Blanching and Parcooking

Partial cooking may be done by any moist-heat or dry-heat method. Those commonly used are simmering or boiling (parboiling), steaming, and deep-frying (especially for potatoes). The term blanching may mean any of these methods, but it usually implies very brief cooking.

There are four main reasons for blanching or parcooking:

1. To increase holding quality.

   Heating helps preserve foods by:

   • Destroying bacteria that cause spoilage.
   • Destroying enzymes that discolor foods (as when potatoes turn brown) and cause them to deteriorate.

2. To save time.

   It takes less time to finish parboiled vegetables for service than it does to finish raw vegetables. Large batches of foods may be blanched and chilled, and individual portions then finished to order.

   Items, such as roast duck, that take too long to cook completely to order are often roasted half to three-quarters done and then finished as the orders are received.

3. To remove undesirable flavors.

   Some variety meats and certain strong-flavored vegetables, such as rutabaga, are sometimes blanched to make them milder and more acceptable to the customer.

4. To enable the product to be processed further.

   For example, vegetables and fruits such as tomatoes and peaches, as well as some nuts, are blanched to loosen the skins for peeling.

   Sweetbreads are blanched so they are firm enough for slicing and breading or other kinds of handling.