Rinse several times and leave to drain for 8 to 12 hours. Wash and drain again until tiny shoots appear. Soy beans need double soaking. Legumes have developed many toxic chemicals to protect their nascent seeds from nematodes, micro organisms etc. This is called allopathy.
All seeds contain phytates in their outer seed coats.
When seeds are soaked and germinated, enzymes are created which will split and neutralize phytates. In addition to phytates, legumes contain other harmful ingredients that can be eliminated by sprouting and germinating and then heating. Raw soy beans have a substance that stimulates goitre, and also a trypsin inhibitor. Trypsin is an enzyme necessary in the digestion of protein. Lima beans have a toxicant, glycocide, which yields hydrocianic acid.