Zucchini relish

Ingredients:

• 1.3 - 1.5 kg zucchini or yellow squash, cut into 0.5 cm thick circles.
• 1.8 - 2 kg onions, thinly sliced
• 0.5 cup coarse salt
• 0.5 cups of sugar
• 2 cups white distilled vinegar
• 2 cups apple cider vinegar
• 2 tsp. mustard seeds
• 1 and 3/4 teaspoons celery seeds
• 1 and 3/4 teaspoons ground turmeric
• 1 packet of dry pectin

Preparation:

1. Prepare the vegetablesLayer the zucchini and onion in a large, non-reactive bowl, sprinkling each layer with coarse salt. Let sit in the sink for 3 hours. Drain the liquid, place it in a large colander, and rinse thoroughly under cold water. Place the bowl on top of the vegetables and add a couple of cans or whatever you have on hand to weigh the bowl down and squeeze out as much water as possible from the zucchini.
2. Prepare jars and lidsWash all jars and lids thoroughly with soapy water and rinse well. Fill a saucepan (or pressure canner) with water to a depth of at least 2 cm (0.8 in) above the jars and bring to a boil. Use tongs to carefully lower the jars, tilting them to fill them with hot water. Pour hot, but not boiling, water into a small saucepan; place the lids in the water. Add another kettle of water to the heat.
3. Prepare the brineIn a large non-reactive saucepan or cauldron, combine the sugar, vinegar, mustard seeds, celery seeds, and turmeric and bring to a boil. Add the zucchini and onion. Stir gently until the mixture comes to a boil. Remove from heat and let cool.
4. Make a relishTransfer the pickled vegetables in batches to a food processor and puree until smooth. Return the relish to the pan and bring to a boil. Add the pectin, stir until completely dissolved, then bring back to a boil and cook for 1 minute.
5. Fill and close the jarsUsing tongs, remove the jars from the pot, carefully pouring the water back into the pot. Place them next to the pot with the relish. Increase the heat under the canner to high. Using a ladle, pour the relish into the jars through the funnel, leaving 1 cm of space above the rim. Run a clean chopstick inside each jar to release any air bubbles. Wipe the rims of the jars with a damp paper towel. Place the lids on and screw them on tightly.
6. Preserve the jarsUsing jar tongs, carefully transfer the jars to the pressure canner so they stand upright. Once all the jars are in the pan, they should be covered with at least 2 cm of water; if not, add more from the kettle. Bring the water to a full boil and simmer for 10 minutes.
7. Remove and cool.Using jar tongs, carefully remove the jars from the pressure canner and place them upright on a kitchen towel or wire rack. Do not place hot jars directly on a cool surface. Let cool without moving for at least 12 hours. If any jars are not sealed tightly, re-can them as described above or refrigerate them and use immediately.
   
   
   Storage
   
   Label the lid or jar with the canning date. Remove the rings and store the jars in a cool, dark place for up to 12 months. Refrigerate opened jars..