Food & Nutrition questions

139 fact-checked questions — tap any to predict the answer, then read why.

• Why can't a healthy adult cat live on dog food as its regular diet?
• Why can a little chili make food taste better?
• After sediment is removed from Champagne, why can winemakers add a little sugar-wine mix even to dry Brut styles?
• When the neck of a Champagne bottle is frozen and briefly opened during disgorgement, what actually pushes the yeast plug out?
• Before removing sediment from Champagne, why are the bottles slowly turned upside down over weeks?
• Why can Champagne gain bread-or-brioche aromas while resting on the dead yeast left after bottle fermentation?
• Why does pouring Champagne down the side of a tilted glass usually keep more fizz than splashing it straight into the middle?
• In a glass of Champagne, why do bubble trains often rise from the same tiny spots instead of appearing evenly everywhere?
• After Champagne yeast makes carbon dioxide inside a sealed bottle, why does much of that gas stay hidden in the wine until the cork is opened?
• Why does Champagne become bubbly while an ordinary red wine made from fermenting grapes usually stays still?
• Parmigiano Reggiano is made with milk, salt, and rennet only, so why can older pieces taste more savory or spicy without extra seasoning?
• Why does a Parmigiano Reggiano wheel wait until at least 12 months for the official selection mark instead of being fully approved when it is molded?
• How can Parmigiano Reggiano keep developing flavor after its starter bacteria have done their early acid-making job?
• How does the milky flavor of young Parmigiano Reggiano become nutty, spicy, or broth-like as the cheese ages?
• Why doesn't lactose in Parmigiano Reggiano keep decreasing as it ages from 12 to 36 months?
• Why can older Parmigiano Reggiano turn crumblier and grainier instead of simply becoming a harder block?
• When aged Parmigiano Reggiano has tiny crunchy white spots, what are those specks most likely telling you?
• Why does extended aging change Parmigiano Reggiano instead of merely storing the same cheese for longer?
• Why is steaming-hot sushi rice wrong for nigiri, even though cold rice is also bad?
• Why can fatty tuna on slightly warm sushi rice feel more buttery than the same fish served ice-cold?
• Why do sushi cooks mix the vinegar into the rice in a wide wooden tub, a handai, rather than a metal bowl?
• Why is short-grain Japanese rice better for nigiri than long-grain basmati, even before any fish is added?
• How does vinegar let sushi rice stay near room temperature during service without constant refrigeration?
• Why do sushi cooks season rice while it is hot, then let it cool before shaping nigiri?
• When cooked sushi rice gets cold in the refrigerator, which change inside the grains most directly makes it feel firmer?
• Why does good nigiri often use sushi rice cooled to about body temperature instead of refrigerator-cold rice?
• Why do white candy melts for coating cookies often set easily but feel waxier than real white chocolate?
• A white chocolate bar gets greasy gray-white streaks after warming and cooling, but still smells normal; what most likely happened?
• Why does white chocolate usually bring far less of cacao's gentle stimulant theobromine than dark chocolate?
• What gives real white chocolate its snap-and-melt feeling on your tongue even though it contains no cocoa powder?
• Why does white chocolate usually taste more like sweet cream than like bitter dark chocolate, even though both trace back to cacao beans?
• Why can a mostly sugar-and-milk white candy with only a trace of cacao fat fail white-chocolate label standards in both the U.S. and EU?
• What ingredient is essential for white chocolate to meet U.S. standards even though it lacks dark chocolate's brown cocoa solids?
• Why can milk fat sometimes prevent chocolate bloom but sometimes cause it?
• Why can a refrigerated chocolate bar turn grainy and pale after it warms to room temperature?
• If a filled chocolate develops a white haze, why might the filling be partly responsible even when the shell was decent chocolate?
• How can a little of certain phospholipids, a type of fat, help chocolate set with a smooth, glossy finish?
• In classic tempering, why does reheating chocolate after cooling not simply undo the whole crystallization step?
• Why does melted chocolate that is simply cooled back down often fail to regain a shiny professional finish?
• Why can a well-tempered chocolate bar look glossy and snap cleanly instead of setting dull and soft?
• Why does a chocolate bar that turns pale in storage usually remain safe to eat?
• Gelato looks soft in a shop display case, so what would make that same gelato turn brick-like after you bring it home?
• What mainly keeps a partially melted scoop of ice cream from collapsing right away?
• Why can airy ice cream melt slower even though it looks lighter?
• When ice cream is repeatedly warmed and cooled in shipping, what do small amounts of gums mainly fight?
• Why does ice cream stay scoopable at temperatures below 0°C?
• Why is factory-frozen ice cream smoother than melted ice cream refrozen in a home freezer?
• A grocery pint warms slightly, then freezes again. Why do the small ice crystals in the pint vanish?
• Melted ice cream refrozen at home tastes icy. What changed most?
• Why rest a cake before slicing instead of treating 'out of oven' as finished?
• Why can a sea-level cake recipe fall in a mountain kitchen?
• Why can the middle of a cake collapse while the edges look baked when the same batter is baked in a deeper pan?
