Barm is the foam or scum formed on the top of a fermenting liquid, such as

beer Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from cer ...

wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are ...

, or feedstock for spirits or industrial

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...

distillation Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the he ...

. It is used to

leaven In cooking, a leavening agent () or raising agent, also called a leaven () or leavener, is any one of a number of substances used in doughs and batters that cause a foaming action (gas bubbles) that lightens and softens the mixture. An alte ...

bread, or set up fermentation in a new batch of liquor. Barm, as a leaven, has also been made from ground

millet Millets () are a highly varied group of small-seeded grasses, widely grown around the world as cereal crops or grains for fodder and human food. Most species generally referred to as millets belong to the tribe Paniceae, but some millets ...

combined with

must Must (from the Latin ''vinum mustum'', "young wine") is freshly crushed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of ...

out of wine-tubs and is sometimes used in English baking as a synonym for a natural leaven ( sourdough). Reinhart derived the term from his training unde
Monica Spiller
Various cultures derived from barm, usually ''

Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been o ...

'', became ancestral to most forms of

brewer's yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitu ...

and

baker's yeast Baker's yeast is the common name for the strains of yeast commonly used in baking bread and other bakery products, serving as a leavening agent which causes the bread to rise (expand and become lighter and softer) by converting the fermentable ...

currently on the market. In Ireland, barm is used in the traditional production of barmbrack, a fruited bread. Despite the name, the

barm cake A barm cake is a soft, round, flattish bread roll from North West England, traditionally leavened with barm. Chips are a popular filling, sold in most fish and chip shops in the North West of England and often called a chip barm. Another po ...

s of northern England are not necessarily made with barm.

References

{{Bread, state=collapsed Leavening agents

See also

References