Lately I have been growing crystals to view under polarized light. I found that Ascorbic Acid can grow some interesting crystals. Since my Beerenol recipe uses Ascorbic Acid I decided to see if it would grow crystals. It grows some interesting crystals that are small and look kind of like snowflakes. They are not thick enough to get a lot of color. The shot below was taken on black and white film and, of course, developed in Beerenol. The microscope is a Leitz SM, this shot was 100X magnification.
Beerenol Crystals by Bryan Chernick, on FlickrIf you want to try growing some yourself here is the recipe, it's scaled to develop a 35mm roll of film, a lot more than you would need for a few slides, I wouldn't recommend drinking the leftover.:
Beer (I use cheap Lager, like Pabst Blue Ribbon but any beer will work) - 12oz
Sodium Carbonate (Arm & Hammer Washing Soda) - 2.75 Tsp
Ascorbic Acid Powder (Vitamin C) - 1.25 Tsp
Salt (Morton's Iodized Table Salt) - 1/4 Tsp
Add the ingredients in the order listed above, the Sodium Carbonate will take about 5 minutes to fully dissolve in the beer, then add the other ingredients. The Sodium Carbonate will make the beer flat, if you add Ascorbic Acid to the beer before it's flat you will get a foam explosion.
If you are interested in how it does developing film I create a Beerol Flickr group. It has discussions about recipes and photos developed in Beerenol.
https://www.flickr.com/groups/3705975@N20/