Homemade Yogurt

Once you really think about it yogurt is kind of disgusting. Especially after working in a lab. Essentially you take bacteria from an already started yogurt culture (either store bought or from a previous homemade batch) and give it some food (milk) and let them go crazy, feed, and multiple. The result is delicious yogurt! But all I can think about is how I basically just made a homemade culture of bacteria is a makeshift incubator. Mmm.

To achieve the texture and taste of yogurt bacteria have to ferment lactose (a sugar found in milk) in the milk into a byproduct called lactic acid in order to produce energy for themselves. This byproduct of their metabolism in turn can interact with other milk proteins and actually curdle them (being that lactic acid is, well, an acid) giving yogurt it's delicious texture and taste.

Making homemade yogurt is easy and once you have a batch going you can continually renew it each week.

32 oz. fresh milk (not non-fat - I used 2%)
1/4-1/2 (one small container) of store bought or homemade yogurt
*Note: make sure if you're using store bought that it says "contains live cultures"

Heat the milk to 170 F (to kill anything nasty in it). Make sure it does not pass this point so use a thermometer and monitor it carefully. Once it reaches this temperature remove it from heat and cool it down to ~105-115 F. Mix in your yogurt starter. You must be sure to let the milk cool to this point otherwise you'll kill the bacteria you're carefully adding in. From here you can do a couple of things. One, you could fill a small ice chest with water no hotter than 115 F and place the yogurt in a separate container within the ice chest. Secondly, you could try the oven method of heating it to 175 F, turning it off, and placing the yogurt in a container inside the over. Either way, you want to let the yogurt sit for 4-8 hours depending on the consistency and sourness you like your yogurt at. The long you let it sit the more lactic acid will build up and the sourer your yogurt will be.

This is plain yogurt so you could mix in fresh fruit, sugar, agave nectar, honey, or my favorite: rhubarb strawberry compote.