scrap, waste
粕 centers on the leftover, useless residue after something valuable has been extracted: scraps, dregs, or waste material.
粕 combines 米 (rice) with 白 (white), suggesting the white, leftover rice dregs after brewing or pressing. The exact historical development is uncertain, but the component combination fits the meaning of waste or scrap from grain processing.
Rice 米 that has turned white 白 and empty after all the good stuff is taken out: that's the scrap, the waste, the leftover dregs.
For ハク, imagine a hack job of processing rice, leaving only white waste behind: hack -> ハク, and the scrap is all that remains.
thick amazake; thick sweet sake
oil cake; scrap cake
rapeseed meal; rapeseed lees
shavings; filings
miso lees; miso strainings; miso dregs
soybean cake
shōchū made from sake lees
shōchū made from sake lees
fish or vegetables pickled in sake lees
sake lees
fish fertilizer; fertilizer made from fish scraps
bean cake; soybean (oil) meal
soy sauce lees; soy sauce cake
residue left after making starch syrup
fish meal
dried and pressed boiled herring (used as fertilizer)
sake lees with black or brown specks (from oxidation enzymes produced by the yeast)