Putting Food By - Janet Greene [82]
Water used in cleaning seafood and preparing them for packing must be of drinking quality—whether it’s the running water for washing them (which is always done under a tap, or with a spray or hose), or the water in a brine or antidiscoloration solution, or the canning liquid that goes in the jar.
Reason: it’s easy to introduce dangerous bacteria, including C. botulinum itself, into the flesh by using polluted or contaminated water at any stage. Do not rinse fish in stream or lake water. Do not precook shellfish in seawater. If your household drinking water contains a lot of minerals, use bottled water at least for the canning liquid (iron, especially, reacts with the sulfur in the meat of shellfish and causes the product to darken).
All seafood to be canned must be as fresh as is possible. Fish must be gutted as they’re caught, and refrigerated or packed in ice immediately, to be kept cold until they are precooked or packed. Head shrimp immediately as they come from the water, refrigerate, or hold on ice. Keep lobsters, crabs, and clams alive and cool until you prepare them for packing.
Reason: it takes only a couple of hours at room temperature to make dead seafood unfit to can; and spoilage is hastened if intestines and body wastes are not removed.
The flesh of all dressed and cleaned fish and shelled shrimp is given a preliminary brining; lobsters and crabs are precooked in brine and well rinsed before shelling. (The picked meat of lobsters, crabs, and clams is given a further anti-darkening treatment in a mild acid “blanch” before packing.)
Reason: brining draws diffused blood from the tissues, and reduces the chance that white curds of coagulated protein will occur in the processed jars. (Brines must be made up just before use, and should be used only once.)
The day after the seafood has been canned, store the jars in a cool, dry, dark place.
Reason: storage that lets the jars freeze can also break the seals; storage over 50 F/10 C courts spoilage; damp storage rusts metal closures and endangers the seals. During the 24 hours between processing and storing, check all seals, clean, and label the jars.
Canned Seafood Troubles
Do NOT reprocess jars of seafood found to have poor seals during the 24 hours of grace between canning and storage. And even if the contents are decanted into fresh containers and done over from scratch, the result is likely to be unsatisfactory (all the more reason for taking care in the first place).
After jars are stored you must be super-critical in examining them for external signs of spoilage: broken seal (flat lid no longer concave)—seepage around the closure—gassiness in the contents—cloudy, yeasty liquid or sediment at the bottom of the jar—contents an unnatural color or texture. If any of these signs are present, destroy the food so it cannot be eaten by people or animals, sterilize the container and closure by boiling, and discard the sterilized closure.
Even when the seal seems good and none of the trouble symptoms just listed is apparent, these are the signs of spoilage when you open a jar of seafood: pressure inside the container (instead of a vacuum), or spurting contents—fermentation—sour, cheesy odor—soft, mushy contents. If any of these signs is present, destroy the food and sterilize the container and closure, as above.
Before tasting home-canned seafood: you must be unshakably certain that your Pressure Canner was operated correctly—pressure gauge accurate and deadweight/weighted gauge signaling properly—and that requirements for times and corrections for altitude were followed.
Boil the food hard for 20 minutes to destroy possible hidden toxins, stirring to distribute the heat and adding water if necessary. If the