Lupin or lupini beans are the yellow legume seeds of the genus Lupinus. The bitter variety of the beans are high in alkaloids and are extremely bitter unless rinsed methodically. Low alkaloid cultivars called sweet lupins have been bred, and are increasingly planted. Lupin beans are growing in use as a plant-based protein source around the world. Turmus K Beej Lupin Beans Benefits Lupini beans are commonly sold in a brine in jars (like olives and pickles). They can be eaten by making a small tear in the skin with one’s teeth and “popping” the seed directly into one’s mouth, but can also be eaten with the skin on.