Pepperoncini peppers, also known as sweet Italian peppers, Tuscan peppers, or golden Greek peppers, are sweet, mild peppers with a fairly low level of heat. Although these peppers are usually harvested when they are 5-8 cm (2 to 3 inches) long and bright green in colour, the peppers grow larger and sweeter and turn deep red. Pepperoncini peppers are usually sold pickled, but pickling your own pepperoncini peppers at home is easy and fun.
Sterilise eight 1-pint or 1/2-pint glass canning jars. (Most hot water bath canners can accommodate 8 jars.) Place the jars in a large kettle filled with boiling water. You can also sterilise the jars in your dishwasher on the "hot" setting. Keep the jars hot until you're ready to fill them with peppers. Wash the lids and rings, then keep the lids and rings hot in a saucepan filled with simmering water.
Wash the peppers thoroughly. Place the peppers on a cutting board and use a paring knife to make 2 to 3 small slashes in each pepper. The peppers can also be pricked with a fork. Slitting the pepperoncini will allow the peppers to fill with vinegar. Otherwise, the peppers may float.
Make the pickling brine for the pepperoncini peppers. Combine three parts distilled vinegar with one part water, then simmer the brine for 10 minutes. Make enough brine to fill your jars. (For example, if you have eight 1/2-pint jars, you will need 4 pints of brine.) Pack the peppers into the hot jars, then cover the peppers with the hot pickling brine.
Wipe the top of the jars with a clean, damp cloth, then attach the lids and rings. Place the filled jars in a hot water bath canner. As soon as the water returns to a full boil, set your timer for 15 minutes.
Remove the jars from the hot water as soon as the timer rings. Set the jars on a wooden board or a thick layer of towels and allow the jars to cool completely before storing.
If you live in a area with an altitude of less than 300m (1,000 feet), decrease the hot water bath processing time to 10 minutes. In altitudes above 1,500m (5,000 feet), increase the processing time to 20 minutes. For more flavour, add a few small onion chunks or garlic cloves to each jar of peppers.