字幕表 動画を再生する 英語字幕をプリント You ever notice this instruction that's in nearly every baking recipe? Preheating your oven to 350 degrees is sort of a basic requirement for baking in America. Our ovens even do it automatically as we turn them on, but have you ever stopped and asked yourself ... What's so special about this number? I love to bake, but I'm certainly not a pastry chef, so let's meet someone with a bit more experience. This is Michael Laiskonis, the creative director at the Institute of Culinary Education. He's a pastry chef. So temperature is really important in baking not only to develop color and flavor, but also to control the moisture in our products. As the temperature rises and moisture is lost at the surface, we get browning and also the creation of flavor compounds that didn't exist in that product previously. This happens because of a chemical process known as the maillard reaction, which occurs when proteins and sugars are transformed by heat and moisture. When sugar molecules are exposed to the heat in your oven they start to reduce – or break down – and interact with the proteins. That's when you can see your pastry turning golden brown. But it's not just about that physical transformation. You can taste the effects of the maillard reaction too – that's what gives us the flavors of the golden crust on a piece of bread or a nice sear on a steak or that mellow richness of, say, caramelized onions. The trick behind that reaction is to find the perfect temperature that sets it into action without over or under-doing it. These recipes might make you think that Maillard reaction occurs at 350 degrees, but actually ... So these Maillard reactions tend to occur at a fairly low temperature – around 230 to 240 degrees Fahrenheit. You want to manipulate the rate at which this reaction occurs both at the surface and internally to get the results you want. If we bake too cool, the entire cookie, for example, will dry out before we get that surface drying that will lead to browning. If we bake things in too hot an oven, the opposite occurs and we get burning. To get it just right we preheat the oven to 350 degrees so the Maillard reaction has time to occur throughout the entire cookie. For most home cooks and to also account for the fact that everyone's oven is slightly different, I think 350 is a great benchmark to work from. It's a safe standard for most people, but the number can also be altered to yield slightly different results. Some pastry chefs might bake at 325 if they want a lighter colored cookie, and some push it to 375 for a crispier outside. A lot of things that contemporary bakers tend to forget is not too long ago, in history, we didn't have as much control over our ovens or being a pastry chef meant being able to build a fire and maintain an oven temperature. Before the 1900's, when ovens didn't have temperature regulators, recipe writers instructed bakers to “cook in a moderate” “hot” or “slow” oven depending on the food. After the second world war, the temperature gauge was developed and it became widely popular across households. Modern ovens typically ranged from 200 to 550 degrees, so over time, recipe writers converted these temperature guidelines to actual numbers -- they settled on the 350 mark for “moderate” which was the sweet spot for baking. Using these more specific numbers is really a result of better oven design and better oven control. And the more you understand about what goes on inside your oven, the better results you'll get. And who doesn't want a better cookie? Hey everyone, thanks for watching. If you're interested in more food content, head on over our sister channel Eater. They've got this cool series where they test out different kitchen gadgets and they recently put up a video on pressure cookers.