Canning zucchini isn’t as straightforward as you might think. Unlike most vegetables, plain zucchini isn’t approved for home canning (pressure canning or otherwise), and there are no tested recipes for canning plain zucchini. That said, there are a number of tested zucchini canning recipes that will work for everything from zucchini pickles, to relish and jam.
Most zucchini canning recipes are for water bath canning, since they use other sources of acidity to bring the pH to a safe level (lemon juice, vinegar, or pineapple juice). If you do happen to have a pressure canner, there’s even a tested way to can zucchini in tomato sauce/juice for savory recipes (just not plain zucchini canned in water).
Canning is one of my favorite ways to preserve produce from the garden, especially highly perishable summer produce. Zucchini seems like the perfect candidate since as a tender-skinned summer squash it just won’t keep in the root cellar like the thick-skinned winter squash from later in the season.
The bad news though? You can’t just can plain zucchini.
But why not?
Squashes, in general, are tricky to can at home, since they’re low acid vegetables they must be pressure canned. The problem is, they tend to fall apart into mush in the pressure canner, which creates issues for even heat penetration through the jar.
You cannot can squash puree, and if you’re canning pumpkin, it must be canned as pumpkin cubes in water for home canners. Zucchini cubes don’t exactly hold up to pressure canning, and just turn into puree on their own anyway during extended periods to heat and pressure in the canning process.
But just because you can’t can plain zucchini, doesn’t mean there aren’t zucchini canning recipes!
It’s perfectly fine to make acidified recipes like zucchini pickles, zucchini relish, and even zucchini marmalade for water bath canning. The added acidity in these tested recipes means they’re safe for water bath canning.
There are even a few creative zucchini canning recipes, like zucchini canned in pineapple juice that creates “zucchini pineapple” that tastes more or less exactly like home-canned pineapple.
Most of these recipes are for pickled condiments or sweet preserves, but if you’re determined to find a savory zucchini canning recipe, fear not! There is one approved pressure canning recipe for canning zucchini in tomato juice.
The tomato juice adds acidity (but not enough to make it a water bath canning recipe) and keeps the zucchini from falling apart during the canning process. That means you can use it for savory winter soups and sauces, incorporating it along with other vegetables and seasonings.
The idea behind making zucchini pickles isn’t all that different from plain old cucumber pickles, and they’re pretty similar sliced in jars.
Personally, I actually prefer the texture of zucchini pickles, as I think they stay crisper. Zucchini also has a good bit more natural flavor than cucumbers, so they add more character to the finished pickles.
When making zucchini pickles for canning, the brine needs to be at least 50% vinegar (at 5% acidity) to be safe for canning. Salt, sugar, and seasonings are just for flavor, the canning safety comes from the vinegar.
I like using my bread and butter pickles recipe, simply substituting sliced zucchini for the cucumbers.
They’re sweet and tangy, and perfect on a homemade burger in the summer months.
Making relish with zucchini (or any other surplus vegetable) is pretty straightforward, given that it’s just diced produce preserved in vinegar, salt, and sugar.
Usually, other low acid ingredients like onion and red pepper are added, so be sure to use a tested zucchini relish canning recipe and stick to the proportions listed.
All tested recipes are going to include a good bit of vinegar, and it should be canning vinegar that’s standardized to 5% acidity. Be sure to check the label, as some canning vinegar comes “pre-diluted” and may only be around 3% acidity. Always check the label!
Zucchini in Pineapple Juice
This one’s really unique, and a truly creative way to preserve zucchini.
It also comes from the Ball Blue Book Guide to Preserving, which suggested either canning peeled zucchini chunks or grated zucchini in pineapple juice. It’s approved by the national center for food preservation, which lists zucchini pineapple as a safe canning recipe.
The juice adds both the acidity needed for safe water bath canning, as well as a good bit of sugar and flavor. Be aware that it also requires a good bit of lemon juice too, to bring the acidity down even further.
The finished zucchini pineapple tastes more or less exactly like pineapple, with just a hint of zucchini.
It’s perfect for use in carrot cakes that call for crushed pineapple, or zucchini bread (if shredded before canning, then drained before adding).
The ball blue book actually includes a recipe for pineapple zucchini donuts too, that uses shredded canned zucchini in pineapple juice that sounds downright amazing.
Zucchini Marmalade (Jam)
This one might be my favorite zucchini canning recipe, though it doesn’t use up that much of the harvest. You can only eat so much jam after all, and it only takes a few small zucchini per batch.
Still, this simple zucchini marmalade tastes like zucchini bread with a good bit of sweet lemon marmalade flavor from both the lemon juice and the lemon zest.
It also includes ginger, which helps bring out the “zucchini spice bread” flavor profile.
The lemon juice and peel acidify the zucchini, making it safe for water bath canning. They also add natural pectin, so this recipe comes together with just a few ingredients (and no boxed pectin).
Canning Zucchini with Tomatoes
This zucchini canning recipe is by far the most savory, but it will require a pressure canner.
(If you’re not familiar with pressure canning, I’d suggest reading this beginner’s guide to pressure canning before getting started.)
It’s good for use in casseroles, pasta dishes, and vegetable soup, but there’s less zucchini in the tested recipe than you might think.
By mixing 3 parts peeled and diced tomatoes with 1 part zucchini, it’s really almost more of a tomato canning recipe that includes zucchini.
There’s enough tomato in the jar to help acidify everything, though it’s still a pressure canning recipe. The structure of the tomato dices helps keep the zucchini chunks from matting together into a puree in the pressure canner.
The National Center for Food Preservation has instructions for canning tomatoes with zucchini.
Ways to Preserve Zucchini
Looking for a few more ways to preserve zucchini?
Summer Canning Recipes
Canning more than just zucchini this summer?