Refrigeration works when you need to store clam chowder for up to three days. Freezing and canning are better storage methods for a longer duration. Some chowder ingredients do not freeze or can well. Omitting those ingredients from the recipe -- to add later when you heat the soup -- can benefit the quality of the chowder.
Herbs and spices become bitter during prolonged freezer storage. The intensity of salt changes over time during freezer storage, and it increases the rancidity of fats. Potatoes become waterlogged when they freeze and thaw, causing them to dissolve when you reheat soup. Consider reserving the seasonings and potatoes when you initially prepare your recipe.
The fat in butter can cause foods to go rancid sooner. Milk is prone to curdling after storage and reheating -- with the exception of short-term refrigeration. Initially omitting butter and milk is more than a matter of preference: You must wait to add the milk-based ingredients when you reheat the chowder to protect the safety and quality of the dish.
Package chowder in airtight, moisture-vapor resistant materials intended for food storage. Rigid plastic containers with tight-fitting lids are suitable for refrigerating or freezing chowder. Resealable plastic food-storage bags work best when you freeze chowder, because it's easier to thaw frozen soup in a bag.
You must use glass pint or half-pint canning jars if you can chowder.
Quick-cooling hot clam chowder shortens its time in the food safety "danger zone" between 40 and 140 degrees Fahrenheit, when bacteria multiply the fastest. Quick-cool the soup to 40 F if you are going to refrigerate or freeze it.
Place the pot of chowder in a sink filled with ice water, stirring the soup to expedite cooling. Replace the ice in the sink as needed.