What does "hot pack" vs "raw pack" refer to regarding canning produce? 

Hot pack and raw pack refer to the method of packing food into jars prior to canning.  There are advantages and disadvantages to each method; when both options are given, the one you choose comes down to personal preference. 

In hot packing, hot food is filled loosely into hot jars. The benefits of the hot pack method include: more air is removed in processing, which helps to retain quality, keep the food from floating, and reduce syphoning; food retains color and flavor longer; cooked food shrinks so more food can fit into the jar thus fewer jars are needed; food is more pliable and easier to pack into the jar; and a stronger vacuum seal is formed. Hot packing is generally preferred when boiling water canning.

In raw packing, uncooked food is packed tightly without crushing into hot jars (note that added liquid must be hot). Raw packing tends to be quicker and is useful for foods that loose shape when cooked. However, less food can fit in the jar; the food shrinks during processing leaving excess headspace in the jar; food (especially fruit) tends to float more; and discoloration can occur quickly (within 2-3 months). The raw pack method is generally considered more suitable for vegetables processed in a pressure canner. 

Summary tips:

• When only one option is given for the type of pack, use only that option.
• No matter the packing method, always fill product into hot jars.
• Preheat the canner to 140°F for raw pack food or 180°F for hot pack food.

There are, as is often the case, exceptions to the general rules. Processing times may be different for hot vs. raw packed food; some particular foods are best hot packed (e.g., apples, pears, peaches and pineapple); sugar-free fruit should be hot packed; and some raw-packed foods should not be tightly packed (e.g., lima beans, corn, potatoes and peas), so be sure to carefully check the recipe for specific processing recommendations.

For further information on preserving, visit the National Center for Home Food Preservation (NCHFP) or contact your local Cooperative Extension office. 

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Last updated July 2025