The right pan to roast vegetables

Quick answer

To roast vegetables, use a 18 inch bare or anodised aluminium sheet pan. Bare aluminium browns more evenly than anything else at the price, and a single layer with space around each piece is what produces colour.

The material properties are published. Which material suits which job is reasoned from those properties and from common kitchen practice.

Materials for this job, and how each behaves
MaterialConductivityHeat retentionReactiveSuits this job
Tri-ply stainless clad237 W/m-KmediumNoWorkable, with compromises
Bare cast iron52 W/m-Kvery high, because of mass rather than conductivityYesWorkable, with compromises
Carbon steel50 W/m-Kmedium, well below cast iron because it is much thinnerYesWorkable, with compromises
Enamelled cast iron52 W/m-Kvery highNoWorkable, with compromises
PTFE nonstick237 W/m-KlowNoWorkable, with compromises
Bare or anodised aluminium237 W/m-KlowYesBest choice
Copper, lined401 W/m-KmediumNoWorkable, with compromises
Plain stainless steel16 W/m-KlowNoWorkable, with compromises
What this usually means buying

Nordic Ware Naturals Quarter Sheet, 2-Pack, Natural

$21.24Check pricePrices change often

Why bare or anodised aluminium for this?

Bare aluminium browns more evenly than anything else at the price, and a single layer with space around each piece is what produces colour.

Bare or anodised aluminium conducts at about 237 W/m-K and holds heat low. Aluminium conducts about fifteen times better than stainless, which is why almost every good stainless pan has aluminium hidden inside it.

Why size matters as much as material

A 18 inch pan measures 18 inches across the rim and about 16 inches across the flat base, giving roughly 201 square inches of usable cooking surface. That holds about 8 seared portions without crowding.

Crowding is the most common way this job goes wrong. Food releases moisture, and if there is not enough surface for that moisture to evaporate it pools and the food steams at roughly the boiling point of water instead of browning. Turning the heat up does not fix it, because the limit is evaporation rate rather than energy input.

What else will work, and what it costs you

Most of the other common materials will do this job to some degree, with a specific compromise each time. A thin conductive pan responds faster and loses temperature the moment cold food lands. A thick iron pan holds temperature and is slow to react when you want to pull the heat back. A coated pan releases food reliably and cannot be run at searing temperatures. Knowing which compromise you are making is more useful than owning the theoretically perfect pan.

One genuine constraint with this material: Bare aluminium reacts with acidic and strongly alkaline food, which can discolour both the pan and the food. Anodising largely removes this. Induction compatibility: no. Aluminium is not ferromagnetic, so an induction hob cannot couple to it at all unless a steel plate is bonded on.

Pans to roast vegetables

Common questions

What is the best pan to roast vegetables?

A 18 inch bare or anodised aluminium sheet pan. Bare aluminium browns more evenly than anything else at the price, and a single layer with space around each piece is what produces colour. Size matters as much as material here, because crowding causes more failed results than the wrong metal does.

Can I use a different material?

Yes, with a known compromise. Bare or anodised aluminium is chosen here because bare aluminium browns more evenly than anything else at the price, and a single layer with space around each piece is what produces colour. Other materials will cook the food safely and will change the result: a thinner pan loses heat faster, a coated one cannot be run as hot, and a reactive one limits how long acidic ingredients can cook.

What size should the pan be?

18 inches across the rim, which gives about 201 square inches of flat cooking surface once the flared walls are accounted for. Remember a pan is measured across the rim, so the usable base is roughly 2 inches smaller.

Does this work on induction?

No. Aluminium is not ferromagnetic, so an induction hob cannot couple to it at all unless a steel plate is bonded on. A fridge magnet on the base settles it definitively: a firm grip across the whole base means it will work, a grip only in the centre means uneven heating, and no grip means it will not heat at all.

How hot can this pan go?

The material is good to about 500F. Uncoated aluminium bakeware handles normal baking and roasting temperatures without trouble. A nonstick coating on it, not the metal, is what sets a lower limit. The real ceiling for any assembled pan is the lowest of its cooking surface, its handle and, when covered, its lid, and the handle is very often the lowest of the three.