Bakeware care and cleaning

Four materials, four sets of rules

Bakeware care advice is usually written as though there were one kind of pan. There are four, and the rules genuinely conflict: what is right for glass will ruin a coated loaf pan, and what is right for bare aluminum would be pointless on glass.

Why bare aluminum goes dark, and why that is fine

Aluminum oxidizes. Baking fats and sugars polymerize onto the surface, dishwasher detergent strips the oxide layer unevenly, and hard water leaves mineral deposits. The result is a pan that within a few months looks nothing like the one you bought.

None of that affects how it bakes in any way that matters, and a darker pan browns very slightly faster - which is why a well-used sheet pan is often the one people reach for. Nordic Ware warrants its Naturals line for life and advises against the dishwasher; both of those facts are consistent with a pan meant to look used.

If you genuinely want a sheet pan that stays looking new, buy a coated aluminized-steel pan and accept the coating as a wear item. That is the real trade, and it is laid out in sheet pan materials.

Warping, and the sound every baker knows

The bang from the oven when a sheet pan buckles is thermal stress. The pan heats unevenly - one area expands faster than the rest - and the metal releases the strain all at once.

1. Thin pans warp; thick pans do not. Gauge is the single biggest factor and almost nobody publishes it, Nordic Ware included.
2. An encapsulated steel rim resists it. That rolled steel edge on a good half sheet is a stiffener, not a decoration, and it is why the Nordic Ware pan does not buckle.
3. Never run cold water onto a hot pan. This is the most reliable way to warp aluminum permanently.
4. Do not put a cold pan under a broiler. Extreme radiant heat on one side is the worst case.
5. A warped pan can sometimes be flattened on a hard flat surface with a mallet and a cloth, but it never comes back fully.

Shifting baked-on grease without wrecking the pan

The brown polymerized film on an old sheet pan is oil that has cooked into a varnish. It is harmless and mostly not worth fighting. If you want it off, the order of escalation matters.

• Hot water and a long soak. Free, and it removes more than people expect.
• Baking soda paste. Mildly abrasive, safe on aluminum, safe on most coatings if you use a cloth rather than a scourer.
• Baking soda plus a little hydrogen peroxide. Left for a couple of hours, this lifts polymerized grease well. Safe on bare metal, and worth testing on a coated pan first.
• Barkeeper-type powdered cleaner. Effective on bare metal and glass. It will dull anodized aluminum and it will damage a coating.
• Oven cleaner. Caustic. Never on aluminum - it attacks the metal itself, not just the deposit.

The stainless equivalent of this problem is covered in cleaning burnt stainless, where the chemistry is different because the metal is.

Coated pans: the rules that keep them alive

A silicone or PTFE coating on bakeware wears out the same way it does on a frying pan, and for the same reasons - see how long nonstick lasts.

• No dishwasher unless the maker explicitly permits it. USA Pan publishes hand wash in warm water with mild soap.
• No metal. No knives cutting brownies in the pan, no metal spatula lifting cookies.
• No cooking spray. Aerosol sprays build a polymerized film on coated bakeware exactly as they do on frying pans, and it will not come off.
• No stacking without a divider. The rim of the pan above scratches the coating of the pan below. Paper towels are enough.

Glass: dishwasher yes, temperature change no

Glass is the easiest bakeware to clean and the easiest to break. It is dishwasher, microwave and freezer safe, and it is entirely non-reactive, so nothing you bake in it will stain it in a way soaking will not fix.

The failure mode is thermal shock, and washing is where it usually happens: a dish straight out of the oven into a sink with water in it. Let it cool on a dry towel or a rack first, every time. The full set of rules is in glass versus metal bakeware.

Storage, which quietly does most of the damage

Stacked bakeware scratches itself. Sheet pans stored flat in a pile grind grit between them; coated pans stacked rim-to-surface scratch each other; glass dishes chip at the rim, and a chipped glass dish is the one you should stop using.

Store flat pans on edge in a vertical divider. It protects the surfaces, it is faster to get one out, and in a small kitchen it recovers more space than anything else - a point made at length in cookware for a small kitchen.

If a pan is past saving, the bakeware set roundup and a broad Amazon search are the places to start on a replacement.