One of Clemson’s Canning Coaches was asked about "dump" recipes for the slow cooker. She asked me, “Is this a good idea? The idea is to prepare the recipe, package it in gallon freezer bags and then put it in the freezer. It involves putting raw vegetables in the freezer without blanching them. And why do we have to blanch vegetables before freezing them?”
Answer: A “dump” recipe is a new term for me. But after checking out several “dump” recipes on-line, I personally like the idea of preparing one-dish meals in advance for my crock pot or slow cooker. My slow cooker gets lots of use in the winter and I am generally in favor of anything that will speed up meal preparation.
As long as ingredients are handled properly during preparation, no special safety issues are associated with freezing. Generally what goes into the freezer is what comes out of the freezer. In other words, freezing cannot be counted on to kill bacteria but bacteria (including Clostridium botulinum) do not grow at freezing temperatures.
I saw several recipes for dump chicken that used canned fruit, canned vegetables, or prepared sauces (http://freezerfriendly.blogspot.com/2008/07/dump-recipes.html). For those recipes blanching vegetables would not be an issue. If commercially frozen vegetables are used, they have already been blanched. If home grown vegetables are used, they should be blanched for best quality. The longer unblanched vegetables are stored frozen, the more likely they will taste “off,” “green” or “grassy.”
Why blanching? Harvested fresh vegetables continue to undergo chemical changes associated with ripening that eventually will cause spoilage and deterioration. They should be frozen as soon after harvest as possible and at their peak degree of ripeness. In unblanched vegetables, those changes will continue (albeit more slowly) at freezer temperatures. Enzymes naturally present in vegetables that cause ripening, softening and other changes must be inactivated (by blanching) to prevent nutrient loss, color loss and flavor changes. In most cases blanching is absolutely essential for producing top-quality frozen vegetables. Blanching also helps destroy microorganisms on the surface of vegetables, brightens color, helps retard loss of vitamins and helps make some vegetables, such as broccoli and spinach, more compact. It is important to follow the time recommended for each vegetable carefully. Under-blanching stimulates enzyme activity and is worse than no blanching. Over-blanching causes loss of flavor, color, vitamins and minerals. Rapid cooling after blanching is critical to retaining vegetable quality.
The Container: Flexible freezer bags are suitable for freezing dry-packed goods, liquid foods and foods with irregular shapes. Containers larger than one-half gallon are not recommended for freezing fruits and vegetables because they freeze too slowly to produce a quality product. If freezing dump recipes in gallon bags is desired, they need to be as flat as possible to freeze reasonably quickly. Eliminating as much air as possible from freezer packages is critical because air interacting with frozen food can cause browning and rancidity.
Pointers for freezing:
Seasonings and Spices: One final point should be considered for best “dump” recipe quality. When using seasonings and spices, season lightly before freezing, and add additional seasonings when reheating or serving. Pepper, cloves, garlic, celery seasonings, green pepper, imitation vanilla and some herbs tend to get stronger and bitter. Onion, paprika and curry change flavor during freezing. Salt loses flavor and has the tendency to increase rancidity of any item containing fat.
Final Note: For safety, “dump” recipes should be thoroughly thawed in the refrigerator or in cold water, before adding them to a slow cooker.