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Use, Care and Maintenance of Pyrex Ware

Cooking In Pyrex

Besides its versatility as an all-in-one cooking, serving, and storing utensil, one of the advertised primary benefits of cooking in glass was its energy savings over metal cookware. Since the glass absorbs and conducts heat energy rather than reflecting it as metal can, it meant cooking temperatures could be lowered, saving fuel while still achieving the same results.

To avoid stuck on foods, early literature advised greasing the oven ware before cooking "food mixtures" as well as before baking.

Other than Pyrex Flameware, clear (post-1950) and opal glass Pyrex bakeware use is restricted to conventional oven and microwave only. Clear Pyrex from the 1940s and earlier should not be used in a microwave.

Remember that Pyrex decorated in gold leaf or other metallic paint is incompatible with microwave ovens.


If you want to clean up a Pyrex piece you've found and added to your collection, or need to clean one you use, it is imperative that you exercise caution and care in order not to damage either the piece or its finish.

During use, never subject hot Pyrex to cold or much cooler temperatures, such as by pouring water in a hot bowl or pan. Always allow an oven hot piece to cool on its own to room temperature before immersing in even hot dishwater. As heat resistant as Pyrex is, it is vulnerable to thermal shock when a portion of the piece cools more rapidly than the rest. It is for the same reason Pyrex ovenware should not be used over a stovetop burner or under a broiler. Literature included with Pyrex even warned against handling with or placing on a wet cloth. Be aware that the result of thermal shock can be sudden, explosive, and potentially injurious. Refrigerator stored pieces, however, may be placed directly in an oven because the entire piece will be exposed simultaneously to the same heat and its temperature will change evenly.

For recently baked on residue, soaking the piece in hot tap water is often sufficient. Household products advertised to accelerate this task are normally fine on bare glass Pyrex interiors. Harsh products may be a risk, however, on patterns and color finishes. Resist the urge to scrape your Pyrex with metal utensils, and never on colored or decorated areas. Decoratively patterned areas are best avoided, and gold leaf decoration should definitely be avoided with any abrasive or chemical.

For tougher baked on residue, again on unpainted or undecorated surfaces, mild abrasives like Bar Keeper's Friend or Mr. Clean Magic Eraser pads may be effective. Both may also be used with discretion on colored but undecorated surfaces, but at the user's own risk. BKF applied with a wet paper towel and a light touch is often all that's required to remove typical oven rack marks.

For removing some tougher metal transfer marks, a product called Nevr-Dull has been shown to be effective. Actually a petroleum distillate-based metal polish, it appears to remove such marks with little effort and no apparent damage to base color finishes. It is supplied as a cotton wadding impregnated with the cleaning agent. It is also helpful in removing adhesive residue left by some types of clear packing tape sellers often use to secure lids to dishes.

Also effective on metal marks is Peek metal polish, supplied in paste form.

Users of either Nevr-Dull or Peek may want to approach decorative patterns, particularly gold leaf, with care or avoid them altogether with these products. Both products can also be considered for freshening up tarnished metal cradles, with varying results.

With any cleaning products, pieces should be washed with a liquid dish soap, preferably Dawn, and water to remove residue before further usage.

Grooves and crevices common on Pyrex ware present a bit of a challenge, as residue within them tends to defy scouring or scrubbing. A common wooden toothpick is often just the ticket, as are bamboo skewers. Again, no metal on Pyrex.

General Care

Once clean, there isn't much to maintaining Pyrex beyond careful handling and storage. Although tough, Pyrex can still chip, especially at points like the protruding handle edges on some bowls and covers. The undersides of handles are also susceptible to rub wear and paint loss.

Since the lids do not fit tightly and the contact points between them and their dishes can be slippery ones, handle your dishes carefully, securely, and with both hands when the covers are on. A better idea is to just carry dishes and lids separately.

Although Pyrex is heat resistant and reasonably durable, it is not unbreakable. When it does break, it often does so into many shards, jagged and razor sharp.

With a few exceptions, Pyrex lids are designed to double as trivets for the dishes they fit. The base of a dish will sit comfortably in the inverted flat-topped, tab-handled cover. Inverted lids placed on top of their dishes also allow stacking of similarly shaped pieces in a more secure manner and with less chance of damage to painted lid decorations.

Nesting bowls can be protected by placing paper coffee filters or even just paper towel between them. Lids can be kept from clanking against their dishes by improvised small pieces of foam rubber or other soft but resilient material placed between them at several points.


Like any enthusiast, the Pyrex collector, in addition to cooking, enjoys being able to have at least some nicer pieces on display. This can sometimes be a bit tricky, as even a small collection of Pyrex can take up some space. Some possibilities include:

· Open Cabinet
· Baker's Rack
· A vintage Cosco metal kitchen cart
· Storage Cubes
· Wire Shelving aka "Metro®" Rack

Any method of display chosen must take safety into consideration. Shelving and racks should be sturdy enough to support the weight, and secured to a wall to prevent collapse if climbed upon by curious children. Falling glassware risks not only damage to the piece itself, but also injury to whomever might be struck by it.

Be careful of any shelving unit with exposed sharp metal that might scratch or mar your Pyrex.

Don't be tempted to show off your nesting bowls by stacking them upside down in a tower, as often shown in online auction photos. This risks damage to the paint where the adjacent bowl's rim rubs the outside of the next. Similarly, don't nest bowls of the same size directly together or larger bowls inside smaller diameter ones, for the same reason.

When storing or displaying your refrigerator set pieces, note that the lids invert and offer a more stable stacking solution.

Spacers made from a variety of materials or objects can be used to give smaller nesting bowls a partial "lift" above the rim of the bowl below in order to show off color or pattern. Ziploc brand #10875 14 oz. round storage containers were formerly a very popular choice for this purpose, but have apparently been discontinued. Other good choices include generic plastic 8 oz. deli containers of approximately 4.5" top diameter and 1.5" height available from a variety of online sources. Lids may be used as insulators between nesting bowls for storage.

A popular practice among collectors with larger, more varied collections is to occasionally, regularly, or seasonally change out displays according to themes or holidays.

However you choose to do it, having all or part of your collection nicely on display can be an attractive part of home decor.

Long-Term Storage

You may get to a point where you need protected storage of parts of your collection. Or you may need to box some of it up to move. Chances are slim that you have original boxes and packing material. New cardboard cartons can be had relatively inexpensively, and being able to choose exact dimensions acoording to your needs is a plus. For example, the Office Depot SKU#246748, at 11" x 11" x 5", is a perfect size to hold either a 400 Round or 440 Cinderella bowl set. Cushion the bottoms with slightly crumpled paper, and place layers of paper or bubble wrap between bowls.

While well-suited for this application, be advised these cartons are too small to adequately protect sets or even individual bowls in parcel shipment.