This post is part of my homemade basics series.
Making yogurt at home is surprisingly simple, and fun! With a few easy steps you can – literally overnight – transform a carton of milk into bowls full of delicious, creamy homemade yogurt.
My adventures in yogurt-making began a couple years ago after visiting my in-laws in India. The warm climate is ideal for fermentation, the process that transforms milk into yogurt, and in India you can make yogurt right on the countertop. Historically, yogurt was a useful way of preserving and storing milk in warm climates. Like many fermented foods (pickles, sauerkraut, buttermilk, miso, kimchi), yogurt has probiotics and a number of health benefits. It’s known to help with digestion, provides a ‘cooling’ effect when eaten with spicy food or in hot weather, and is easily digestible for those with lactose intolerance. The history of yogurt dates back as far as 9,000 B.C. and has been a staple in ancient Indian, Persian, Greek, Arabic and Turkish cuisines.
Yogurt has been made at home for many generations in India, where it’s also called dahi or ‘curd’. Store-bought yogurt is widely available, but some families continue the traditional method of making at home. Similarly, I can certainly find a very wide variety of yogurt and Greek yogurt at any grocery store, but I find there’s inherent satisfaction of creating this ‘homemade basic’ again and again from scratch. It’s easy to make large or small quantities, customize ingredients by using 2%, whole or organic milk, and tinker with flavour and consistency by experimenting with different starters, incubation times, and how the yogurt is strained afterwards.
It’s also significantly cheaper than store-bought yogurt. And with an abundance of affordable homemade yogurt at my fingertips, I’ve been more inclined to use yogurt as an ingredient. Aside from being a ready-to-eat breakfast staple, yogurt is a versatile ingredient that can be used for a variety of dips and side dishes (Arabic labneh, Indian raita, Greek tzatziki), yogurt-based drinks (Indian lassi, Turkish ayran, Arabic laban, Iranian doogh), and a base ingredient for Arabic/Levantine sauces and Indian curries.
Greek yogurt has become a particularly popular style of yogurt. The liquid from regular yogurt (called whey) is strained and discarded to create thicker, creamier Greek-style yogurt. Greek yogurt has a stronger tangy-sour taste when compared to regular yogurt and has higher protein content, making it a preferred health food. Its thicker consistency makes Greek yogurt a healthy substitute for certain higher-fat ingredients like sour cream.
Ingredients and Method
Milk is the primary ingredient in yogurt and the only real ingredient aside from active bacterial cultures. I’ve had success by using higher-fat milk, 3.25% whole/homogenized milk. The taste and consistency of using whole milk has been much more satisfying than using partially skimmed 2% milk.
Active bacterial cultures are added to warmed milk in order to start the fermentation process. There are a number of yogurt starters on the market to experiment with, but personally I’ve found it most convenient to use store-bought yogurt as a starter. In Canada, my preference has been PC Greek Yogurt or Liberté brand yogurt, which have resulted in smooth, mild-tasting homemade yogurt. However, any yogurt with active/live bacterial cultures can be used to make your own homemade yogurt.
Incubation and fermentation is the process where the active/live bacterial cultures spread from the yogurt starter across the remaining milk. The fermentation process needs a relatively stable temperature of about ~110°F. Fermentation can still happen at lower temperatures but the incubation time may be longer. So, the challenge for an aspiring yogurt maker is finding a suitable environment in your home that allows for ~10 hours of incubation.
I’ve had success with two different incubation methods:
1) After mixing the yogurt starter with warmed milk, cover the saucepan with a tea towel and keep it overnight in an oven with the interior light on. Since the lowest temperature of most ovens is too warm (170°F), which would kill the live bacterial cultures, the incandescent bulb in many ovens provides enough warmth for fermentation – however, success may vary from oven-to-oven.
2) Using the Yogurt (“YOGT”) setting on the Instant Pot. The YOGT setting maintains a temperature between 97°F – 110°F, according to the company. I’ve found that the Instant Pot is convenient for making yogurt and is now my go-to method. The settings allow you to set the incubation time, to 10 hours for example, making it more convenient than the oven method.
There’s a variety of incubation methods that could be worthwhile exploring. Some people use heating pads, warm sink-baths, slow cookers, or dedicated yogurt makers to incubate their yogurt.
Straining yogurt is needed to make Greek-style yogurt. There are several ways to strain your yogurt: cheesecloth (traditional method), muslin cloth, Greek yogurt strainer, bouillon strainer, coffee filter, or thick paper towel. I prefer using a plastic colander lined with a couple of basket coffee filters. This, I find, is the fastest and easiest method for cleanup. The basket coffee filters (ie. not the smaller cone filters) are a good size for straining up to ~4 cups of yogurt. Place the colander and filter over large bowl or saucepan to collect the liquid whey. Straining yogurt can be done in the fridge.
4 cups milk (3.25% whole milk is preferable)
1/4 cup store-bought yogurt (with live/active bacterial cultures)
Warm milk in a saucepan on low-medium heat, stirring often to avoid burning. The milk should be warmed to a temperature of ~195°F (or near-boiling) to denature the whey protein. This allows for thicker, creamier homemade yogurt.
Once the milk has reached near-boiling point, remove from heat until the milk cools to ~115°F. To speed up this process, cool the saucepan in an ice bath for ~5 minutes. You can estimate the temperature by waiting until the milk is “warm to the touch”. Discard any film that collects on top of the milk.
Scoop or pour ~1 cup of milk from the pan into a separate bowl and gently whisk 1/4 cup of yogurt until fully dissolved. Then, add the milk-yogurt mixture to the saucepan and stir gently.
Allow the yogurt to incubate for 8-10 hours at warm temperature (~110°F) (see Incubation methods section above). The incubation time will depend on a number of factors: type of milk, type of starter, incubation temperature, and desired consistency.
To stop the fermentation process, remove from heat, allow to cool, and then store in the fridge. The yogurt can be consumed at this stage. However, if you prefer thicker Greek-style yogurt, the liquid whey must be strained to reach your desired consistency.
Strain the yogurt in the fridge using your preferred method (see Straining yogurt section above) until the yogurt reaches your desired consistency. I typically strain Greek yogurt for ~12 hours in the fridge. When complete, remove yogurt from colander, discard the liquid whey, and store in containers in the fridge.
Depending on the milk and yogurt starter used, homemade yogurt should last at least 2 weeks in the fridge.
Also: Once you’ve made homemade yogurt, you can easily make labneh!