Friday, May 25, 2007

The Yogurt Experiment

One of the sticking points for me in trying to eat more locally-produced food has been the dairy category. I go through lots of yogurt and cheese, plus the occasional package of cream cheese or sour cream. There are several sources for locally-made cheese, such as cheddar and jack cheeses from Marshall Farms, fancy sheep's milk cheeses from Everona Dairy, free chevre and "andaluz" goat cheese from Satyrfield Farm, and gouda-style cheese from Our Lady of the Angels Monastery. But the other categories are not as well represented. I used to be able to get yogurt from the Shenville creamery, but Shenville has since gone out of business (which is too bad not only because we lost a source of local dairy products, but also because that yogurt was really tasty).

Recently I was reading on the web about how to make your own yogurt. It sounded pretty foolproof, actually: mix a spoonful of yogurt from the store into a jar full of milk, set it in a warm place for several hours, and that's it. You've made yogurt. The exact quantities and temperature range are not, apparently, all that important. So, I decided try buying some locally-produced milk and converting it into yogurt myself.

I bought a tub of this commercially-produced yogurt and a half gallon of Shenandoah Pride milk from C'ville Market.

I scalded the milk (though I'm not sure now where I got the idea that this should be the first step), poured it into a clean jar, and mixed in a generous spoonful of the starter yogurt.

The remainder of the starter yogurt got combined with some of the strawberry rhubarb glop to make a rich, sweet treat. In the picture below, you can see the yogurt-and-fruit dessert on the left, and the yogurtmaking experiment on the right. The jar is wrapped in a dish towel to help it hold heat for a while.

The heat from scalding the milk would not go on indefinitely, so I needed a heat source to keep the wee beasties in the yogurt-milk mixture happy and active. The first obvious choice was the interior of my car while it was parked in the sun. After the sun went down, I brought the yogurt jar inside and placed it in a pan of hot water from the tap. Before going to bed, I set the pan on the rear burner of my stove, which is over the vent from the oven. I turned the oven on to its lowest temperature and left it on for the night.

The next day: hurrah, yogurt!

The yogurt that resulted from this experiment was very watery. That was OK, because I had been planning to strain it anyway, since I like Greek-style strained yogurt. Here is the first phase of the straining:

When I had drained off most of the liquid and transferred the thicker yogurt to a jar, I assessed the yield from this experiment in yogurtmaking. I started with a pint and a half of milk, and ended up with just under a pint of whey and around half a pint of thick yogurt.

This was a little bit disappointing; I had hoped for a higher yield. But I am thrilled with the yogurt that I made. I haven't eaten it all up yet, but I tried a taste, and it was delicious.

On the next go-round, I might try adding powdered dry milk to the locally-produced milk in order to lower the moisture content. Or I might try stirring some of the whey back into the thicker yogurt in order to make a greater volume of finished product. Or I might just go forward knowing that if I want more yogurt at the end of the process, I need to start with more milk at the beginning!

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