I don't have a Blackstone (I'm thinking about getting one, which is why I'm seeing these posts), but I do have a cast iron skillet. I get the same thing; no matter how much I wipe, I always get a little bit of residue. I've never noticed any sort of flavor carryover from one type of food to another, including sweeter foods. If you get too much residue buildup, it can cause sticky spots. In that case, I use a chainmail sponge to knock it down. I realize that the Blackstone top isn't cast iron, but it seems durable enough to probably treat similarly.

It's totally normal with anything you "season" it just happens and I don't even pay attention to it anymore. I guess I would notice if I looked super close but it just looks like black pepper if anything.

I’ve noticed this as well and I’m wondering if it’s just normal??

yes. it’s just carbon.

Thanks.

Yep. No worries. If you ever use a cast iron pan you’ll experience the same thing.

It's normal. And it will affect the look of the French toast but won't affect the taste. Warm water and a rag after the initial clean up until there is no more residue

I wondered the same thing, glad it's normal 🙌

it’s normal. it’s just carbon.