Scope. This page provides a controlled reader-run protocol and does not claim site-run measurements. For cooking, cooling, storage and reheating, follow the current official guidance linked on the page.
Pan arguments are conducted almost entirely without evidence. One person swears by cast iron, another by carbon steel, a third insists that anything other than heavy stainless is a compromise, and none of them has measured a single thing. The arguments are enjoyable and they settle nothing, because the properties being argued about are measurable and nobody measures them.
There are three measurements that decide how a pan behaves. Everything else is handle comfort, weight, price and habit.
The two properties that get conflated
Before the protocol, one distinction has to be made properly, because almost every pan discussion online collapses it and the collapse is why the discussions go nowhere.
Conductivity is how quickly heat moves through the material. A highly conductive pan spreads energy sideways fast, so a hot spot under one part of the base gets shared out across the base quickly.
Thermal mass is how much energy the pan stores for a given change in temperature. It is a function of the material's heat capacity and of how much material there is. A high-mass pan takes a lot of energy to warm up and gives a lot of energy back to whatever you put in it.
These two are not the same property, they are not correlated in any convenient direction, and they pull against each other in use.
- High conductivity gives you evenness and responsiveness. Turn the heat down and the pan follows you quickly.
- High mass gives you stability and recovery. Put cold food in and the pan barely notices. It also means that when you turn the heat down, the pan carries on delivering heat for a while, because the energy is already in the metal.
A cook who wants a pan that responds instantly to the dial and a pan that never drops when food goes in is asking for two different pans. Most of the confusion in pan advice comes from people who have experienced one of these properties and generalised it into a claim about the whole material.
This article does not reproduce handbook conductivity or heat-capacity values. It treats pans as complete cooking objects—material, thickness, mass, construction and geometry together—and compares them only by curves you measure yourself.
Thickness beats brand
The second thing that has to be said before you measure anything: within a material, thickness matters more than the difference between brands.
A thick pan and a thin pan of the same metal behave differently enough that treating them as the same category is misleading. Two pans of the same metal and the same base thickness from two different makers will behave very similarly, whatever the price difference between them.
This has a practical consequence for how the test is designed. Comparing "cast iron" against "stainless" is only meaningful if the thickness variable is controlled or at least recorded, so measure and record the base thickness of every pan you test, and qualify every conclusion by it. It also has a consequence for the reader: if a conclusion here favours a material, the useful action is to buy a thick example of that material at whatever price, not to buy a particular badge.
The three measurements, and why these three
The site's angle is cooking below the boil, so the measurements are chosen for what matters in that range rather than for what matters when searing.
| Measurement | What it tells you | Which property it exposes |
|---|---|---|
| Heat-up | How long the pan takes to reach a target, and whether it overshoots | Mass, mostly |
| Evenness | How much the surface temperature varies from edge to centre at a held target | Conductivity, mostly |
| Recovery | How far the pan drops when cold food goes in, and how long it takes to come back | Both, in opposition |
Three measurements. Four materials. No reverence for any of them.
Measurement 1: heat-up
The pan goes on a hob at a stated, fixed setting, empty, and surface temperature is logged at fixed intervals until it stabilises. The output is a curve, not a single number.
What the curve shows that a single number cannot: whether the pan approaches the target smoothly or overshoots and settles back, and how long the settling takes. Overshoot is the reason so many gentle dishes fail in the first two minutes. The cook sets the dial to what they believe is a low setting, puts the food in when the pan "looks ready", and the pan is still climbing.
Recorded per pan: base thickness, mass, hob type, ambient temperature, the full logged curve, time to target, overshoot magnitude, and settling time.
Measurement 2: evenness
The pan is brought to a stated target and held there, and surface temperature is read at a fixed grid of points from centre to edge. The output is a gradient.
This is where conductivity shows itself most clearly, and it is the measurement most relevant to why food behaves inconsistently across a pan. When one piece of food is browning and the piece next to it is still pale, the pan is telling you about its gradient. We come at the same problem from the food's side in why your vegetables steam instead of browning.
One variable to record that almost never appears in these comparisons: hob type. A gas ring, an induction coil and a radiant electric plate apply heat to different parts of the base in different patterns, so evenness is a property of the pan-and-hob pair rather than of the pan alone. Any single-hob result is stated as such.
Recorded per pan: the target held, the grid of readings, the edge-to-centre spread, hob type, and whether a lid was fitted.
Measurement 3: recovery after a cold addition
The pan is held at a stated target, a stated mass of a stated cold ingredient at a stated starting temperature goes in, and temperature is logged continuously through the drop and the return.
This is the measurement that matters most in real cooking and the one nobody publishes. It produces two numbers: the depth of the drop and the time back to target.
It is also where the mass-versus-conductivity tension becomes concrete. A heavy pan should drop less because it has more stored energy to give. A conductive pan should return faster because it moves energy from the hob to the food more efficiently. Which effect dominates is an empirical question, which is exactly why it is worth measuring rather than arguing about.
Recorded per pan: the held target, the addition mass and starting temperature, the full logged curve, drop depth, and time to return.
The four materials
Four are worth comparing, defined by their thermal behaviour rather than by their reputation.
