How to Make Homemade Yogurt

There are several ways to boil an egg. But after much research, I’ve concluded that there is basically a single path to making homemade yogurt without a yogurt maker.

Sure there are differences in recommended timing and equipment, variations in the temperatures recommended for each step, and varying advice on how to do each of the steps. But after comparing 6 sets of directions, I found that they all used the same 4 steps:

1. Heat the milk
2. Cool the milk
3. Add the yogurt and cool it some more
4. Refrigerate the final product before eating it.

These directions reference posts on yogurt making from SeriousEats, TheKitchn, Epicurious, NPR, The Frugal Girl, and MakeYourOwnYogurt.com, and my own experiences making yogurt.

How to Make Homemade Yogurt

Ingredients (For 2 quarts of yogurt)  

• ½ gallon (2 quarts) of milk Some recipes insisted on whole or 2% milk and one said it didn’t matter. I used whole milk.
• Between 2 tablespoons (1 ounce) and 16 tablespoons (8 ounces) of yogurt with live cultures. (Check the ingredient label on your yogurt. If it contains live cultures, it will say so.) Yes, I agree that’s a huge variation in the amount of “starter” called for.  

Equipment

• A large heavy bottomed pot (with top if you want to cool it in pot)
• A whisk or large spoon
• An digital or candy thermometer that clips onto the side of a pot
• Small bowl or cup (optional)
• Ladle/funnel (if you use jars for cooling)
• Cooler, thermos or other container for cooling (optional)
• Glass container(s) to hold the yogurt (optional)

Preparation

• Heat the milk in the heavy bottomed pot until it reaches somewhere between 180 degrees F and just below boiling. (Milk boils at slightly higher temperature than the 212 degree boiling point of water.) The majority of the versions I consulted directed heating to 180-195 degrees F.
• Let the milk cool back down to 110 – 120 degrees F.
• Add the yogurt. TheKitchn version suggests thinning the yogurt with a cup of the warm milk before adding it to the large pot of milk, whisking or stirring gently until fully incorporated. The Epicurious recipe warns against stirring too vigorously.
• Cool the yogurt down very slowly for anywhere from 3 to 12 hours. All the recipes require a draft-free environment that keeps the cooling from happening too quickly. For example, some direct putting the pot, covered, into an oven heated and then turned off. Others suggest putting the yogurt into clean glass canning jars with lids in a closed cooler with 120 degree water surrounding the containers (but not up to the lids), or leaving the milk to cool inside a thermos. One version even suggested putting the pot on a cutting board, covering it with a heating pad set to a medium setting, covering it with a towel and leaving it that way for 7 hours. The various versions agreed that the longer you leave the yogurt cooling, the thicker and tarter it gets. (To make Greek yogurt, you have to strain it after refrigeration; but some “regular” yogurts are almost as thick as Greek.) If you put the yogurt in jars before cooling the recipes call for sterilizing the jars or putting them through a sani-cycle on a dishwasher. 
• Refrigerate the yogurt for at least a minimum 2 hours according to one recipe or 7 hours according to another.

Here are two links for troubleshooting suggestions if your yogurt-making isn’t working out, from MakeYourOwnYogurt.com and Frugal Girl.

My Experience Making Yogurt

• I used whole milk and 6 ounces of nonfat yogurt.  I did smile at that combination. The whole milk yielded a rich, delicious final result, but routinely I would probably opt for 2% or nonfat. Using nonfat starter did not appear to cause a problem. 
• I was surprised at how quickly refrigerated milk warmed to the right temperature. On a gas range with medium-high heat, the milk in my Le Creuset pot got to 180 degrees F in just 10 minutes.

• I cooled the heated milk down by putting my pot in the sink with cool, but not cold water. Again, it was fairly quick – the milk to cooled to 110 degrees in 15 minutes. (Note: I got called away and by the time I got back, the milk was slightly below 110 degrees.  Epicurious said I could reheat to bring it back to 110 degrees, so I did.)

• For incorporating the yogurt, I followed TheKitchn’s suggestion to pull out a cup of warm milk, whisk the yogurt into that and pour it back into the pot. That was good advice.
• For the second cooling, I tried both the covered-pot-in-the-oven method and the jars in water method. I didn’t have a cooler for the jars, so I improvised.  On the oven batch, I went fancy; using the 100 degree F bread proofing setting on my oven. 

• I took the 2 batches out after 5½ hours. They were thin, but definitely on their way to yogurt. Surprisingly, my improvised container-and-towel method yogurt had a firmer temperature than the pot-in-the-oven batch.

• I refrigerated the yogurt overnight; in the morning, the container-and-towel batch was thicker and creamier. Both batches required stirring to get the lumps out, but they had nice texture after stirring and weren’t too tart. I have no idea why the difference in texture. 
• I strained the thinner, pot-in-oven batch to make Greek yogurt. (It’s easy and takes only an hour or so.) 

The Pros and Cons of Making Your Own Yogurt

(Note that the ingredients you use affect the taste. Whether your homemade tastes better than any particular brand will be depend on your ingredients as well as your tastebuds.)

Pros 

• It is less expensive than store-bought (but not by much unless you make Greek yogurt)
• You can control the taste and consistency, especially once you’ve tinkered with your preparation steps.
• Ingredient control – you know exactly what milk and yogurt culture went into the final product.
• If you eat a lot of yogurt, once you get the hang of yogurt-making, the routine is simple.

Cons

• It takes about an hour to prepare and do the cleaning and cooking steps before the yogurt cools in the pot or in glass containers. (The old time vs. money trade-off.)
• Unless you eat a lot of yogurt, you don’t save much money unless you make Greek yogurt, in which case you save more because of the significant price disparity between regular and Greek.

Would I make it again? Yes, especially if I can mix with my favorite granola. This yogurt tasted good enough and was easy enough to encourage me to experiment, trying 2% and skim milk and various starters. However, we don’t eat enough yogurt in my house to justify making this a regular routine.

How about you? Are you going to try making homemade?