< beginnings of a home dairy >

Let's talk about yogurt a little, friends. As far as I'm concerned, yogurt is the substance of life. We eat it for breakfast at least twice a week, but we also have it for snacks, use it in baked goods, use it in a dessert, serve it instead of sour cream when we have tacos for dinner, the possibilities are endless in my mind. But it gets expensive. Really expensive. Especially if you're trying to avoid synthetic hormones and antibiotics in your dairy. So a couple of years ago I started making my own yogurt, with very inconsistent results. One day it would be perfect, and the next it would be a curdled mess. But then about a year ago, I remembered that a good friend of mine had given me her old 2 quart maker, so I ventured out into the abyss that is my garage and miraculously dug out the box that it was in, and disinfected it and went to work. And it's completely changed my life. Yogurt couldn't possibly be simpler or more cost effective. (I make 1 gallon of organic yogurt every other week for $6! When I strain it for Greek-style yogurt, it ends up being about 3/4 gallon for $6. Where else could you buy that much yogurt for that cost?) Especially with the right tools. But I'm assuming not everyone has a generous friend who gives you a $50 piece of equipment for only one use, so I'm going to explain the whole process using your average-equipped-kitchen materials.

Basically, it boils down to a few simple steps. But knowing why we do these steps is pretty important to your success, I think.
First, we heat the milk (0%~whole and anything in between, but if you know me I never use lowfat, so I always make whole milk yogurt) over low heat to 180°F to kill any bacteria that will interfere with the culturing process that we're trying to control. It's important that you don't mess with the milk at this stage. No stirring. So when I say low heat, I mean very low. Yogurt cultures are persnickety this way and won't like to be bothered. And though you haven't added them yet, it's like they know somehow. 
Let it cool back down to about 120°F. Safer to err on the side of too cool than too hot here. 100°F~110°F is the ideal temperature for the live active cultures to work. Too cool and it could take days. Too hot and they'll die and your yogurt will curdle.
Once cooled to just under 120°F, gently stir in the starter with about 1/4 of the warm milk. The starter will be your favorite brand of PLAIN yogurt clearly labeled "live and active cultures". I like a tangy Greek yogurt, so I started with with a true Greek cultured yogurt. But choose the ones you like, and if you love the result, you can keep reusing it indefinitely. Just store a little bit of each batch for the next.
Once well mixed, pour your mixed, tempered yogurt to the container you'll be incubating it in, add the rest of the warm milk, and give it another gentle stir, and then you incubate it in an environment that will maintain a temperature of about 100°F~110°F for 6~24 hours, depending on the result you want. 6 hours will give you a thinner, more mellow yogurt flavor, 24 hours will be completely free of lactose (which might be good for some of you) but very strong. Almost ... gamey. I have lactose issues (along with the other 99% of Asians that do), so I go somewhere in between. Around 12~18 hours. I want as much lactose gone as possible, but the 24 hour yogurt just doesn't work for my palate. At this point, if you want that thick, Greek-style yogurt, You can line a sieve with cheesecloth or muslin over a bowl and drain for 4~6 hours until your desired consistency is reached.
Relatively simple, right? The incubating part might be a little daunting, but there are ways to make it work. This time, I poured the contents into a 1/2 gallon mason jar, wrapped it in foil and a quilt, and placed it in my oven. I had heated my oven to about 100°F and turned it off before adding my yogurt. It turned out beautifully. Some people who are lucky enough to have an oven light that you can turn on and off like to just leave the light on. The heat from the light bulb in there is apparently enough to maintain a warm environment.

Other options for incubating include placing your container in a cooler and adding a few glasses full of hot water next to your yogurt. Or placing it in a preheated and turned off slow cooker. Or if you're doing it in the Summer, just leave your yogurt in the sun, believe it or not. I liked the oven, though, since it seemed reliable. Of course I prefer my yogurt maker since it's designed to maintain the perfect temperature. So if you love the results, and I think you will, you might want to someday invest in a yogurt maker.

Tools that are necessary or that I recommend:
candy thermometer or digital thermometer with an alarm. I bought mine at IKEA and love it
large, non-reactive, heavy-bottomed pot
cheesecloth or fine muslin
fine mesh strainer (sometimes when you heat up the milk, there will be little pieces. You want to start with a smooth base)
Metal spoon for stirring
large container for incubating (preferably glass. non-reactive, doesn't give off flavor, and see-through!)

Let's get started, shall we?

Homemade yogurt
makes 1/2 gallon, easily halved or doubled
1/2 gallon of good quality, homogenized milk
3 tablespoons (1/4 cup and 2 tablespoons) of your favorite plain yogurt with live and active cultures

  1. In a large, non-reactive, heavy-bottomed sauce pan or pot, heat the milk over low heat until it reached 180°F (82°C). Don't stir the milk.
  2. Once heated, let the milk cool to 120°F (48°C).  You can speed up this process by placing your saucepan inside a large bowl full of ice water, or transferring your milk into a small bowl that will fit inside a larger bowl full of ice water. Taking care not to get any water into the milk.
  3. Once the milk has cooled down to 120°F (or a little lower), put the yogurt in the container you will be using to incubate it in. Pouring through a fine mesh strainer to catch any bits or the skin that has formed, pour about 1/4 of your milk into your container with the yogurt. Stir gently with your metal spoon.
  4. Once incorporated, add the rest of the milk mixture through the strainer as well. Give it another gentle stir, cover, and incubate for 6~24 hours, depending on desired consistency. (Suggested incubation methods above)
  5. If you want a thick, Greek-style yogurt, line a sieve with a piece of clean, damp cheesecloth or muslin, place it over a bowl and pour in your yogurt. Let it strain for 4~6 hours until desired thickness is reached.
The coolest thing about this is that once you make it the first time, you never have to buy yogurt again! You can just reserve your 6 tablespoons from your last batch and use it when you're ready to make your next batch. So from now on, your gallon of half gallon of yogurt will only cost you the price of the milk. Not bad, right?


Indiana Haffners said...

My problem has always been kids eating it all and then I have to buy my starter all over again! Save the 6 tbs first! :) Where did you get your incubator? I use my crockpot wrapped in a towel in the oven which isn't very exact.

Indiana Haffners said...

Uhm...let's call me a visual learner and pretend I can't read or I would have read where your yogurt maker came from. :) Thanks for humoring me.