The bitter taste of lupin alkaloids can be sensorially detected in water within ppm-range. The strength of the taste diminishes as follows: sparteine, D-Lupanin-perchlorate, lupinine, isolupinine and hydroxylupanine. The swelling capacity of lupin seeds presents different characteristics according to the species. The swelling rapidity is in L. albus somehow inferior to that of L. mutabilis. The absorption of water decreases in hot water, and the swelling rapidity increases. For domestic debittering it is recommended to cook whole lupin seeds during half an hour and to debitter them for 3 days in flowing water. The isoelectric point of the protein of L. mutabilis lies between pH 4 and 4.5.