Spinach and other greens should not be blanched in hot water. They must be blanched in steam. To do this place them in a colander and set this into a vessel which has a tightly fitting cover. In this vessel there should be an inch or two of water, but the water must not be allowed to touch the greens. Another method is to suspend the greens in the closed vessel above an inch or two of water. This may be done in a wire basket or in cheesecloth. Allow the water to boil in the closed vessel from fifteen to twenty minutes.
When the blanching is complete remove the vegetables or fruits from the boiling water or steam and plunge them once or twice into cold water. Do not allow them to stand in the cold water. This latter process is the Cold Dip. It hardens the pulp and sets the coloring matter in the product.
Steps in the Single Period Cold-Pack Method
In canning by the Single Period Cold-Pack method it is important that careful attention be given to each detail. Do not undertake canning until you have familiarized yourself with the various steps, which are as follows:
1. Vegetables should be canned as soon as possible after being picked; the same day is best. Early morning is the best time for gathering them. Fruits should be as fresh as possible.
2. Before starting work have on the stove the boiler or other holder in which the sterilizing is to be done, a pan of boiling water for use in blanching and a kettle of boiling water for use in filling jars of vegetables; or, if canning fruits, the syrup to be used in filling the jars. Arrange on this working table all necessary equipment, including instructions.
3. Test jars and tops. All jars, rubbers and tops should be clean and hot.
4. Wash and grade product according to size and ripeness. (Cauliflower should be soaked 1 hour in salted water, to remove insects if any are present. Put berries into a colander and wash, by allowing cold water to flow over them, to prevent bruising.)
5. Prepare vegetable or fruit. Remove all but an inch of the tops from beets, parsnips and carrots and the strings from green beans. Pare squash, remove seeds and cut in small pieces. Large vegetables should be cut into pieces to make close pack possible. The pits should be removed from cherries, peaches and apricots.