- Cast iron. Thick, heavy, high mass. Its handling characteristics are a separate subject from its thermal behaviour and we are not covering them here.
- Carbon steel. Steel, typically thinner than cast iron, so lower mass for the same footprint.
- Stainless. Almost always clad or with a disc base, meaning a layer of a more conductive metal is bonded into the construction. Record the construction per pan, because it dominates the behaviour.
- Enamelled cast iron. Cast iron with a glass surface layer. We treat it as a fourth material because the surface changes and because it is bought as a distinct thing, not because we have any view about the coating.
No seasoning content appears in this post. Whether a pan is seasoned, how it was seasoned and what that does to sticking are questions about surface behaviour, not thermal behaviour, and they belong in why everything sticks to the pan at low heat. Mixing the two subjects is how pan discussions turn into folklore.
No claims about coating chemistry or coating safety appear here either, in any direction. We have no data, it is outside what a thermal bench can tell you, and a pan test is not the place to speculate about it.
How each pan was obtained
If you record or share a comparison, state on every row whether the pan was purchased, gifted or loaned. It changes nothing about the physics and a great deal about how a reader should weigh the verdict; our disclosure policy applies the same rule to anything this site tests.
Rank no pan by brand, and keep brands out of headings, table headers and verdicts. If a specific construction detail turns out to explain a result, name the detail. The badge is not the explanation.
Reader worksheet
Use these as reader worksheet fields. Record values only from your own runs.
Heat-up curves
Record four curves, one per material, with base thickness and mass stated for each pan, plus time to target, overshoot and settling time.
Evenness at a held target
Record grid readings per pan and the edge-to-centre spread, stated per hob type.
Recovery after a cold addition
Record drop depth and return time per pan, with the full logged curve.
What each material is genuinely best at
Answer this from your three tables and from nothing else, and phrase it as "this pan did X in this measurement", not as "this material is better".
The honest expectation, stated in advance so that your results can contradict it: each material will win at least one measurement and lose at least one, because the properties genuinely trade off against each other. If one material sweeps all three, treat that as a surprising result and check the thickness of the pans involved before concluding anything from it.
Which matters most for cooking below the boil
This is the section the whole post exists for, and it is where this site differs from a general pan comparison, so the reasoning gets stated in advance.
Below the boil, the demands on a pan change in a specific way. Searing wants a pan that holds a lot of energy and delivers it fast into a cold surface. Gentle cooking mostly does not. Gentle cooking wants:
- A low, stable floor. The ability to sit at a low target without cycling above it. This is more about the hob than the pan, which is why it gets its own treatment in how to hold a pan at 60°C on equipment that does not want to, but pan mass changes how much the hob's cycling reaches the food.
- Evenness at low targets. A gradient that is tolerable at high heat can be decisive at low heat, because the whole working window may be only a few degrees wide. A pan that is uneven across its base at a low held target is cooking two different dishes at once.
- Predictable response to the dial. When you turn a gentle dish down because it is climbing, you want the pan to follow. A high-mass pan will not, and that lag is a genuine cost that never appears in the "buy heavy" advice.
Note that point 3 argues against the high-mass materials that most pan advice recommends by default. That advice is written by people cooking at high heat, where mass is the property that matters, and it has been repeated into a general rule that it was never entitled to be. Whether your own measurements support that scepticism is a question for the bench, not for this paragraph.
FAQ
Is a heavy pan always better? No, and the belief that it is comes from high-heat cooking. Mass buys stability and costs you responsiveness. Which of those you want depends on what you are cooking, and for a lot of gentle work the responsiveness is worth more.
Does the brand matter? Within a material, much less than thickness. Two pans of the same metal with the same base thickness will behave very similarly regardless of what is stamped on the bottom. Buy thickness, not badges.
Which pan should I buy first? That question is answered on its own terms in what to buy first, and the answer does not begin with a pan.
Why not test non-stick? Because the interesting variable in a non-stick pan is the surface, not the metal underneath, and this is a thermal test. Surface behaviour is a separate subject, covered from the food's side in why everything sticks to the pan at low heat.
In Plain English
Pans differ in two properties that are constantly mixed up. Conductivity is how fast heat spreads through the metal, and it buys evenness and responsiveness. Thermal mass is how much heat the metal stores, and it buys stability and recovery when cold food goes in. You cannot have the maximum of both, and most pan advice recommends mass because most pan advice is written about searing.
Within any one material, thickness changes behaviour more than the brand does.
This helps you if you are about to spend money on a pan, or if you own several and cannot predict which one to reach for. Use it at the point of that decision: ask whether the dish needs a pan that follows the dial or a pan that ignores cold food, because those are different pans.
What to do next: do not buy anything yet. Measure how your existing pans behave on your own hob using the same three questions, and note which of them overshoots when you turn it low. That single observation explains more failed gentle dishes than any purchase will fix.
Where to go next
Keep the protocol, raw logs, and each pan's obtained-status with any result.
Before you buy anything, the more useful reading is everything in the heat section, which covers what your hob is actually doing at each setting. On most domestic equipment the hob is a bigger source of error than the pan, and it costs nothing to find out.
Related technique: Twelve Ingredients Worth Paying More For, And Eight That Aren't.