Kitchen science

What happens to food when you cook it, and why browning, brining and resting work.

AcidAcid is the sour taste from lemon, vinegar, wine, tomatoes and yogurt. A splash at the end brightens a flat dish and balances salt, fat and sweetness.
BrineA brine is salt dissolved in water. Soaking meat in it for hours makes it juicier and seasons it through. Here are the ratios, times and safety rules.
CaramelizationCaramelization is the browning of sugar under heat, which turns it from plain sweet to rich, nutty and a little bitter. It is not the Maillard reaction.
CollagenCollagen is the tough protein in meat's connective tissue. Slow, moist cooking turns it into gelatin, which makes braised meat tender and stock set.
CurdleCurdling is when milk, cream or egg sauces separate into lumps and thin liquid. It happens from too much heat or acid. Here is how to stop and fix it.
CureTo cure is to preserve meat or fish with salt, often with sugar, nitrite or smoke. It draws out water and adds flavor, as in bacon and gravlax.
DenaturationDenaturation is when heat, acid, salt or whisking makes proteins unfold and change shape. It is why eggs set, meat firms up and egg whites whip into foam.
Dry brineTo dry brine is to salt meat ahead of time and leave it uncovered in the fridge. It seasons deeply, keeps meat juicy and gives crisp skin, with no bucket.
EmulsionAn emulsion is a mix of oil and water, which normally do not blend, held together as tiny drops. Mayonnaise and vinaigrette are emulsions.
FermentationFermentation is when yeasts or bacteria break down sugars and change food. It raises bread, sours sauerkraut and yogurt, and makes wine and miso.
GelatinizationGelatinization is when starch grains soak up water and swell in heat, thickening sauces, setting puddings and softening rice and pasta. Here is why.
GlutenGluten is the stretchy protein network that forms when wheat flour meets water. It gives bread its chew and structure, and too much makes cakes tough.
Lacto-fermentationLacto-fermentation preserves vegetables with salt and the lactic acid bacteria on them. It makes sauerkraut, kimchi and sour pickles with no vinegar.
LeaveningLeavening is what makes dough and batter rise, such as yeast, baking soda, baking powder, steam or whipped air. Here is how each works and when to use it.
MacerateTo macerate is to soak fruit in sugar, alcohol or juice so it softens and releases its own syrup. It takes 15 minutes to a few hours and needs no heat.
Maillard reactionThe Maillard reaction is the browning of protein and sugar under heat. It gives seared steak, bread crust, roasted coffee and fried onions their flavor.
MarinateTo marinate is to soak food in a seasoned liquid of acid, oil, salt and aromatics before cooking. Here are safe times and why longer is not always better.
NixtamalizationNixtamalization is cooking dried corn in an alkaline solution, usually lime. It loosens the hulls, adds nutrition and makes masa for tortillas and tamales.
OxidationOxidation is what happens when food reacts with oxygen in the air. It turns cut apples and avocados brown and makes oils and nuts go rancid over time.
PickleTo pickle is to preserve food in an acidic liquid, either vinegar or a salty brine that ferments. Quick fridge pickles are ready in an hour or less.
Resting meatResting meat means leaving it to stand after cooking before you slice it. Juices settle, the center finishes cooking and less liquid ends up on the board.
RetrogradationRetrogradation is when cooked starch cools and firms up again. It is why bread goes stale and cold rice hardens, and why day-old rice fries better.
SeizeChocolate seizes when a few drops of water turn it from smooth and melted to thick, grainy and stiff. Here is how to avoid and rescue it.
Split sauceA split sauce is an emulsion, like mayonnaise or hollandaise, that has separated into fat and thin liquid. Here is why it happens and how to fix it.
UmamiUmami is the savory, meaty taste found in Parmesan, soy sauce, tomatoes, mushrooms and broth. It is one of the five basic tastes.