This was another science experiment in our chapter on digestion. To show how enzymes help digest our food, we put slices of ham into jars with water and added the enzyme papain (a.k.a. meat tenderizer) to one jar.

After two days, we compared the ham in the jar of just water (top) with the ham in the jar with papain (bottom). 

The jars sat on my kitchen counter for a few days and I didn't smell anything amiss. (I never thought I'd agree to have science experiments on my kitchen counters, but like many other things I said "never" about in the past, I am doing it all the time now.) However, when we opened the lids to discard the ham, it smelled really, really bad.  Just be warned.