whey

American  

[hway, way] / ʰweɪ, weɪ /

noun

1. a milk serum, separating as liquid from the curd after coagulation, as in cheesemaking.

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whey British  

/ weɪ /

noun

1. the watery liquid that separates from the curd when the milk is clotted, as in making cheese

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Other Word Forms

• wheyey
  adjective
• wheylike
  adjective

Etymology

Origin of whey

First recorded before 900; Middle English whei(e), whai(e), wei, Old English hwæg, hwæig, hwǣg, hweg; cognate with Dutch, Low German wei

Explanation

Whey is what's left over after you've made cheese by straining curds. Rather than being thrown away, whey is often used to add buttery flavor or extra protein to processed foods. You may know the word whey from the nursery rhyme that begins "Little Miss Muffet sat on her tuffet eating her curds and whey..." Curds and whey are part of the cheese-making process, with whey being the slightly sour leftover liquid. Think buttermilk or thin yogurt, and you've got an idea of what whey tastes like. It's actually a great source of protein and often shows up in healthy smoothies and shakes.

Example Sentences

See Examples For:

whey

Arla also has been expanding its whey protein production.

From The Wall Street Journal ● Oct. 1, 2026

He says a 4.5kg bag of the whey protein he buys cost around £60 in 2020.

From BBC ● Sep. 23, 2026

The Canadian goods that could face new 50% duties include milk, cream and whey, as well as hockey equipment, liquor and wood products like particle board.

From MarketWatch ● Aug. 17, 2026

"With dairy products, it's got two proteins -- casein and whey -- that are bound together with fat and with nutrients mixed in," says Anderson.

From Science Daily ● Aug. 9, 2026

That night while she was washing the supper dishes and Mary and Laura were wiping them, Ma told Pa that Laura had tasted the whey and didn’t like it.

From "Little House in the Big Woods" by Laura Ingalls Wilder