Prep the zucchini. If you are shredding, no need to peel. If you are cubbing, I like to peel before cutting it up.
Clean and sterilize your jars. This is a hot recipe, the jars need to be hot when packing the ingredients.
Get your water bath canner going on high. You want the water to be boiling before you set the jars inside.
In a large pot, combine the pineapple juice, sugar and lemon juice. Bring it to a simmer and add the zucchini. Simmer for 20 mins.
With a slotted spoon, add the zucchini to the jars, no liquid.
Then add the liquid on top. Leave 1/2 an inch of headspace.
Use a butter knife or chop stick to get the bubbles out of the jar. Do so by placing your object against the Side of the jar in up and down motions. You'll see the bubbles pop.
Clean off the tops of the jars with a towel and a dab of vinegar. You do not want any sticky juice on that rim.
Add lids and rings to the jars, fingertip tight
Water bath can for 15 min (for pints)
Carefully remove jars, try not to tilt them. Set jars on your counter for 24 hours. Leave them be, do not touch!
After 24 hours, remove the rings and check the seal.