Science of cooking: The ultimate guide to saucepans

Science of cooking: The ultimate guide to saucepans

Ok, so I have a confession. Of all the random kitchen tools and gadgets I have (BBQs, pizza ovens, sous vide, fryers etc) the items I have most enjoyed receiving, and look forward to the most, have been one of two categories: Saucepans or knives.

Sure, cooking a pizza in a minute or two in a raging hot pizza oven, or low-and-slow smoking a rack of short ribs is a lot of fun, and incredibly satisfying. But for me, I think there is something about pans. Maybe it’s that I turn to them more than any other tool in the kitchen. Day after day, they are there, and good pans can change a dish. The sear that I get on the skin of a chicken thigh for a quick weeknight meal when it hits my cast iron skillet. The depth of flavour and richness you get from a slow-cooked stew in a casserole dish. The robust hardiness of a tri-ply stainless steel pan. They seem almost magic. To me at least.

If you are anything like me, over the years, you may have slowly amassed a kitchen full of gadgets and tools for a whole range of cooks and prep. Some get used regularly, others have barely made it out of their boxes and some are more decorative. My advice to people starting out in a new kitchen is always to invest in good knives and good pans. Good pans and knives can literally last a lifetime. So even if they seem expensive, compared to the ongoing cost replacing cheaper versions every few years it starts to look like a decent investment. Economics of the better investment aside, as well as durability you will get far better results from better pans, especially if you use the right pan for the right job. And the right pan for the right job comes back to science!

I know that some pans can be expensive. Prohibitively so, in some cases. There is definitely a strong case, that good pans can last a lifetime, if not generations, making them more economical long term, but there is still an initial (large) outlay of cost. Some times you pay more for a brand, sometimes you can get quality second hand.

1. Cheap Saucepans

Cheap saucepans will suffer from two faults; poor construction and poor material. A cheap saucepan will be made from a single, fairly thin piece of metal and the rivets holding the handle together are likely to loosen and eventually become unusable.

The problem with a single metal being used for the saucepan, is that there are lots of different properties of different metals that make for good saucepans and there is no one metal to rule them all (as we will eventually see when we come to the pans made of several materials, to take advantage of the differing beneficial properties of each).

That said, there is no reason you wouldn’t be able to cook great food in cheap pans, if you can’t afford an initial outlay on pans then do not be put off, the quality of the pan (or knife, or BBQ or any cooking tools) does not make the cook, so do not be deterred.

To be honest, I have several cheap pans. Sure, the worst of them suffers from the handle and sides getting stupidly (even dangerously) hot. But I still use it. It does a job, cooking peas, heating food, it’s fine - it was cheap and has actually lasted several years so far. I am pleased to have it in my cupboards for when I need more pans, but also glad its not my only pan.

2. Science of saucepan materials

2.1 Aluminium Saucepans

Aluminium conducts heat very well, which means it can heat up very quickly and also distributes the heat very evenly (because it conducts heat quickly, the entire base of the pan will quickly be heated up, so you get an even heat across the bottom, without hot/cold spots) - which are both good things.

However, there are downsides of these properties. They also result in aluminium not retaining heat very well (which can be a good thing if you want your pans to cool quickly, but that’s not often something we will be looking for). This is especially noticeable if you wanted to cook something with a good sear on it, like a steak. Drop a cold steak onto a hot aluminium pan and its going to loose loads of its heat energy, quickly. This makes it much harder to get a nice deep sear on food with an aluminium pan, as the base just looses its heat too fast.

A cheap saucepan made entirely out of aluminium, will also suffer from conducting the heat quickly throughout the entire pan, including up the sides of the pan and the handle, which can result in a saucepan that is impractical to use without permanent use of oven gloves (this is basically the case with one of my cheap saucepans I mentioned earlier).

Aluminium is a reactive metal, which means it can react with particular substances, specifically acidic foods such as vinegars or tomatoes, and can result in the food taking on a slightly metallic taste. However, most aluminium pans these days are anodised, which is a process that transforms them to a non-reactive material, so this shouldn’t really be an issue, but worth keeping in mind if you are looking at cheap or old aluminium pans.

2.2 Stainless steel saucepans

Stainless steel, on the other hand, is slower to heat and doesn’t distribute the heat evenly. This means you can have hotspots across the base of your pan, which can be easily noticed if cooking on a traditional gas ring hob - it will likely be a lot hotter around the ring of the hob where the heat is applied, and cooler in other parts. If you have a large stainless steel pan on a ring hob and simmer some food you may notice the simmering of bubbles specifically around the centre whilst the edges of the pan are cooler.

