The concave in our pans - why it's important!

As we cover below there must be a degree of concave when cold, or every pan would bow out convex when exposed to concentrated heat. If other pans are truly quality-made, you will find that they all also have a slight concave, as this is an engineering ideal for quality materials and longlasting designs.

If you are still finding that oil and liquids are pooling around the edges of your pan when you cook, we recommend the 2 following tips:

1. Ensure that the element you are using on your stovetop is correctly matched to the size of your pan. If your element is smaller than the base diameter of your pan, it can create a hotspot in the center of your pan and cause it to heat unevenly, and therefore not expand and flatten out correctly.
2. Make sure you are allowing your pan to heat gradually on a lower heat. If you heat your pan too quickly and on a high heat, it can also cause your pan to heat unevenly, and therefore not flatten out in the way it is designed to. Low and slow is best :)

Solidteknics pans are designed with the correct amount of concave to compensate for the natural expansion/contraction of metal when heated/cooled. This is common with all quality, heavy-based pans. We're mechanical engineers and calculate this concave very carefully for each pan model, knowing that the metal will expand (and therefore flatten out) at high temperatures.

There must be a degree of concave when cold, or every pan would bow out convex when exposed to concentrated heat, and become a 'spinner' on glass cooktops. Should every pan flatten out completely when warm? No. Each pan model's concave is calculated to approach flat under the most common heating conditions, the problem is, every cooking environment is different. Put simply, even when the ultimate temperature is the same, cooktops deliver heat in various forms (e.g. gas, IR, induction, etc), and hot zones come in many different sizes (e.g. very wide gas vs very narrow for cheap induction).

We must engineer for the average, knowing that there will always be slightly different movements according to cooking environment and heat source, and the pans won't always flatten out for everyone. They are designed to approach flat for most people, which is far better than the convex that would otherwise occur in every pan. Once pans become 'spinners' they are generally unusable, and certainly undesirable. Ultimately, the small amount of concave that may linger after heating doesn't affect cooking performance, even on flat infrared or electric hot plates, as all Solidteknics cookware is very conductive.

However, it is important to note that there will be uneven movement/expansion of the base if using large pans on small, high power, concentrated hot zones; when the centre of the pan's base is forced to move/expand a lot faster than the outer edges (this can result in permanent warping). Therefore, it is important to match the burner/hot zone size correctly to the size of the pan you are using. When that isn't possible, always allow more time for your pan to slowly pre-heat at a lower temperature, so the heat can conduct gradually from the hot areas to the cool areas without rapid expansion.

Similarly, induction cooktops can put out a lot of heat instantly, and cheaper models often won't heat properly across the zone they're supposed to, but rather concentrate heat in a much smaller area, making it tricky to match the correct heating zone to the size of the pan. Therefore, we always recommend warming your pan on a lower temperature, and never using anything higher than a medium heat setting for AUS-ION™ or nöni™ cookware which is highly conductive. A high stovetop heat simply isn't required to get a hot pan and it is far better to spend a little longer pre-heating your pan at a lower temperature than to deal with any unresolvable issues that may result from thermal shock.

(Oven-like environments are different as the whole pan heats simultaneously, allowing the metal to expand uniformly; meaning our pans can withstand very high temperatures in pizza ovens and the like.)

Here's another great article from Prudent Reviews on why cookware can warp.

Please watch the video below which explains and demonstrates normal concave:

You can read more about why quality cookware manufacturers pre-concave their bases - see here.

If you believe your pan has more than the normal degree of concave after checking the base with a straight edge and seeing more than a 3mm gap, please let Solidteknics know via email info@solidteknics.com, with photos, so we can determine if your pan is one of the rare ones that has become warped due to accidental misuse.

Don't worry though, this really isn't a common occurrence at all. To put warping into perspective, Solidteknics have shipped well over 100,000 pans, and only replaced around three dozen in total for genuine warping.