Why do most recipes cook at an oven temperature of 180 degrees?
So how did oven temperature of 180 degrees become the sweet spot – in so many recipes, and as an oven preset – in the first place?
Well, not all ovens are the same.
Different ovens set to the same temperature can vary by as much as 32°C, according to an investigation by Cook’s Illustrated magazine. Even when an oven says it’s at 180°C, the temperature can shift up and down quite a bit – dipping to 150°C, rising to 200°C – as something’s cooking. Plus, some ovens simply wear out over time.
The magic of cooking at an oven temperature of 180 degrees isn’t magic at all, but chemistry. It is, for example, the level associated with the Maillard Reaction, the chemical process that gives so many foods a complex flavour profile – and an appealing golden-brown hue – when sugar and protein are heated together just so. The Maillard reaction is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, pan-fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and many other foods, undergo this reaction. It is named after French chemist Louis-Camille Maillard, who first described it in 1912 while attempting to reproduce biological protein synthesis.
Without Maillard chemistry we would not have a dark bread crust or golden brown turkey and our cakes and pastries would be pale and anaemic, and we would lose the distinctive colour of French onion soup according to the authors of a Royal Society of Chemistry book about the reaction,
Many chefs aren’t fixated on any one temperature, and instead think of their craft in terms of ranges: “Really low, under 135°C degrees; moderate, between 135°C and 176°C; high, over 176°C but under, say 218°C; and maximum,” the cookbook author Mark Bittman once told Slate. It wasn’t until the 20th century that recipes routinely included precise temperatures – even in the 1950s, it was common to see terms like “slow oven” and “moderate oven” in place of any number. The very concept of cooking at a constant and precise temperature is technologically driven, an extension of a device that seemed miraculous at the time it was introduced: The regulator.
The device was located on the oven, and usually involved a wheel or pointer you could turn to the temperature of your choice. This was connected to a thermometer-and-valve contraption that would expand as the oven got hotter, and prevent the temperature from going up when the upper limit was reached. Today, the ability to set a constant temperature seems so inherent to the concept of how an oven works – it’s just what ovens do. But when regulators were new, they were a marvel of automation.