ACEIZE Tracking the current state of Science and Technology

This article was originally published on July 20, 2005 at smokincat.com -- the first of many websites that I have put together. I shut the site down today and moved some of the old articles over here.

In order to settle a dispute I undertook a bit of scientific investigation. I was hoping to determine if whole milk or skim milk went sour faster. So I bought skim milk and whole milk. Both jugs had the same expiration date. I left them in my fridge over night to make sure that they were both at the same temperature when the experiment started.

I then poured milk in equal quantities into two glasses. The glasses were left in my un-airconditioned kitchen, which ranges in temperature between about 84° F to 96° F (from what I saw over the last two days). I tried to take a look at the glasses every hour and take notes on the appearance, smell and taste of each glass.

I have run through the experiment twice. The first time I started early in the morning. Both glasses were fine when I went to sleep around 12. By morning, around 7, they were both the consistency of yogurt. The second experiment was this afternoon. I put the glasses out last night around 12. When I woke up both glasses were fine. I continued to check them every hour until about 3:30, when I fell into a poorly timed afternoon nap. When I woke up around 6:30, both glasses had once again achieved yogurt status.

My conclusion is that the experiment was not definitive. Although the time difference between souring must be shorter than 3 hours. I am nearly ready to declare that the difference is insignificant, and that skim and whole milk sour at similar rates. One thing that I noticed was that whole milk looks like it is having consistency problems much earlier. ie. There is visual evidence that the whole milk is beginning to sour - although the same signs can be seen in skim milk to a less obvious extent.

I'm going to try the experiment once more. I want to know within one hour which type of milk, if any, sours first.

http://www.ars.usda.gov/is/kids/mailbag/spoiledmilk2/badmilk2answer.htm