Place 6 clean 500 ml mason jars on a rack in a boiling water canner; cover jars with water and heat to a simmer (180°F/82°C). Set screw bands aside. Keep jars hot until ready to use. Preheating Bernardin® lids is not advised.

The sealing compound used for our home canning lids performs better at room temperature than it does pre-heated in simmering water (180°F). Simply wash lids in hot, soapy water, dry, and set aside until needed.

Preheating can lead to less vacuum being achieved during water bath canning, and to buckle failures during pressure canning. Wash, seed and coarsely chop tomatoes; drain off excess liquid. Measure 12 cups (3000 ml).

If using fresh corn, blanch ears in boiling water 1 minute before cutting kernels off. Measure 8 cups (2000 ml). In a large stainless steel saucepan, combine vinegar and the Fiesta Salsa Mix. Add tomatoes and corn; mix well. Over medium-high heat, bring mixture to a boil, stirring frequently.

Reduce heat and simmer stirring constantly, just until mixture is heated through. SHELF-STABLE: Ladle hot salsa into a hot 500 ml mason jar to within 1/2 inch (1 cm) of top of jar (headspace). Using nonmetallic utensil, remove air bubbles and adjust headspace, if required, by adding more salsa.

Wipe jar rim removing any food residue. Centre sealing discs on clean jar rim. Screw band down until resistance is met, then increase to fingertip tight. Return filled jar to rack in canner. Repeat for remaining salsa.

When canner is filled, ensure that all jars are covered by at least one inch (2.5 cm) of water. Cover canner and bring water to full rolling boil before starting to count processing time.

At altitudes up to 1000 ft (305 m), process - boil filled jars - 20 minutes When processing time is complete, remove canner lid, wait 5 minutes, then remove jars without tilting and place them upright on a protected work surface. Cool upright, undisturbed 24 hours; DO NOT RETIGHTEN screw bands.

After cooling check jar seals. Sealed discs curve downward and do not move when pressed. Remove screw bands; wipe and dry bands and jars. Store screw bands separately or replace loosely on jars, as desired. Label and store jars in a cool, dark place.

For best quality, use home canned foods within one year. Makes about 5 to 6 x 500 ml jars. For a thicker salsa, cook until desired consistency.

Processing: At altitudes up to 1000 ft (305 m), process - boil filled jars - 20 minutes - 15 minutes.

Altitude-adjusted processing table: At altitudes up to 1000 ft (305 m), process - boil filled jars - 20 minutes