Steel, on the other hand, is far more durable to bumps and bangs than aluminium, and is also a non-reactive metal, so no issue using steel pans with any ingredients.

It’s not the worst metal for heat distribution, and between being non-reactive and fairly durable, its a fairly strong middle-ground option for cheaper pans.

2.3 Copper saucepans

Copper is a bit like supercharged aluminium - similar in their properties, it conducts and distributes well, resulting in evenly heating - but far out performs aluminium in both these regards. It is also a reactive metal like aluminium so not suited for acidic ingredients.

Two other things worth mentioning about copper that stand out:

  • It’s ever so trendy - the colour and finish of copper pans have a vintage retro look and do look good in a kitchen
  • It’s more expensive

Because of these properties, you may have seen copper bottom pans - regular looking pans that have a brown copper base underneath the pan. In these pans, the bulk of the pan will likely be made with another metal such as steel, a non-reactive metal, but the copper lined base ensures an even spread of heat from the heat source across the base of the pan, so the inner base of the pan is heated by the copper rather than the the heat source, giving a more even cook. We will get into more on this kind of technique in the next section on tri-ply, but this is essentially a two-ply pan.

2.4 Tri-ply saucepans

Tri-ply is a further combination of materials, often a sandwich of steel and aluminium - these pans benefit from the good properties of the metals to make superior pans. A durable non-reactive metal such as steel for the outer layers of the pan make it able to cope with high heat, acidic ingredients and also ensures it holds its heat well, with a middle layer of aluminium to ensure even heat distribution across the base.

A set of well-constructed tri-ply saucepans is my recommendation to anyone in need of saucepans. They can withstand high and low heat cooking, cooks evenly, dishwasher safe and can last a lifetime.

Another thing to keep in mind when talking about tri-ply saucepans is the term fully-clad. Fully clad means the three layer sandwich of metals will be throughout the entire pan, from the base and up the sides. Non fully clad tri-ply pans will likely have a tri-ply base to the pan but thinner sides made of just one metal (stainless steel), these may be cheaper and provide a good consistent heat across the base of the pan, but will not have the added benefit of all round heating. You might not notice too much difference cooking on the hob with fully-clad vs non, but if you transfer it to the oven, the fully-clad will come in to its own a lot more like a good casserole dish.

2.5 Cast iron saucepans

Of all the single-metal pans discussed so far, none of them have been put in a particularly favourable light in terms of my recommendations. But cast iron holds a special place in my heart, as I’m sure it does many (I have written entirely about the science of cast iron pans before, too).

Cast iron is a reactive metal, so not suitable for acidic ingredients. It also takes a long time to heat up, so as a result doesn’t heat very evenly, although given enough pre-heating time the heat will eventually distribute throughout the pan. Similar to other single metal pans, the heat will also conduct to the handle of the pan making it impractical to use without oven gloves (and as cast iron skillets are usually moulded single pieces of iron, the little handles will inevitably get very hot).

However, the reason cast iron skillets have endured in popularity, as well as the demand for cast iron BBQ grills and planchas, is their ability to sear meat. Because cast iron retains heat and energy so well, it can give an incomparable sear on a piece of meat. That deep brown, delicious finish on a steak requires high heat searing, and this is where cast iron really shines.

As mentioned earlier, if you get an aluminium pan nice and hot, and then thrown on a nice juicy steak, as soon as that steak hits the pan a lot of the heat from the pan is lost and the temperature of the pan will drop considerably - this makes it very hard to get a good sear on the steak from an aluminium pan. Do the same on a cast iron pan, and the pan will hardly register a drop in temperature at all, like a good old work horse, it just powers through holding its temperature and searing your steak like a champion.

For me there is nothing quite like the sizzle of cooking with cast iron, maybe it’s in part the nostalgia of the pan so steeped in tradition, but it’s definitely at least a little bit that I enjoy the science of why it cooks so well (I’m a nerd though).

2.6 Enamelled cast iron pans

The equivalent of the tri-ply, I’d recommend everyone get an enamelled cast iron casserole dish. It is basically what it sounds like - a cast iron casserole dish, with an enamelled finish. Probably the most famous and recognisable of these pans it those from Le Creuset (the pan in the header photo), and from the price they definitely know it. These pans will last forever. Incredibly durable, and if you are cooking slowly in an oven, nothing comes close. The high heat energy from the cast iron, with the enamel coating making it a lot more non-stick and non-reactive for acidic sauces. Another of my favourites to cook with.

As these are relatively simple dishes, in terms of materials (a single, solid piece of cast iron, coated in enamel), you really are paying for brand here. Get a halfway reputable enamelled cast iron pan and it will serve you well, for a long time.

Photo by Becca Tapert on Unsplash