I'm planning to do a biology experiment where I look at some yogurts with natural sugar and some with sweeteners to see whether the spoilage rates are roughly the same by studying the lactic acid production.
I plan to investigate this by counting the number of lactic acid bacteria colonies.
I've looked at a few methods and had a few questions. Why do some state that the experimenter should not "pour plates in direct sun light" ?
I've noticed that often, inconsistent sized colonies including pin point colonies form on the agar, I was wondering how I could reduce these to a minimum?
All advice is very much welcome!