• Why can an early oven-door peek sink a delicate cake before it is done?
• What turns the whipped egg bubbles in a foam cake into a sliceable sponge?
• Why can cutting sugar make a cake dense instead of simply less sweet?
• Why can extra baking powder make a cake taller in the oven but flatter later?
• Why does a cake that puffs up in the oven sink as it cools?
• Why isn't fresh pasta automatically better for al dente spaghetti?
• Why does stirring pasta in the first few minutes keep it from sticking better than adding oil?
• Salting pasta water barely changes boiling point. Why still do it?
• Why can a splash of pasta water make oily or cheesy sauce cling to noodles?
• Why can al dente pasta raise blood sugar more slowly than mushy pasta?
• Why does dried durum-wheat pasta keep a firmer al dente bite than many soft noodles?
• Why does spaghetti turn sticky and limp when it keeps boiling past al dente?
• When raw spaghetti cooks to al dente, what happens to its starch?
• Why can the same oxygen make an open bottle of red wine taste nicer tonight but worse tomorrow?
• Why does a rich Chardonnay sometimes improve with air while a fresh Sauvignon Blanc can lose its snap?
• Why is letting sparkling wine sit open to 'breathe' usually a bad idea?
• Why should an old red be decanted gently when a young red gets splashed?
• At dinner, a young Cabernet feels less sandpapery after some air. What changed most in the wine?
• A red wine smells like burnt match or rotten egg. Why can 10 minutes in a glass help?
• Why does pouring red wine into a wide decanter change it faster than just pulling the cork?
• Dry-aged beef is already much tenderer after two weeks, so why do producers keep aging it for weeks longer?
• Why age a whole rib section instead of a single steak at home?
• Why can vacuum-sealed wet-aging tenderize beef yet usually cost less than dry-aging?
• Why does a dry-aging room sit near 80% humidity, not bone-dry?
• Why can pale mold on dry-aged beef be useful during aging instead of just a sign of spoilage?
• Why does a dry-aged ribeye feel more tender even though it loses water?
• Dry-aged steak costs far more before cooking. Where did much of the sellable beef go?
• Why does heating finished cold brew not turn it into a normal hot brew?
• Why does nitro cold brew taste creamy even though there's no cream in it?
• Why does cold brew taste smooth when the same beans brewed hot taste sharp?
• Why does cold brew take hours to make when hot coffee brews in minutes?
• Why would one coffee taste much sharper than another while both have the same pH?
• Why can a 14-hour cold brew taste better than a 22-hour cold brew made with the same beans and grind?
• Why can cold-brew coffee taste different from hot coffee served over ice?
• Cold brew tastes sweeter than hot black coffee even though it has almost no sugar. What usually explains that sweet impression?
• What mainly separates craft beer from mass-market beer?
• Why isn't the coldest serving temperature best for every beer?
• Does a darker beer mean more alcohol and calories?
• What does draft (扎啤) beer actually refer to?
• What's the real difference between raw and cooked beer?
• Why should hoppy beers like IPA be drunk fresh?
• Why is an IPA so much more bitter than a lager?
• What do hops actually do in beer?
• Why is IPA not a third type of beer alongside ale and lager?
• What really makes a beer an ale or a lager?
• What are the four basic ingredients in most beer?
• Why is reganmian (hot dry noodles) mixed with sesame paste instead of served in broth?
• Why do roasted tomatoes taste sweeter than raw tomatoes?
• Why do carrots turn mushy when cooked?
• Why does beer foam?
• Why do pieces of pasta stick together while they cook?
• Why does vinegar pickle vegetables?
• Why do mushrooms turn dark when cooked?
• Why does cheese have holes?
• Why does lemon juice prevent browning?
• Why does salt preserve meat?
• Why does alcohol make you drunk?
• Why does freezing change food texture?
• Why does mint feel cool in your mouth?
• Why does baking soda make things rise?
• Why does tofu absorb flavors?
• Why do eggs turn rubbery when overcooked?
• Why can cinnamon create a burning sensation in the mouth?
• Why does olive oil solidify in fridge?
• Why does soda fizz?
• Why does ginger taste spicy hot?
• Why does cut avocado flesh turn brown?
• Why do cooked onions taste sweet?
• Why does bread get hard when stale?
• How can the enzymes in fresh pineapple contribute to a tingly mouth?
• Why does yogurt have probiotics?
• Why does searing meat in a hot pan create a brown, savory crust?
• Why does spicy food make us sweat?
• Why do bananas turn black?
• Why does freezing preserve food?
• Why does coffee keep us awake?
• Why does the body need vitamins even when food supplies enough calories?
• How does hot soup warm us?
• Why does milk make bones strong?
• Why does breakfast give us energy?
• Why do vegetables lose color when overcooked?
• Why does protein help build muscles?
• What mainly turns bread golden brown in a toaster?
• Why do we feel thirsty after salty food?
• Why does lemon juice taste sour?
• Why does fiber help digestion?
• Why does chocolate melt in your mouth?