The Proto-Indo-European word *h₂em-
Word *h₂em-
Meaning raw, bitter
See also Proto-Indo-European: *h₂emros ‘bitter, sour’
Synonyms *h₃em-, *h₂omós

Comments
Mallory J.P. and Adams D. (2006)

Other words that might be of interest
*kwat- ‘sour’, *sweh₂d-u- ‘sweet’, *(s)terh₁- ‘stiff’, *suhₓros ‘sour, acid’, *st(h₂)eug- ‘stiff’