It can be found in most grocery stores in refrigerated dairy and fresh produce cases. The aseptic packs don't need refrigeration until they're opened. If you purchase the water-packed type, drain water from the plastic tub daily, cover with fresh cold water and return to the refrigerator. This will keep the product fresh for up to one week. Always check the expiration date.
Fresh tofu has a mild odor, if it smells sour, return it.
Varieties of tofu include extra firm, firm, soft and silken. The soft and silken types work well in recipes calling for blending. The firm and extra firm are best for slicing, marinating, grilling and stir-frying. Steam in a basket over boiling water for 15 minutes. Place the tempeh and sliced onion in a deep dish and pour the barbecue sauce over it.