Etymologically
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yeast

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Pronunciation

  • /jiːst/, /jist/[1]

Etymology

It is inherited from Middle English yest, also yeest,[2][3][4] inherited from Old English ġist, also ġyst,[5][6] from Proto-Germanic *jestuz.[7][8] It is cognate with Middle Low German gest (“dregs, dirt”), Dutch gist (“yeast”), Middle High German jest (“foam”) (modern German Gischt), Old Norse jastr (“yeast”) and Swedish jäst, and related to Old High German jesan (“to ferment”), modern gären.[3][5][4] Barnhart, Hoad and Partridge trace it to Proto-Indo-European *yes- (“to foam, froth, boil”),[3][9][10] which Etymonline gives as Watkins's view;[2] the same root is seen in Ancient Greek ζεῖν (zeîn, “to boil”), the source of eczema, and in Welsh iās (“seething”).[11][9][12] Kroonen notes that the Germanic noun is identical with the Welsh one.[8]

Earliest recorded meaning

The frothy substance produced in fermentation and used in brewing and baking: Old English gist is recorded in the Leechdoms,[5] about 1000 in Barnhart's dating.[3]

Semantic evolution

In Middle English yest was also the froth or head on new or fermenting beer, a sense recorded from about 1430 to 1716.[5][3] Shakespeare used it for the foam of rough water, in The Winter's Tale.[5] As something that makes things rise or work, yeast became a figure for an active influence, like leaven, from 1769.[5] With 19th-century science the word passed to the organism itself: from 1899 it names a fungus that lives as single cells and reproduces by budding.[5] The verb, to ferment or froth, is recorded from 1819 in Merriam-Webster, but only from 1880 in the OED.[13][5] In Australian slang yeast was beer (1907), and in African-American slang the verb meant to exaggerate or boast.[14]

Timeline

  • c. 1000 – Old English gist, yeast.[3]
  • c. 1430 – yest, the froth of fermenting beer (obsolete by 1716).[5][3]
  • before 1616 – foam or froth, as of rough water, in Shakespeare.[5]
  • 1769 – figurative, a leavening influence.[5]
  • 1819 – verb, to ferment or froth.[13]
  • 1845 – compressed yeast made into a cake.[5]
  • 1899 – a single-celled fungus that reproduces by budding.[5]

Meanings

Noun

  1. Any of various single-celled fungi that reproduce by budding and can ferment sugars.[15][5][13]
  2. A preparation of such fungi, sold moist or dried, used to make dough rise and to ferment beer and wine: Add the yeast to warm water.[15][13]
  3. The yellowish froth or sediment that forms on fermenting liquids such as malt wort.[13][5]
  4. Something that stirs up or enlivens, like leaven.[5][13]
  5. Foam or froth.[5][13]

Verb

  1. To ferment or froth.[13][5][16]

Word family

  • yeastless
  • yeastlike
  • yeasty
  • baker's yeast
  • brewer's yeast
  • yeast cake
  • yeast infection
  • eczema

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  3. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  4. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
  5. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  6. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  7. ^ Orel, Vladimir (2003), A Handbook of Germanic Etymology, Leiden / Boston: Brill
  8. ^ a b Kroonen, Guus (2013), Etymological Dictionary of Proto-Germanic, Leiden Indo-European Etymological Dictionary Series 11, Leiden / Boston: Brill
  9. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  10. ^ Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
  11. ^ Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
  12. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
  13. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  14. ^ Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com
  15. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
  16. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press