I’ve been in a whirlwind of making lately, not that you’d know from my (lack of) blog entries! I also went ice climbing recently with friends, which was a blast!
Here is a classic recipe for yogurt that all yogurt lovers should know. It’s very easy and will save you money and keep some plastic out of circulation if you eat lots of this good stuff like I do, especially if you eat organic yogurt.
All you need for making yogurt is a stainless steel cooking pot, a thermometer, starter yogurt (culture), and an insulated container like a cooler, oven, or commercial yogurt incubator. So let’s get to it!
Start with your preferred type of milk in a quantity that you’ll be able to eat within 2 to 3 weeks. I make half a gallon at a time. Heat the milk in a stainless steel pot on the stove, keeping it covered to speed up the heating process. I set a timer for about 8 minutes to help me remember I’m heating milk on the stove. I’ve been distracted too many times while making yogurt without a timer, and the frustration of sopping up burned milk is entirely avoidable.
The heating step is key. The milk must be heated to at least 180 °F (82° C). This is not to kill stray microbes – pasteurized milk is essentially dead, microbially speaking. The purpose of the heating is to denature some of the proteins in the milk. Changes in the protein structure cause molecules in the yogurt to cohere better, resulting in creamy yogurt. If you don’t heat the milk, the consistency will be unreliable (er, inconsistent!). My yogurt used to turn out runny at least half the time until my friend Mamta told me that Indians, who know how to make yogurt, always boil the milk.
Once the milk reaches 180–200 °F, I turn the heat down to the lowest setting and let it stay at that temperature for 10 to 15 minutes. I do this to keep the denaturation process going, and it results in incredibly thick, creamy yogurt. After the heating is done, set it on a rack and let it cool to 104–113 °F (40–45 °C). This temperature is also important – it’s the ideal range for the lactobacilli, streptococci and bulgaricus bacteria (the probiotics!) that ferment the lactose. If it’s not in this range, you will probably not end up with good yogurt. Then add a spoonful of starter culture (PLAIN yogurt at room temperature) to your incubating container, pour in the cooled milk, and stir.
Put a lid on the container with the milk and starter culture, and put it in the incubator. This can be a small cooler with warm water (104–111 °F) in the bottom, or you can put the container in the oven with the pilot light on, or turn the oven on briefly just to warm it up.
Leave the yogurt to ferment for 6 to 12 hours. I usually leave it for at least 10 hours to maximize fermentation. Do not move the container while it’s fermenting as this could disrupt the process.
After the fermentation, chill it in the fridge and stir it with a whisk before dishing it up to keep the whey from separating. Then enjoy your delicious, healthy homemade treat!
A money (and plastic)-saving tip: You can freeze portions of yogurt (your own or store-bought) to use later as starter. Freezing won’t hurt the bacteria and will keep the starter fresh until you’re ready to make your next batch. Just thaw it out to room temperature before you use it. Every time I make a new batch, I freeze a fresh portion in the little containers shown here.