May 21, 2011 § 4 Comments
During my first visit to China, one of the most memorable things I consumed was the yogurt. The yogurt there is so drastically different from what Americans eat that it’s hard for me to even compare them in my head. Chinese yogurt has a much thinner consistency, much more similar to buttermilk’s viscosity, is tangy and sweet, and is served in a glass bottle and sipped, rather than eaten, through a straw.
Since that trip, more than five years ago, homemade yogurt is something that has been frequently made during summers in my house. This yogurt makes a delicious and refreshing beverage on any hot summer day and can be sweetened with honey, sugar, or any other sweetener of your choice. As with many of my family’s recipes, there are no standard measurements for, but rather made-up units such as ‘a bowlful’ and ‘two scoops’.
The important thing to know about yogurt is that temperature is the most important factor that controls how fast your yogurt will form, if at all. The two biggest reasons that we make yogurt exclusively during the summer are because, first, no one’s ever in the mood for it in the dead of winter, and secondly, it’s far too cold for the bacteria that make yogurt yogurt to reproduce and thicken up milk.
Since I have always been a science dork, I took some time to understand the biology behind yogurt. There are two bacteria that are responsible for the viscosity and tang that are attributed to yogurt. Lactobacillus bulgaricus and Streptococcus thermophilus use the sugar in milk (lactose) to transform milk proteins into a polymer that creates a gel matrix in the milk. While that’s all good and interesting (to me) what you need to know is that you have to repasteurize your milk to kill any bacteria that might have developed, then let it cool, add the commercial yogurt culture, and let it incubate.
a very vague family recipe
1 bowlful skim milk
2 spoonfuls of yogurt with LAC (live active cultures)
Place the bowlful of milk into the microwave and heat until just before boiling and is too hot to touch. This will pasteurize the milk and kill the bacteria that might be growing in it. Let it sit and cool on the counter for a while until it’s cooled down enough to place a finger in it comfortably.
Whisk in the yogurt with LAC until smooth and cover the bowl with a piece of plastic wrap. Let it sit on the counter for at least a day. Depending on your house’s temperature, it may take more than a day. Give the bowl of yogurt a good stir everyday until it’s thickened up to the proper consistency.
If there is too much whey (liquid) on top of the yogurt, you may want to strain it, like I did. To do this, just put a piece of cheesecloth over a wire strainer and set that over a larger bowl. Pour the yogurt onto the cheesecloth and let all the whey drain out and then dump the yogurt into a container and enjoy!