whey

American  

[hwey, wey] / ʰweɪ, weɪ /

noun

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

---

whey British  

/ weɪ /

noun

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

---

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

I enrolled in a cheesemongering certification course through the UK-based Academy of Cheese and spent months with notecards on curds and whey, then more months learning how to taste with intention.

From Salon • Mar. 25, 2026

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

The brand is best known for making specialty whey butter, which uses the cream that is separated from whey to produce a “mild, nutty, cheesy and richer, fuller flavor” butter, per its official website.

From Salon • Aug. 16, 2025

Once regarded as a by-product in cheese-making, whey protein has become increasingly popular for use in smoothies, food and for people using injectable weight loss medications to prevent muscle wastage.

From BBC • Aug. 6, 2025

The first day Ma made cheese, Laura tasted the whey.

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