whey

American  

[hwey, wey] / 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

Executive producers Jon Erwin and Jon Gunn discuss bringing the biblical character to life in their series and whey they cast Michael Iskander in the lead role.

From Los Angeles Times • Mar. 20, 2026

Eventually they'll produce beta-lactoglobulin, a protein found in whey.

From BBC • Oct. 6, 2025

The health and beauty firm behind the Myprotein brand has said its profits will fall by £13m because of the high price of key ingredient whey.

From BBC • Aug. 6, 2025

Our research shows there's no silver bullet to solve whey waste.

From Salon • Oct. 22, 2024

When no more whey dripped from the cloth, Ma emptied the curd into a big pan and salted it, turning and mixing it well.

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