Extension of *gʷʰer- "warm". Warmth applied to fermentation of bread and beer.
bʰeHg-d-“to bake, to harden by heat”bʰer-s-“top, point, bristling tip”bʰerw-“to boil, brew, ferment”bʰerw-mn̥“that which ferments, yeast”bʰerw-mn̥-₂“boiling, fermenting mass”bʰlendʰ-mn̥“a mixing, a blending together”bʰrewh₁-“to brew, to boil”bʰruHg-“to enjoy, to use”