Hmmm darn it! Makes me nervous because I do cut out sugar cookies, so I'm constantly putting flour in my baking surface and didn't notice anything
Don't feel bad, it's very hard to detect flour bug infestation Anyone who bakes a lot is going to encounter a flour beetle or flour mite infestation. It's part of baking. When you purchase new bags of flour trying not to shake them around much. When you open them, look inside the bag before you do anything. If there are small holes in the flour, as if someone took a small tiny stick and poke holes , return the flour to the store. Those holes are an indication that there are bugs in the flour.
Mills inspect for infestation on regular schedules. But infestations still happen. So it's always a good idea to check the flour in the bag as soon as you open it.
More often than not bakers don't notice infestation in their flour. The eggs are microscopic so you can't see them. And frequently the adult bug appears as a tiny speck, so go unnoticed, especially if they're using a high extraction flour as it's very coarse.
Looking at your sugar cookie ingredients list, there's nothing in there that would crystallize to a hard black granule. If you were using vanilla paste as opposed to extract you would see tiny black flecks of vanilla bean, but they're not like granules. They're just tiny little flecks of which you cannot feel the texture. I routinely use vanilla paste and it certainly is not anything you can feel, let alone separate from the dough.
Infestation doesn't necessarily even have to originate from your flour. Any grain, cereal, rice, stored in your pantry could be the source. It's always best to store all these types of foods in air tight hard plastic, glass, or metal containers. Try to cycle through these products within three months. The longer these products are stored in your pantry that greater likelihood of infestation
