Putting Food By - Janet Greene [168]
Build your regular hardwood fire; after it is burning well, smother it with fine hardwood chips or sawdust to produce a very dense smoke with little heat—the temperature inside the smoke chamber ideally should never exceed 70 F/21 C in order to inhibit growth of bacteria in this highly perishable food. Tend the fire night and day: smoking fish is a continuous process.
After the end of 4 full days of smoking, sample a piece of fish to see if its color, flavor, and texture are what you want. If not, smoke it 24 hours more, and test again. When it is smoked to your satisfaction, air-dry the pieces in a cool place for several hours. Then package the fillets individually in plastic wrap and store at 32–40 F/Zero–4 C for up to 3 months.
Freezing will cause salt in the tissue to deposit on the surface of the fillets. We do not recommend that smoked fish be canned at home.
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Drying
The purpose of drying is to take out enough water from the material so that spoilage organisms are not able to grow and multiply during storage: to be remembered as one of the six factors in preservation. The amount of remaining moisture that is tolerable for safety varies according to whether the food is high-acid or low-acid raw material, or whether it has been treated with a high concentration of salt—and, to some degree, with the type of storage.
Although the terms “drying,” “dehydrating,” and “evaporating” are often used casually as meaning the same thing, the USDA Research Service’s fine multivolume Agriculture Handbook No. 8, which tells the composition of raw, processed, and prepared foods of all sorts, lists as dehydrated those foods containing only 2.5 to 4 percent water—the other 96 + percent having been removed by highly sophisticated processes that we can’t hope to equal at home. It lists as dried those foods still containing roughly 10 to 20 percent water (the amount depending on whether they’re vegetables or fruits). We can take out all but this much moisture with the equipment and methods described in this section—and we’ll call it drying.
General Procedures in Drying
Dry only food that is in prime condition and perfectly fresh, just as you choose it for any method of putting by; and handle it quickly.
Be scrupulously clean at every step. A number of the micro-organisms that cause food poisoning, ranging from the Salmonellae to C. botulinum and including molds and fungi, contaminate the food because they are in the soil or on the surfaces of our workplaces or even in the air around us.
The procedures described hereafter do not undertake to sterilize food. However, a moisture content of less than 35 percent can greatly slow the growth of micro-organisms.
Before drying starts and after the food is pared/cored/sliced or whatever, much of it will be given some sort of treatment to preserve color, prevent decomposition, and safeguard nutrients (in general, though, drying is hard on some of the vitamins). Depending on the type of food, these treatments are: for fruit, coating with an anti-oxidant or sulfuring; for vegetables, blanching in boiling water or steam to stop enzymatic action; and, in the case of meat or fish, salting.
Throughout the drying process the food must be protected from air-borne spoilers and from vermin—and simply from poor handling. Regardless of where it is being dried, it will lie on only food-grade materials and it will be shielded from insects. After it tests dry, any unevenness in moisture content will be equalized by conditioning; insect eggs, if there are any, will be destroyed by pasteurizing the food; it will be stored in food-grade containers, safe from infestations or dampness or temperatures too warm.
Equipment for Drying
If you plan on drying a great deal of food, you should invest in a dehydrator, which is essentially an enclosed box with four to ten mesh trays, a heating element, and a fan. There are two principal types. In one, the heating element and fan are located at the side of the unit, creating a horizontal airflow,