Wash tomatoes under cold running water, removing any stems or leaves.
Using a small thin metal skewer, do a prick in the stem end of each tomato.
Wash the jars you are going to use in hot water.
Into each jar, put a clove of peeled garlic, a sprig of rosemary, ¼ teaspoon of pickling salt (OR salt sub), and ⅛th teaspoon Pickle Crisp, if using.
Pack tomatoes in jars, leaving 2 cm (½ inch) headspace.
Combine the vinegar and water in a large microwave-safe jug or vessel on high in microwave for 10 to 12, or until it boils. When removing from microwave, beware of possible liquid surge when first moved. Or, put in a pot on the stove, bring to a boil.
Fill jars with the hot vinegar mixture, leaving 2 cm (½ inch) headspace.
Debubble, adjust headspace.
If you are short of pickling liquid, just quickly zap some more in microwave in the same ratio as above.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process either size jar for 10 minutes; increase time as needed for your altitude.
Let stand a few weeks before opening and sampling.