In North Germanic languages such as Swedish, the word for cheese is ost, or something similar. Since I learnt this, I’ve been wondering where it comes from, so I decided to investige.
Ost comes from the Old Norse ostr (cheese), from the Proto-Germanic *justaz (cheese), from the Proto-Indo-European *yewH-s- (sap, juice, broth), from *yewH- (to blend, mix (food), knead).
From the same root we get the Latin word iūs (gravy, broth, soup, sauce, juice), from which we get the English juice, the French jus (juice), and the Welsh uwd [ɨ̞u̯d / ɪu̯d] (porridge, oatmeal).
Words for cheese in Finnic and Samic languages are also related: juusto in Finnish, juust in Estonian, and vuostá in Northern Sami.
I wonder if yeast is related?
Yeast comes from the Middle English yest, yeest, gest, gist, from the Old English ġist, ġyst, from the Proto-Germanic *jestuz (fermentation, yeast), from *jesaną (to ferment) [source].