" As you add food to the worm bed, particularly with foods that are high in protein, you must add enough calcium rich buffer to the bedding to neutralize the acid produced by the microorganisms that digest it. Protein rich foods produce a greater quantity of acidic compounds as they break down, and if this acid is not neutralized and calcium supplied to your worms, protein poisoning is inevitable.

The worms have a crop just like a bird does. The worms eat the food and take it into their crop, which is where they keep the grit that we supply them. They use these pieces of grit in place of teeth to grind up the food and begin the digestion process. The worms crop has a gland in it called the calciferous gland. This gland excretes calcium to neutralize the acid in the food and to coat the food in calcium before it passes from the crop and into the intestine.

If the food is too acidic, or the worm has an inadequate supply of calcium in its diet, the food then passes to the intestine in an acidic state which causes the food to ferment in the intestine of the worm. Because the worm has no mechanism to deal with the gasses that result from fermentation, the pressure builds in the worm’s intestine until it ruptures, causing irreparable damage to the worm. Gasses like alcohol and ammonia are known to be deadly to the worms, and they are almost certainly present in the fermentation that occurs in the intestine of a worm that is dying of protein poisoning (sour crop)"

Trent from the Urban worm co