Putting Food By - Janet Greene [64]
• Unnatural or unpleasant odor.
Before tasting any canned low-acid food: you must be unshakably certain that your Pressure Canner was operated correctly—pressure gauge accurate and deadweight gauge signaling properly—and that requirements for times and corrections for altitude were followed.
Unless you are sure that these safeguards were observed, a margin of protection is added by boiling the canned low-acid food hard for 15 minutes to destroy any hidden toxins (corn and greens require 20 minutes), and stirring to distribute the heat. If the food foams unduly or smells bad during boiling, destroy it completely so it cannot be eaten by people or animals.
Some Special Considerations
Salt added to vegetables in canning is merely a seasoning and therefore of course is optional. Pure canning salt is ideal, but the amounts called for are so small that the fillers, etc., in your regular table salt won’t cloud the canning liquid. However, salt substitutes should not be added to the pack before processing, lest the finished product have an unwanted aftertaste: add your salt substitute to the heated vegetable just before serving.
Starchy vegetables swell during processing, especially so if they are packed Raw, so they need double the headroom usually supplied to nonstarchy foods. Be particularly careful about shell beans of all kinds, green peas, and whole-kernel corn (hominy).
Add extra headroom at altitudes above 2000 feet/610 meters (see Correcting for Altitude in Chapter 3), because the lower atmospheric pressure allows the steam inside the jars to expand more. Also, the greater temperatures in Pressure-processing mean that the steam will expand more than in boiling not under pressure.
Some precooking water can be bitter. This of course depends on the hardness of the water to begin with, and to some extent on the growing conditions of the vegetable. However, water in which asparagus, some greens, and members of the turnip family are precooked for Hot pack can be bitter; taste the water, and if it is too strong or has a bitterness, substitute boiling water as the canning liquid.
Asparagus
Asparagus keeps more spring flavor if you freeze it; but it cans easily—whole or cut up.
GENERAL HANDLING
Only Pressure Canning for asparagus: it has even less acid than string beans. Hot pack preferred. Use jars or plain cans.
Wash; remove large scales that may have sand behind them; break off tough ends; wash again. If you’re canning it whole, sort spears for length and thickness, because you’ll pack them upright; otherwise cut spears in 1-inch pieces.
PREFERRED: HOT PACK
Whole spears—stand upright in a blanching or steaming basket and dunk it for 3 minutes in boiling water up to but not covering the tips; drain and pack upright (tight but not crammed). Cut-up pears—cover clean 1-inch pieces with boiling water for 2 to 3 minutes; drain.
In jars. Loosely fill with hot asparagus, whole spears upright, leaving 1 inch of headroom. (Optional: add ½ teaspoon salt to pints, 1 teaspoon to quarts.) Add boiling blanching liquid (if it’s free of grit) or boiling water, leaving 1 inch of headroom; remove trapped air with slender plastic spatula. Adjust lids. Pressure-process at 10 psig (240 F/116 C)—pints for 30 minutes; quarts for 40 minutes. Remove jars; complete seals if using bailed jars.
• Adjustment for my altitude_________________.
In plain cans. Pack as for jars, leaving only ¼ inch of headroom; add ½ teaspoon salt to No. 303 cans, 1 teaspoon to No. 401 (optional). Fill to top with boiling water. Exhaust to 190 F/83 C (about 7 minutes); seal and pressure process at 10 psig (240 F/116 C)—No. 303 cans for 25 minutes, and No. 401 for 30.
• Adjustment for my altitude_________________.
Beans, “Butter”
See Beans, Fresh Lima.
Beans—Green/Italian/Snap/String/Wax
Perhaps next to tomatoes, these beans are the most popular vegetable canned by North American householders. They also are established as being the single most likely source of botulism poisoning among home-canned foods.
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