Grains

Only the heartiest whole grains can withstand eight hours of slow cooking without breaking down completely: pot (hull-less but not pearled) barley (look for this in the bulk bins at the supermarket or in natural-foods stores), hard red or white wheat berries, rye berries, and spelt, for example. If you want a dish with very distinct, firm grains, and your recipe is vegetarian, replace some of the water in the recipe with ice to slightly delay the start of cooking (see for an example). Quicker-cooking grains, like millet and quinoa and white and brown rices, will become mushy over eight hours—good for thickening purposes or for porridges or congee, but not if you want individual grains to be apparent in the finished dish. Cook delicate grains separately and fold them in at the end or serve them on the side.