|MadSci Network: Microbiology|
> ... on the cheddar first there was white fuzz, then there were green > spots which eventually turned black. could you please explain these > stages to us. Sure! First, keep in mind that even if you don't see anything going on, the molds may be growing. They are microscopic, so you won't see them until there are so many cells that they become *macro*scopic. The "white fuzz" is made of mold hyphae. They are sort of like the "roots" of the mold. The green color is from the mold spores. Spores are like the seeds of the mold. Have you tried looking at any of these samples under the microscope? Molds can be very interesting and even beautiful under the scope. I'm not sure what the black color is from. Molds don't usually change color with age, so the black color is either from a different species, or is just a really dark green color. Taking a look at both samples under the microscope miqht shed some light. > Also the other two cheeses(romano and parmesan) did not get moldy but > they sweat a lot. These two cheeses have a lower "water activity". Water activity is not the same as water content, but is a measure of the available water in a food. Because these cheeses have less available water, molds grow slowly or not at all. Also, because of the low water activity, these cheeses tend to absorb water from the air... this is the sweating that you see. Eventually, the water from the sweating may raise the water activity to the point where mold growth is possible. Good luck with your experiments.
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