Wednesday, June 4, 2008

yogurt redux

Ever since we got interested in making yogurt (again, thanks to inspiration from Mama Monster), we've found a few different methods that all seem to work. And since then, when I mention that we've started making our own, the next thing I usually hear is, "How?"

Making yogurt is kind of a ridiculously simple but fascinating process. Methods vary, but they always involve the same basic steps:

  • Heat milk (of any kind: whole, skim, soy, goat, whatever you prefer) to about 185°F to kill any bad bacteria, but not so hot that the milk curdles
  • Cool it to about 110°F - 120°F (opinions vary, but this is about the temperature that will get the yogurt cultures all happy)
  • Add good bacteria (active yogurt cultures) in the form of a couple tablespoons of yogurt from a previous batch, or from store-bought plain yogurt
  • Somehow keep the milk warm for 8 - 12 hours so the cultures can do their thing. In this warm environment, they begin to reproduce, eat the lactose (dairy sugar) in the milk and release lactic acid, which is what makes yogurt taste sour. The increase in acidity also makes the milk thicker. Once the yogurt is chilled, the cultures slow down and go back to sleep. Wow! Science!
How you heat the milk, how you check the temperature, and how you keep the milk warm are the variables, and they depend on what you have or what you are willing to buy.
  • The easiest option for many people is to buy a home yogurt maker. It takes the guesswork out of the heating and cooling, and automatically maintains the optimum temperature for you. It does use electricity, but if you don't have the time to be watching over a pot of milk, it might be a worthwhile investment.

  • If you have an electric heating pad, try the detailed instructions at MakeYourOwnYogurt.com. We used this method for a while, even though we don't have a heating pad. We just piled a bunch of towels over the pot of milk to keep it warm.

  • If you have a microwave and a Thermos, try Bean Sprouts' method. Melanie also includes a handy troubleshooting list and an extra step to make thicker Greek-style yogurt.

  • Just wing it. I recently showed up for a workshop with the PermiBus folks on their Skills for a New Millennium tour, prepared to make a water jacket and use a candy thermometer like in the MakeYourOwnYogurt directions. While a candy or dairy thermometer is a handy thing to have, it's probably not essential. The people at the workshop suggested a couple of rough measures to tell if your milk is the right temperature: When it starts to froth and form a skin, it's hot enough. When it's bath temperature (i.e. hot, but not so hot you'd scald yourself), it's cool enough to add the cultures. They made the yogurt directly in glass mason jars, which eliminates having to put it in a storage container once it's done.
So there are some options. The way we've been doing it recently is heating the milk directly in a pot on the stove, putting the starter yogurt at the bottom of a couple of pre-heated 24-ounce mason jars, pouring the milk in the jars, stirring and closing the lids tightly. Then we roll up the jars in towels and leave them all day or overnight. When it's done, we stir vigorously and stick the yogurt in the fridge. The end!

Homemade yogurt is thinner than most store-bought yogurt, because the manufacturers usually add a thickener like pectin or gelatin (if you use a store-bought yogurt as a starter, make sure there aren't any such additives; just milk and active cultures). If you want to thicken your yogurt, use Bean Sprouts' straining method (link above).

Why make your own yogurt?
  • It's cheaper (ours works out to be about half the price of store-bought)
  • No waste; no plastic containers piling up
  • You know exactly what's in it
And it's delicious! I like it as a snack with fruit or jam, for breakfast with muesli, or in smoothies (hello, frozen strawberries). You can also use it as a substitute in recipes that call for buttermilk. Or make a sort of raita by mixing a few tablespoons with a pinch of salt and some chopped fresh herbs like mint, chives, or if you're into that kind of thing, cilantro. Great as a condiment with spicy foods.

Go forth and multiply some bacteria!

4 comments:

Melanie Rimmer said...

Thanks for the link. The Greek Yogurt article is by far the most popular I've ever written. I hope your readers find it as useful as mine do.

maria said...

thanks, melanie! your post was one of the first that got me all fired up about yogurt. i think your greek yogurt tip is especially valuable, because that stuff is so expensive in the store!

Amanda said...

Making yogurt is definitely on my list of habits to create this summer. I hear tell that you should save the whey that drains off when making Greek yogurt (or yogurt cheese) to use in cooking.

Anonymous said...

The best yogurt we ever had was when we had a milk cow and used unhomogenized unpasteurized raw milk. We would get yogurtized cream at the top of each gallon jar, and it was scrumptious, especially with a little pure maple syrup mixed in - maybe even better than ice cream. As I recall, sometimes it came out runny but sometimes it thickened up just as much as Dannon. I think we only needed about 1 T. of yogurt for culture per gallon of scalded-and-cooled-down milk. If you ever have access to raw goat's or cow's milk, I strongly recommend that you get some to use for yogurt. And Amanda is correct, the whey is useful. If you make your own bread, you can use the whey instead of water. The yogurt can be used instead of milk and lemon juice/vinegar in muffin recipes, too.
-Lorie