Putting Food By - Janet Greene [20]
Vinegar. Vinegar is acetic acid, and all vinegars corrode metal, so when you use them in larger-than-spoonful amounts—in making pickles and relishes—make sure your kettle or holding vessel is enameled, stainless steel, ceramic, or glass. Acetic acid reacts badly with iron, copper and brass, and with galvanized metal (which we don’t like to use with any food because of the possibility of contamination from cadmium in connection with the zinc used in galvanizing; and zinc itself can be toxic). Vinegared foods corrode aluminum.
The cider vinegar bought in supermarkets usually runs about 5 to 6 percent acid. Its pronounced flavor can be an asset with spicy condiments and pickles, but a drawback elsewhere. Its color is unimportant for dark relishes, but hurts the looks of light-colored pickles. Because of its flavor and color, it should not be used with fruits or bland foods. The minerals present in any vinegar that has not been distilled can react with compounds in the water or the food’s tissues to produce undesirable color changes. All of which boils down to: do not use cider (or malt) vinegar to reduce the pH rating of the specific fruits and vegetables cited above—unless it’s a last resort, and unless you’re prepared for changes in color and flavor.
Use white (distilled) vinegar for decreasing pH rating of foods mentioned above if you don’t have citric acid or lemon juice—but double the measure used for lemon juice. Reason: the acetic acid in vinegar is more volatile than the citric acid in lemon juice.
Avoid using “raw” or “country” vinegar for the purposes cited here—it’s likely to have sediment, and its flavor is pronounced. And save wine and special herbed vinegars for dressing salads or vegetable dishes.
Firming Agents
Having raw materials in prime condition and perfectly fresh, plus handling them promptly and carefully add up to the best natural means of ensuring that your put-by foods are firm and appetizing.
Salt. In canning, freezing, or curing fish for smoking, a short stay in a mild brine that is kept ice-cold will not only draw diffused blood from the tissues but also will firm the flesh and result in a better product.
In drying fish (Chapter 21), a larger concentration of salt is generally used to draw moisture from the tissues and make the flesh firm.
In pickles, the original “short-brine” firms the vegetables. Be sure to shave off the vestigial remains of the blossoms of pickling cucumbers, because this is where enzymes concentrate; and unless enzymatic action is halted, such foods will soften.
Cold. Refrigerating meats, poultry, and produce, and holding seafood on ice until they are prepared for processing, will do much to ensure food with good, firm texture.
Calcium hydroxide is also called slaked lime (slaked, because liquid has been added to it, whereby it became heated, and the residue remains) and pickling lime. It is sold in some drugstores and in online stores as a firming agent for pickles. Calcium hydroxide is preferred by some nutritionists over alum and calcium chloride (both below), but PFB takes a dim view because it can zap pH in foods.
Alum is any of several allied compounds, and was called for in old cookery books to make pickles crisp—usually watermelon or cucumber chips. If a fairly large amount is eaten, it often produces nausea and even severe gastro-intestinal trouble. Alum is not an ingredient in any of the pickle recipes in this book.
Calcium chloride, of course, food-grade. Some people find this more acceptable than alum, but we do not include it in any pickle recipe or canning instruction in this book. It is an ingredient often used by commercial canners, especially in tomatoes. If you feel impelled to use it, get it from a drugstore or internet source