No matter how hard you scrub, there are some stains that just won't come out with soap and water. Case in point: the eternally-dirty sheet pan that always seems to have brown, burnt-on residue coating the sides.
But we don't have to resign ourselves to this fate — there's a simple two-ingredient solution that is probably already in your cupboard.
Mix ½ cup baking soda and ½ cup white vinegar with hot water in the sink. (We prefer Heinz white vinegar and Arm & Hammer baking soda, but this will work with any brands, really.) It will bubble up like a school science project, but that reaction is what helps loosen the residue. Make sure your sink is plugged so your pans stay submerged, and let it soak for 30 minutes to an hour before scrubbing away with a scouring pad, steel wool, or the scrubby side of your sponge. Although steel wool is most likely to scratch your pans, it's OK — you want them to look well-worn and used, but scrub in even circular motions to make the lines less noticeable. That elbow grease your parents always like to go on and on about? Yeah, time to use it.
After the scrub-down, wash with regular soap and water to finishing cleaning, and then dry immediately to prevent rust. This process is also a twofer: It helps clean out your drain — which you definitely don't clean enough — with the combo of baking soda and vinegar. It's all very easy, but remember to rock dishwashing gloves during this process to save your hands from getting all scratched up by the rough scrubber.
I had a sheet pan that I tried cleaning vigorously with my tried-and-true Scrub Daddy sponge at least half a dozen times, but the corners still had mysterious residue lingering around. So I made a soft of bath bomb for my pan, let it soak overnight — because I fell asleep and forgot about it, honestly; an hour probably would have probably been fine — and went to town on it with steel wool. I was hoping for an arm workout, but it was surprisingly easy. The brown stuff came off in a few seconds per scrub, and it wasn't noticeably scratched because most my cleaning was in the corners. I believe in miracles.
Vinegar isn't only for cleaning sheet pans. If there's a similar coating around the edge of a stainless steel sauté pan, boil a few cups of water with ½ cup vinegar for a few minutes, pour out, and wash as usual. We all know not to use steel wool on a Dutch Oven, so this is also a great way to clean it without scratching the precious enameled surface. If this doesn't work, Bar Keepers Friend powder is a good bet. It's powerful, yet gentle on your precious Le Creuset. You can sprinkle some powder directly on a scouring pad or sponge, wet it, and wash in circles.
Once you get 'em clean and looking (almost) as good as new, you'll want to maintain that shiny surface. To help prevent that gunky brown residue from building up again, use parchment paper or aluminum foil to cover your sheet pan whenever you're going to use it — food can't stain that sheet pan if it never touches it.