6cupschopped green bell pepperabout 8 whole peppers
6cupsgrated green & yellow zucchiniabout 3 pounds zucchini
2-1/2cupsgrated onionabout 2 large onions
4cupsapple cider vinegardivided
2cupsgranulated sugar
2Tablespoonssea salt
2Tablespoonsmustard seed
1teaspooncelery seed
1/2teaspoonred pepper flakes
Instructions
Prepare a boiling water bath and 5 regular-mouth 1-pint/500 ml jars according to our canning basics post. Place the lids in a small saucepan, cover them with water, and simmer over very low heat.
Combine the chopped bell pepper, zucchini, and onion in a large, nonreactive pot. Stir in 2 cups/480 ml of the apple cider vinegar and bring to a simmer over medium heat. Cook until the vegetables have cooked down, about 30 minutes.
Drain the vegetables and return to the pot. Add the remaining apple cider vinegar, sugar, salt, mustard seed, celery seed, and red pepper flakes. Bring to a simmer and cook for 5 minutes.
Ladle the relish into the prepared jars, leaving 1/2 inch/12 mm of headspace. Gently tap the jars on a towel-lined countertop to help loosen any bubbles before using a wooden chopstick to dislodge any remaining bubbles. Wipe the rims, apply the lids and rings, and process in a boiling water bath for 10 minutes.
When the processing time is up, remove the canning pot from the heat and remove the lid. Let the jars sit in the pot for an additional 5-minutes. This helps to prevent the relish from reacting to the rapid temperature change and bubbling out of the jars.
Notes
Marisa's original recipe called for just green zucchini, but I love the colour contrast that a few yellow squash add to the mix.