A new ingredient to keep in your fridge, sake kasu is a fermented rice mash that’s loaded with essential amino acids and is high in glutamines (hello? the umami factor). It’s what’s left after Masa Shiroki has hand-made his sakes at Artisan SakeMaker (1339 Railspur Alley, Granville Island). At C Restaurant, chef de cuisine Quang Dang uses the creamy white paste ($3.50 for 450 grams) in what he calls “Japanese Mayo, Part 2”, blending it with honey and rice-wine vinegar to serve with salmon cakes. Shiroki himself is planning to make sake kasu gelato this summer.