt with live active cultures: This is the easiest starter option. Look for plain yogurt that specifically says it contains live and active cultures. Avoid flavored or sweetened yogurt because it can affect the flavor and texture of your homemade yogurt.
• Powdered yogurt starter culture: Use this instead of plain yogurt. Follow the package directions for how much starter to use with your amount of milk. This can be a good option if you want consistent results, are starting from scratch, or do not have plain yogurt available. Freeze-dried starter cultures are easily found online with enough for several fresh batches.

Equipment you’ll need

You do not need a yogurt maker to make homemade yogurt, but a few basic tools make the process easier.

• Heavy-bottomed pot: This helps heat the milk evenly and lowers the chance of scorching.
• Instant-read thermometer: Optional, but helpful for checking when the milk reaches about 200°F and when it cools to 110 - 115°F before adding the starter.
• Whisk or spoon: Use this to mix the starter smoothly into a small amount of warm milk before adding it back to the pot.
• Lid, towel, or blanket: Covering and wrapping the pot helps keep the yogurt warm while it cultures.
• Mason jars or airtight containers: Use these for storing the finished yogurt in the refrigerator.
• Cheesecloth or fine-mesh strainer: Optional, but useful if you want thicker Greek-style yogurt.

For incubating the yogurt, you can use an oven with the light on, a towel-wrapped pot, a slow cooker, or an Instant Pot. The goal is steady warmth, not high heat.

How to make: 3 methods

The original recipe for making homemade yogurt uses no special equipment, with notes on how to use minimal tools that will help you. I have also included instructions for using a slow cooker or a pressure cooker if you would like to try experimenting with one of these methods - luckily the same basic process is used with each method. The method I use and prefer is the stovetop method. 

How to make yogurt on the stovetop

1. Add the milk to a heavy-bottomed pot and heat until the milk is scalding hot and steaming. It should be rumbling, but not at the boiling stage. Scrape the sides and bottom of the pot constantly to avoid the milk burning. 
2. Allow the milk to cool until it is comfortable to the touch - about 110F. Take a cup of the warm milk and mix it in with the yogurt, then stir the yogurt and milk mixture back into the rest of the milk. 
3. Cover the pot and keep in a warm, dry area for at least 6 hours, preferably overnight. 

How to Make Yogurt in a Crockpot

If you want to make yogurt in a crockpot, all you need is a bit of extra time. It is a slower process, but perfect for someone who wants to make double or triple the yogurt. 

1. First, you must heat the milk on low in the crockpot. This will take roughly 2 -3 hours. 
2. Then you turn off the heat and allow the milk to come down to the temperature of bath water. 
3. Mix some of the milk with the yogurt and then mix the yogurt mixture into the milk in the crockpot. 
4. Keep the crockpot off, but in a warm area 6-8 hours, or preferably overnight.

How to Make Yogurt in an Instant Pot

Luckily, there should already be a yogurt option on your instant pot which makes it easy to use, but the exact process may still be confusing. 

1. First, you need to add the milk to the instant pot and set the yogurt setting to boil (the valve should be set to sealing). 
2. Once it is finished, allow the yogurt to cool down to bath water temperature. 
3. Use some of the milk to stir into your yogurt, then add the yogurt to the milk. 
4. Now you want to set the instant pot to the normal yogurt setting (the valve should be set to sealing or venting). Your timer can be set for 8 - 12 hours, depending on how tart and thick you like your yogurt.

The science behind making yogurt

Yogurt is made when live cultures ferment lactose, the natural sugar in milk, into lactic acid. The classic yogurt cultures are Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. As they produce lactic acid, the pH of the milk drops, giving yogurt its tangy flavor and helping the milk proteins form a soft gel.

Heating the milk first is one of the most important steps. Bring the milk to about 180–200°F. This helps reduce unwanted microbes and denatures beta-lactoglobulin, one of the main whey proteins in milk. We want this to happen because denatured beta-lactoglobulin can interact with casein proteins, helping the yogurt set into a smoother, thicker, more velvety texture.

If you are not using a thermometer, look for milk that is steaming heavily with small bubbles around the edges of the pot. It should look hot and active, but it does not need to come to a rolling boil.

After heating, the milk needs to cool before you add the yogurt starter. If the milk is too hot, it can weaken or kill the live cultures. Aim for 110–115°F, or milk that feels warm like bath water if you are not using a thermometer.

During incubation, the cultures keep working. The yogurt needs a warm, cozy environment, but not a hot one. Think warm room, oven with the light on, or a towel-wrapped pot that feels gently warm to the touch. A warmer environment helps the yogurt set faster, while a cooler one takes longer. The longer yogurt incubates, the more lactic acid develops, which makes the yogurt tangier.

Expert tips

• Choose a starter you like: The flavor of your homemade yogurt will be influenced by the plain yogurt or starter culture you use. Choose a plain yogurt you already enjoy, and make sure it contains live active cultures. I usually use plain Greek yogurt such as Fage or Oikos as my starter, but any plain yogurt with live active cultures can work.
• Use higher-fat milk for thicker yogurt: Whole milk makes the thickest, creamiest yogurt. 2% milk also works well, but lower-fat milk will be thinner.
• Cool the milk before adding the starter: Milk that is too hot can weaken or kill the cultures. Let it cool to 110–115°F before mixing in the starter.
• Mix the starter with a little milk first: Whisk the yogurt starter with about 1 cup of warm milk before adding it back to the pot. This helps it disperse evenly for a smoother texture.
• Keep the yogurt warm and undisturbed: Steady warmth helps the cultures work properly. Avoid moving or stirring the yogurt while it sets.
• Incubate longer for tangier yogurt: The longer the yogurt cultures, the tangier it becomes. Start checking around 6 hours, then continue incubating if you want a thicker or more tart yogurt.
• Do not throw away the whey: A little whey on top is normal. Stir it back in for thinner yogurt, strain it out for thicker yogurt, or use it in baking in place of water, milk, or buttermilk.
• Save some yogurt for your next batch: Reserve ½ cup of plain homemade yogurt before adding sweeteners or flavorings. Use it within the first week for the strongest cultures
• Use visual cues if you do not have a thermometer: Heat the milk until it is steaming heavily and small bubbles form around the edges. It should be very hot, but it does not need to reach a rolling boil. When cooling the milk, the milk should feel warm like bath water. If it feels hot enough that you would pull your finger away, it is still too hot for the starter.
• Do not overheat during incubation: More heat is not always better. If the yogurt gets too hot, it can weaken the cultures or affect the texture. Aim for steady warmth rather than direct heat.
• Start fresh every few batches: Homemade yogurt can be reused as starter, but it will not stay equally strong forever. After about 3–5 batches, or sooner if your yogurt becomes thin, slow to set, unusually sour, yeasty, or off-smelling, start again with fresh plain store-bought yogurt with live active cultures or a freeze-dried starter culture.
  

Storage

I recommend pouring your finished yogurt into mason jars with lids that are screw on finger tight. You can use smaller jars for single servings as long as you can get an airtight closure. Keep the yogurt in the back of the refrigerator to keep the temperature consistent. 

Adding sugars and fruits will decrease the freshness of the final yogurt. Plain yogurt should last two weeks, but if you plan on using the yogurt you made to make a new batch, you need to do it within the first week to ensure the cultures are strong enough.