Science

In this chapter

• Acidity — The sour taste and low pH that shape fermentation, gel set, cheese texture, wine balance, and which canning process is even legal to use.
• Caramelization — Sugar itself browning and changing aroma when heated, without needing protein — a different browning from Maillard crust on bread.
• Collagen — The connective-tissue protein in meat, skin, and bone that moist heat can unwind into gelatin — why a tough cut softens in a braise and a chilled stock can stand up.
• Crystallization — Dissolved sugar or salt coming back as crystals — a grit in jam, a crust of brine — when water, agitation, or leftover grains give them a place to grow.
• Denaturation — Proteins losing the folded shape that kept them soluble or active, so milk can curdle, an enzyme can stop, or gluten can be treated as a network instead of a bag spec.
• Emulsion — Two liquids that do not dissolve in each other — fat and water — held as one food for a while, as in milk, until gravity, heat, or acid pulls them apart.
• Enzymes — Proteins that speed specific changes in food — ripening, dough extensibility, cheese ripening — until heat or other conditions stop them.
• Evaporation — Water leaving food as vapor — the kettle concentrating jam, the dehydrator shrinking fruit, the oven drying a crust after steam.
• Fat — The greasy phase in milk, butter, cheese, and oil — flavor, calories, and a separate liquid that emulsions have to hold.
• Fermentation — Microbial transformation of food, producing gas, acid, alcohol, and flavor in bread, cheese, wine, and beyond.
• Foam — Gas trapped in a liquid or protein film — whipped egg, a mousse, the open crumb of bread — until fat, heat, or time collapse the bubbles.
• Gelatinization — Starch granules taking up water and swelling under heat until a sauce thickens or a crumb sets — a heat-and-water change, not a gluten network.
• Gluten — The protein network formed when wheat flour is hydrated and worked, giving dough its extensibility and gas-holding strength.
• Heat coagulation — Proteins setting or clumping because they were heated — a soft egg, a curd that was cooked in the vat — distinct from acid or rennet coagulation.
• Heat transfer — How heat actually reaches food — water, steam, metal, air, or the mixer itself — so a crumb sets, a crust dries, or a vegetable blanches.
• Lactic acid bacteria — Bacteria that produce lactic acid (and often acetic acid) in sourdough, cheese, and other fermented foods.
• Maillard reaction — The browning and savory aroma that develop when proteins and sugars meet dry enough heat — distinct from sugar-only caramelization, and not a temperature you should invent.
• Milling — The mechanical separation of a wheat kernel into flour streams, bran, and germ — a process that decides what bakers later call “flour.”
• Osmosis — Water moving toward a higher concentration of dissolved sugar or salt, which is how a pickle weeps, a brine salts a cheese, and a jam kettle concentrates fruit.
• Oxidation — Oxygen changing pigments, oils, and wine until color bleaches, fat smells rancid, or a grade standard records flavor defects.
• Pectin — A plant polysaccharide that can gel fruit, sugar, and acid into jam and jelly when concentration and pH allow the chains to network.
• pH — A 0-to-14 scale of how acidic or basic a watery food is — a meter reading, not the sour taste, and the number that splits acid foods from low-acid foods at 4.6 in U.S. canning rules.
• Protein — The polymers in flour, milk, egg, and saliva that build gluten, set curd, hold foams, and make tannin feel dry — not one substance and not a single cooking method.
• Staling — Bread losing the eating quality it had when it cooled — crumb firming, crust going leathery — a keeping problem, not a food-safety clock.
• Starch — The carbohydrate that fills wheat endosperm and thickens, gels, or feeds fermentation once it is hydrated and heated — not the same network as gluten or pectin.
• Syneresis — A gel squeezing out liquid it used to hold — whey on yogurt, whey after a curd is cut, weeping from a jam — shrinkage of a network, not a new recipe.
• Water activity — How much water in a food is actually available for microbes and enzymes to use — lowered by drying or by binding water with sugar or salt, not the same number as “percent moisture.”
• Wild yeast — Yeasts captured from flour, air, and fruit that leaven sourdough and other spontaneously fermented foods.