Keep perch cool on the trip from the market to your house. Never let it stay unrefrigerated for long. To store perch, remove packaging, rinse fish under cold water, and pat dry with paper towels. Fish deteriorates when it sits in its own juices, so place it on a cake rack in a shallow pan filled with crushed ice. Cover with cling wrap or foil and set in the coldest part of the refrigerator. Perch will store well this way for up to two days. When well-wrapped, perch can be frozen for up to two months in a refrigerator freezer compartment and three to four months in a deep-freeze. Use lined freezer paper and wrap fish tightly from head to tail with at least two layers of paper. To thaw slowly, unwrap, place fish in a pan, cover, and leave for 24 hours in the refrigerator. To thaw more quickly, place the whole fish (enclosed in waterproof plastic) in a sink with cool running water, allowing about 30 minutes per pound (450 grams). For fastest thawing, use the defrost cycle of your microwave, allowing two to five minutes per pound (450g), with equal standing time in between zaps.