1 Mar 2010

Bacterial confection

March 1, 2010 506, assignments Comments Off

Put down the Purell. Step away from the Dial.

Bacteria is not the enemy.

I’m going to show you how to use bacteria to our advantage, and turn plain old milk into delicious yogurt, full of bacteria that will help, not hurt.


You don’t need a lot, just a quart of milk, a little bit of yogurt, a double boiler, a candy thermometer, and either a yogurt maker or a crock pot or even a heating pad. Oh, and a jar to put the yogurt in.

getting ready

First, sterilize everything. Boil your spoon, the container and your tools in the pan for five minutes. You can skip this step, but since this is all about growing bacteria, you should make sure you kill the bad ones, first. Place your tools on a clean towel, and now you’re ready to start!

starting outSlowly heat the milk in the double boiler — if you don’t have a double boiler, use a heavy-bottomed saucepan — with the candy thermometer clipped to the side of the pan. Don’t let it touch the bottom of the pan, because then it won’t give you an accurate temperature.

Stir frequently, because you don’t want the milk solids to stick to the bottom of the pan!

heating up

Once the yogurt gets to 185 degrees (or thereabouts), take it off the burner and let it cool down to 110 degrees.

cooling offYou can speed this up by placing the pan in a bath of ice water.

Once the milk is cool, stir a spoonful of the yogurt you’re using as a starter. It doesn’t matter what kind you use — in fact, the fancier organic Greek-style types aren’t the best, you want just plain old yogurt.


You can even use a flavored kind if you’ve already got that, because you probably won’t be able to taste it in the finished product. If you want to make vanilla yogurt, add a teaspoon of vanilla to the mix.

Next, pour the mixture into the glass or ceramic container — plastic or metal doesn’t work well — and let it rest.

pour it inTo keep it at a constant temperature of 100-110 degrees, you can put it in a yogurt maker, on a hot plate, in a hot water bath in a slow cooker, in the oven with a pilot light on or wrap the jar in towels and a hot pad. Just make sure it doesn’t go much below 100 degrees or up near 120 degrees. You want to encourage the bacteria to grow, not kill them!

on the plate

In about six to eight hours, check on the yogurt. Tip the jar to see if there is solid yogurt with clear or yellowish-green whey inside — if there is, it’s done! Though you can leave it a bit longer to make it more tart.

If it’s not ready yet, leave it for a bit longer — sometimes it can take as long as 10 to 12 hours before you can stick it in the fridge. The bacteria need time and heat to multiply.

stick it in the fridge

That’s it! You’re done! You can play around and try adding different extracts to flavor it, or different kinds of milk. Any kind will work, but skim milk benefits from about a third of a cup of dried powdered milk. But really, that’s all it is.

all done!

Next up, how to make your own granola at home to go on top of that delicious, good-bacteria-filled yogurt!


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