What does souring mean?
Souring describes the process by which something becomes sour, most often because acids develop or are introduced. The word commonly describes food changing taste or texture: milk souring in warm conditions, cream ripening under bacterial cultures, or wine developing acidity. Souring does not always indicate decay, because controlled souring is essential in the production of foods such as yogurt, cheese, and some preserved vegetables. It can also be used attributively, as in “souring agent,” for a substance that promotes acidity, and less commonly as a noun for that agent. In general descriptions, the word emphasizes a change toward an acidic or fermented state rather than the sharper, sometimes unpleasant taste called sourness. As a present participle, it can describe either an ongoing natural process or the deliberate production of that result.
To become or turn sour.
"The sauce began souring as it cooled."
Normally used in the present-participle form “is souring” or as a gerund, especially of food or another substance changing through acidity or fermentation.
Causing or undergoing the process of becoming sour.
"The cook added a souring agent to the mixture."
Chiefly attributive and common in food preparation, preservation, and food science.
The process of becoming sour or a substance that causes it.
"Controlled souring gives the yogurt its characteristic flavor and texture."
This nominal use is less common outside technical and food-processing contexts.
Not every change in food's taste is spoilage: milk souring through beneficial lactic acid bacteria is how yogurt and many traditional cheeses are made.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does souring come from?
The form derives from the English adjective and verb “sour,” which comes from Middle English “sour” and Old English “sūr.” The Old English word belonged to the Germanic family and is related cognately to words such as German “sauer” and Dutch “zuur.” “Souring” became the modern present participle and gerund form through the ordinary English process of adding “-ing.”
Related word forms
How souring is actually used
The form is most naturally read as the present participle of “sour.” As an adjective, it commonly occurs in combinations such as “souring agent,” while the nominal sense is mainly found in technical or food-processing contexts.
Easily confused with souring
Souring means becoming or causing something to become sour, whereas soring means causing pain, especially in a muscle or joint.