Last week, we created yogurt. We scalded milk, waited for it to cool, added yogurt, and waited for a night. It was successful. We also tried to make yogurt without using lactose, and it did not go well. We took the same exact path as the successful yogurt, except instead of using milk we used coffee creamer. The reason that the second batch didn’t work was because the bacteria needed for yogurt had no lactose to eat. For yogurt to become yogurt, a bacteria called lactobacillus needs to eat lactose and excrete it. But when the bacteria has nothing to eat, it dies. That’s why instead of turning into yogurt, it just stayed as creamer. Some people say that there can be lactose free yogurt, but it isn’t possible.
We learned a lot of cool new stuff. We learned that yogurt can’t become yogurt without lactose. We learned that without bacteria, we wouldn’t have a lot of things. We wouldn’t have yogurt, pickles, a few types of sausages, bread, humans, plants, most of the earth, etc. Making yogurt, a few things surprised me. One of them was how many things we wouldn’t have without bacteria. Anther thing was how much bad ingredients are added to creamer. Last week, one thing that I would have done differently is trying less of the creamer. I drank a few sips to see if it resembled yogurt at all, and it didn’t. All it did was make me feel gross. Why did we have to scald the milk before adding the yogurt? Where does that sour flavor in yogurt come from? When the yogurt is ready, is the bacteria still eating and excreting lactose?
This is such a great post-Savannah! I can tell you really understood the scientific process we went through to prove bacteria need lactose to make yogurt. I loved how you described the process as the “path”. I might use that when I teach as it makes sense. We scalded the milk to make sure there weren’t any bad bacteria in the milk. The sour flavor comes from the acid by-product the bacteria produce. And yes the bacteria is eating the lactose until it is done.