Thursday, June 2, 2011
Then I discovered Greek yogurt, and I was hooked. If you haven't tried it, Greek yogurt - or more accurately, Greek-style yogurt - is a thicker version of regular yogurt.
There are a few ways to thicken yogurt. You can add things to it - like gelatins and gums - or you can strain it. "Real" Greek-style is strained, which removes some of the whey. Turns out that the astringency of the whey is precisely what I didn't like about yogurt. Straining some of whey out of the yogurt fixes that problem for me.
But before we get to the straining, the yogurt has to be made. It's a very simple process, and you don't need a yogurt-making machine or any special equipment besides a decent thermometer.
You can buy dried yogurt starters to get your yogurt going, but you don't even need that. Commercial yogurt makes a fine starter as long as it has active cultures. Choose a brand that you like. Your yogurt won't be identical in flavor, but it will be similar.
Powdered milk helps increase the amount of yogurt you’ll have after straining, but you don't want to go overboard. Early in my yogurt-making days, I experimented with adding more powdered milk, and the yogurt had an odd flavor that I didn't like. A little bit is fine, or you can leave it out
When I make yogurt, I start with a half-gallon of milk and end up with about a quart of yogurt. It lasts for quite a while - I mean, yogurt is fermented milk - it's not like getting more fermented is going to make the yogurt dangerous to eat. Yogurt can get moldy, but it doesn't happen quickly. If you're squeamish, make just enough to last as long as you're comfortable with.
I don't flavor my yogurt as I’m making it. To me, plain yogurt makes more scnse since I can add flavor or fruit later, or use it for savory recipes. As far as the leftover whey, even though I'm not fond of the whey flavor in yogurt, I think it's a great addition to baked goods. So nothing is wasted.
1/2 gallon milk
1/4 cup dry milk (optional)
1/4 cup commercial yogurt with live cultures (unflavored)
In a large, heavy-bottomed pot, combine the milk and the dry milk, if you're using it. Heat to 160 degrees, then turn off the heat and let it cool to 120 degrees.
Put the commercial yogurt in a small bowl. Add some of the warmed milk, and whisk to combine. Add the warmed yogurt back to the milk, and whisk to combine.
Now comes the (slightly) difficult part. The mixture needs to be kept warm while the cultures grow and the milk turns into yogurt. You can do this by covering the cooking container and putting it in your oven with the light on, or by wrapping it in a few layers of towels and putting it into a cooler.
Another important thing is to keep the yogurt undisturbed while it ferments. If you jiggle it or stir it, it might not set properly and you'll end up with a pourable yogurt instead of a spoonable one.
The mixture is as firm as it will ever be after about 4 hours. You can leave it longer - up to 8-10 hours total. the difference is that the longer you leave it, the more tart it will be. I usually let mine go for about 6 hours, but I've left it much longer, as well.
Put the yogurt in the refrigerator to chill completely. This stops the fermenting process.
When the yogurt is completely chilled, strain it. I use a very fine-mesh metal strainer, but if all you have is a coarse strainer, line it with a couple layers of cheesecloth. Don't stir the yogurt before straining, just put the strainer on top of a suitable container to catch the whey as it drains, scoop the yogurt into the strainer, cover it plastic wrap, and put the whole thing in the refrigerator and forget about it for a few hours.
I use a large glass measuring cup to catch the whey. For one thing, it's the perfect size for my strainer. For another, it lets me see how much whey had drained out. The longer you strain, the thicker the yogurt will be - it will take several hours, at least, depending on how thick you like your yogurt. I usually strain until I have half the original volume.
Transfer the strained yogurt to a container for storage. Whisk it to smooth it out, then refrigerate.