How to clean Vintage Pyrex
First, a general disclaimer:
You attempt any all of the following suggested methods for cleaning Pyrex at your own risk. We haven’t tested all of these methods, and everyone’s situation and Pyrex objects are different.
Here are some of the DON’Ts for cleaning Pyrex:
1. Don’t ever put colored vintage Pyrex in the dishwasher. The delicate colored designs can be affected by both standard dishwashing detergent as well as high heat. I think the colored patterns are actually a secondary step of the glassmaking process where it is actually “sprayed” on and then fired. This may not apply to older standard Flameware and Ovenware or newer Pyrex pieces.
2. Don’t heat up your Pyrex and then try to clean it. I’ve seen several online sources say that this may be a good way to clean it in combination with either baking soda or oven spray. This can be disastrous to your collectible and extremely dangerous to your person as heating Pyrex up on the stove can somtimes cause it to shatter. Others swear by this method, but I wouldn’t chance it.
3. Don’t put any chemicals or abrasives directly on the colored patterns on Pyrex. While the insides of bowls and casseroles may be able to take stronger chemicals and cleaners like Comet, Bon Ami, Corning Cleaner, general oven cleaner or even vinegar, cleaning the colored patterns too many times with these methods may eventually cause damage to them. You may not notice it the first time, but eventually there will be degradation.
Methods for cleaning Pyrex
The safest way to clean an entire Pyrex piece is with soapy water made with a gentle dishwashing liquid and a non abrasive sponge. Rinse thoroughly with clean water and then dry with a soft dishtowel.
• For old sticky price tag residue: Various readers have commented on this. Methods include soaking in hot water and using a fingernail to scrape it off (from Jenny), covering in baby oil for a few hours and using thin hard plastic, like an old credit card, to scrape it off, or applying scotch or packing tape repeatedly to get sticky residue off (from Robin).
• For tough bits of dirt and food in fine crevices: You might not even care, except that sometimes if an item is lighter colored, the dirt can really show up. In that case, you may want to try out our “toothpick” method described here, along with the normal soapy water routine.
• For stains and silverware marks on the INSIDE of items: We now recommend Bar Keepers Friend for non-colored/patterned areas of Pyrex. For examples, see our article on BKF.
Depending on the state of the finish on the inside of your item, you might be able to use any or all of the chemicals and cleaners listed above. Abrasives like Comet, Ajax and steel wool are probably a last resort, i.e. if the inside is already severely scratched. Some people swear by a baking soda solution to get the inside clean. Others use Magic Eraser sponges, Toothpaste, Bleach cleaners (we would avoid this) or vinegar solutions. Because it’s the inside of the bowl many people don’t seem to care about introducting extra scratches or wear. However, remember that deep scratches can catch more baked on food and lead back to the cycle of trying to clean off yet more food and more scratches.
• For stains on the OUTSIDE of items:
We now favor the use of Magic Eraser on colored portions of Pyrex Items where you MUST use something stronger than soap and water. This tends to get a lot of yellowing and baked on grime off. USE CAUTION and be gentle with the eraser… it WILL take off some of the finish if you use it too much.
The colored finish of some vintage Pyrex items are susceptible to scrubbing w/ Magic Eraser. In particular, if an item has a “matte” surface instead of “shiny” surface (for instance, Terra patterns and also portions of the tops of some Promo Casseroles like the Sol Flower) you should be very careful. We have had some of the finish come off when trying that method.
All bets are off when using any harsh chemicals or abrasives on the colored pattern part of vintage Pyrex. This should only be done as a last resort, or if you don’t care about the collectible nature of the piece you are cleaning. In all cases, it’s best to first test a tiny (hopefully inconspicuous) spot with whatever you are using to clean your item. Be careful of any method which tells you to completely immerse a piece of Pyrex in any solution other than standard soapy water because you can’t control the effect of the solution on the colored patterns.