Definition: Methods used to remove already formed contaminants from a stream of air, water, waste, product or similar. These techniques are called 'end-of-pipe' as they are normally implemented as a last stage of a process before the stream is disposed of or delivered. Source: GreenFacts.
The best canning tomatoes will be the varieties that Heinz and Campbell came out with over the last 70 odd years. Heinz 1350 and Heinz 1439 are two that come to mind and are readily available on the net. Both are determinate and heavy producers which helps a bit for processing.nd best to a fresh garden grown tomato is a well done home canned one---somewhere around last place comes the wintertime fakes offered at the local superstore. A few variables to consider: 1  Firmness after processing. 2  Taste after processing. 3  Size compared to neck size of the canning jar.
Why do we add lemon juice or citric acid when canning tomatoes? Answer - Tomatoes were once considered an acid food that could be safely canned in a boiling-water canner. However, because of the potential for botulism when some newer, less acidic tomato varieties are canned, certain precautions must now be taken. Add 1 tablespoon bottled lemon juice to pints and 2 tablespoons bottled lemon juice to quarts of tomatoes. Or add one-fourth teaspoon crystalline citric acid to pints and one-half teaspoon crystalline citric acid to quarts of tomatoes. Acid can be added directly to jars before filling. Four tablespoons of 5 percent acidity vinegar per quart may be used instead of lemon juice or citric acid, however, it may cause undesirable flavor changes. Add sugar to offset acid taste if desired.