Miso paste is a staple Japanese cooking ingredient made by fermenting soy beans, and occasionally other ingredients such as barley or rice, with koji (an edible fungus that grows on rice and is also known as 'rice malt' or 'rice mould'). Miso can vary in flavour and texture from sweet and smooth to savoury and course, depending on the ingredients used and fermentation time. If you are looking to explore the wide world of miso, Japan Centre's Miso section is a good place to start.