February 24, 2011 by Leah
Hi! Thanks for stopping by. Here’s an update (as of August 5, 2011) to the following post.
The principle of yogurt making is very simple: take some milk, heat it to kill the bacteria that’s already in it, cool it just enough so that it won’t harm the bacteria you plan to introduce, introduce said bacteria, and allow the whole shebang to ferment for a few hours at a friendly temperature. Voila. Creamy deliciousness. That said, the practice of making yogurt varies a lot from person to person.
This NYTimes article got me interested in yogurt-making last summer. I made my first batches of yogurt in a thermos, and while it worked, it wasn’t ideal. Eventually I came across the water bath method (I can’t remember where) and this has worked really well for me.
What you need:
- Milk that has not been ultra-high pasteurized. It will say UHP on the label. Horizon Organic and other national brands are UHP. Trader Joe’s organic is not.
- Yogurt from a previous batch or some plain yogurt from the store with live active cultures. I started with Trader Joe’s Greek-style plain yogurt last summer. (Can you tell there’s a Trader Joe’s up the street?)
- A mason jar or two (with lids), depending on how much yogurt you want.
- A large pot.
- A cooler.
- A thermometer is helpful, but if you don’t have one you can use other means to test the temperature of the milk; the milk hits 180 a few minutes after the water starts boiling if it’s come straight out of the refrigerator, and it is cool enough and ready for the live active cultures at or a little above human body temperature, so when you can stand to touch it.
First, fill a couple of mason jars with milk. Set them in a pot of water. Heat the milk to about 180 degrees (I’ve tried lower temperatures and gotten runny yogurt). My thermometer has an alarm, so I can leave the yogurt unattended until it hits 180.
Once the yogurt is heated, remove the jars from the pot and reserve the hot water in a cooler. This part always makes me feel like Faust.
Let the milk cool to between 90-120 degrees F. For the impatient among us, an ice bath makes this happen quickly.
Remove the jars from the ice bath and add the ice water to the hot water in the cooler. Add a dollop of yogurt from your previous batch to each of your jars of milk, stir, and put the lids on the jars.
The water in the cooler should be somewhere around 90-110 degrees (this happens magically when you mix the hot water and the ice water). Put your sealed jars in the cooler, pop the lid on, and leave for anywhere from 5-8 hours.
You can check on your yogurt after about five hours and if it looks more liquid than you’d like, leave it in for another hour or so. I usually end up leaving mine in for about eight hours, or even overnight when I forget about it.
Once your yogurt is done, you can eat it straight, mix it with fruit or honey, or (my favorite) use it as an accompaniment to food. It’s a great sour cream substitute. I had yogurt with all three meals yesterday: on oatmeal, with borsch for lunch, and with biryani for dinner.
To make labneh (pictures here), or yogurt cheese, you just need to dump one of your jars of yogurt into some cheesecloth and either hang it for a while (overnight is good) and let the whey drip off, or put the cheesecloth into a sieve and let the whey drip off that way. (Save the whey, it can come in handy.) Labneh is delicious on toast, fruit, frittatas, and apparently you can even use it to make cheesecake. I use it in recipes in place of cream cheese or goat cheese.
To make more complicated cheese, I defer to Ricki the Cheese Queen of the New England Cheesemaking Supply Company. I ordered the 30 Minute Mozzarella and Ricotta Kit. I don’t make this kind of cheese often, because just buying mozzarella is cheaper and easier than using a gallon of milk, half an hour, and getting a lot of dishes dirty to make not-very-much mozzarella (and a whole ton of whey). If I ever get my goat farm or backyard cow I expect to become much more interested in cheese-making.
UPDATE: I had my first yogurt-making drama today, March 26th. Well, actually, the drama started when I let my yogurt hang out in the fridge for two weeks instead of the usual week, which I think killed or substantially weakened the live active cultures. Last week’s batch of yogurt tastes fine but is so runny it’s not worth much. So today, I went and bought an extra quart of milk and a starter culture (by which I mean a tub of plain Greek yogurt). I was making two quarts of yogurt, and everything was going fine until the cooling process, when the temperature differential between the ice water and the hot jar of milk caused the glass jar to break. I was aware this could happen, but it never had before. Also, if you’re going to break a glass, doing so in a contained environment (like a big metal cooking pot) is the way to go. (I break a glass about once every week or so.) But, if you’re going to use boiling water and then an ice bath, it is probably a good idea to let the jars cool down in the open air for several minutes in between.