Yuca, which is also called cassava, is available fresh and frozen in Hispanic markets. Check that there are no hairline cracks in the bark-like brown skin when purchasing fresh yuca. Yuca should be kept in a cool place outside the refrigerator. If you use some of it, peel the rest and store in the refrigerator, in water, to cover for 1 day, or freeze, well wrapped, for up to 3 months. To peel, first scrub and then cut it in half crosswise. Quarter each section lengthwise, then peel away the outside skin with a sharp knife. Rinse before cooking.