rennet

noun

ren·​net ˈre-nət 

1

a

: the contents of the stomach of an unweaned animal and especially a calf

b

: the lining membrane of a stomach or one of its compartments (such as the fourth of a ruminant) used for curdling milk

also : a preparation of the stomach of animals used for this purpose

2

a

: rennin

b

: a substitute for rennin

Examples of rennet in a Sentence

Recent Examples on the Web

In keeping with their moral compass, Just Creamery only uses vegetable rennet, not animal rennet which must be harvested from calves’ stomachs. —Sean Timberlake, Sacbee.com, 13 Mar. 2026

The ingredients are cow’s milk, salt, and rennet—that’s it, just three ingredients. —Victoria Spencer, Martha Stewart, 6 Mar. 2026

Plant and microbial enzymes are employed for some other cheeses, but since all Parms are made with animal enzymes (rennet). —Karla Walsh, Better Homes & Gardens, 19 Oct. 2025

It was historically processed using rennet, an enzyme used in cheese production that separates the milk's curds from its whey.29 Like Greek yogurt, modern production of skyr involves fermenting the milk with Lactobacillus bulgaricus and Streptococcus thermophilus. —Lauren O'Connor, Ms, Health, 3 Feb. 2025

Word History

Etymology

Middle English, from Middle English *rennen to cause to coagulate, from Old English gerennan, from ge- together + *rennan to cause to run; akin to Old High German rennen to cause to run, Old English rinnan to run — more at co-, run

First Known Use

15th century, in the meaning defined at sense 1a

Rhymes for rennet

• bennet
• crenate
• jennet
• senat
• senate
• tenet

Kids Definition

rennet

noun

ren·​net ˈren-ət 

1

a

: the contents of the stomach of a young animal and especially a calf

b

: a part of the lining of the stomach that is used to curdle milk

2

: something used to curdle milk

especially : rennin

Medical Definition

rennet

noun

ren·​net ˈren-ət 

1

a

: the contents of the stomach of an unweaned animal and especially a calf

b

: the lining membrane of a stomach or one of its compartments (as the fourth of a ruminant) used for curdling milk

also : a preparation of the stomach of animals used for this purpose

2

a

: rennin

b

: a substitute for rennin