It’s hard to imagine…

…anyone consciously choosing contaminated food, right? We care about where our food comes from and how well it’s been handled in its travels, and we’re starting to think more carefully about the pots and pans in which we prepare that food too.

Brown not Black

The Maillard reaction, is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. This reaction takes off at cooking temperatures of about 325℉. Above 355℉ another set of reactions called pyrolysis takes over and food goes from browning agreeably into burning ruinously. With a melting point of 425℉, tin is far from being “too fragile” for browning, indeed, its thermal and non-stick properties allow for even browning without drying out or burning. A simple awareness about the tool in which food is being cooked can help keep dinner from becoming charcoal. You can brown to your heart’s content in tin – it’s clingy in all the right ways.

Pure tin means pure food

Pure tin is, for cooking intents and purposes, molecularly and chemically inert – it reacts very little to variations in pH and does not impart either flavor or volatile compounds to your food. Peppers, herbs and all other foods maintain their delightful flavor and texture.  Tin does very slowly oxidize, turning darker as it hardens with use, and it does impart a minuscule amount of those flavorless oxides to acidic foods, much as iron imparts oxides of iron when you cook in it. The net result of cooking in tin is you get a tiny bit more tin in your diet, an essential micro-nutrient not easily absorbed and authoritatively considered non-toxic. Historic sources of dietary tin, tin-lined copper pots and (more recently) tinned cans, started being usurped by iron, aluminum and enameled steel over a century ago (today a so-called “enamel-lined” can is very likely lined with bisphenol A-based plastic).

The worst that could happen using tin-lined copper? You get a little more of a micro-nutrient you probably lack, and your sauces go three-star.

Why food doesn’t brown well in PFA-coated pans

Perhaps you’ve noticed that on common non-stick surfaces water beads up. One of the reasons PFA (poly- and perfluoroalkyl polymer)-based coatings don’t brown well is that the water in food does not sheet, it beads. In fact, one of the ways to tell your PFA coating has degraded is that water begins to sheet rather than bead. The theory goes something like this: The relative failure of PFAs to brown food under heat indicates you have a very thin layer of water consistently between your food and the cooking surface.

Normally heat would tend to push water further into food (searing 101: moist on the inside, crunchy on the outside), but when cooking on PFAs normal thermal effects on water are partly compromised owing to the free electrons fluorine (the F in PFA, and also in its toxic byproduct, perfluorooctanoic acid, or PFOA) makes available for molecular bonding with the hydrogen in water.

Heat apparently activates more of these free fluorine electrons, thus creating a greater hydrophilic (hydrogen-bonding/water-attracting) effect. Water is drawn to create a barrier layer between the pan surface and your food, which has to literally steam a good deal before it dries out enough to begin to brown.

While it may be problematic for quality cooking, the hydrophilic quality of fluorine does keep the surface temperature of your PTFE lining closer to the boiling point of water, 212℉, which is below the level most authorities believe PTFE begins to outgas PFOA. So, by browning poorly PTFE does keep itself from hurting you.