Okay, this is one of those ongoing arguments: some say “yes” and some say “no.” But first, why is cream of tartar even an issue?
Cream of tartar, also known as potassium hydrogen tartrate or potassium bitartrate (KC4H5O6), is a white, powdery, acidic substance that is a byproduct of the wine-making industry. It is found on the inside of wine barrels after the grapes have fermented. The tartrate is processed into a salt which has many culinary uses.
Candy makers add cream of tartar to sugar syrups to prevent crystallization. Without the addition, candy made from sugar syrup has a grainy texture. With the addition, candy has a smooth, glossy, and creamy texture.
When beekeepers started using candy recipes for making bee supplements, many left the cream of tartar in the recipe. It was left there without much thought about its purpose. So basically cream of tartar in “bee candy” is just an artifact remaining from “people candy” recipes.
Although the debate continues over whether it harms bees, I’ve never seen data from even one controlled scientific experiment concerning this issue. So, in short, I’m just as clueless as anybody else about the chemical’s effect on honey bees.
However, since we don’t know if it causes harm, and since it doesn’t appear to be a part of the honey bee’s natural diet, why give it to them? So the sugar cakes are gritty–so what? I’ve never heard a bee complain about gritty-textured candy and I’ve never seen a bee push away from the table when presented with it.
So stop being so anthropocentric! Just skip the cream of tartar and make bee candy with sugar, water, and one of the essential oils known to be good for honey bee health such as spearmint or lemongrass. That’s it—there is really no need for corn syrup, cream of tartar, vinegar, preservatives, stabilizers, emulsifiers, or anything else humans may like in their sweets.