Spicy Zucchini Relish with Horseradish

Make this spicy zucchini relish with horseradish and jalapeño for bold flavor. A safe water bath canning recipe made with fresh garden zucchini.

If your garden is overflowing with zucchini, this spicy zucchini relish is a flavorful way to put it to good use. It has a bold, tangy bite from horseradish and a hot chili pepper, making it a great alternative to traditional sweet pickle relish.

I first shared my original Zucchini Relish recipe back in 2009, and it remains one of the most popular canning recipes on Grow a Good Life. But over the years, this zesty version has become a new favorite in our kitchen, especially at summer cookouts. It adds just the right amount of kick to hot dogs, burgers, sausages, sandwiches, and even slow cooker meals in winter.

If you enjoy pickled vegetables with personality, you’ll love this lively zucchini relish. In this guide, I’ll walk you through how to make and safely can spicy zucchini relish step by step, even if you’re new to canning.

Why You’ll Love this Spicy Zucchini Relish

• Bold and zesty flavor: Horseradish and chili pepper add warmth without overpowering.
• A great way to use garden zucchini: Perfect for dealing with midsummer overload.
• Safe, tested recipe: Adapted from the trusted Ball Complete Book of Home Preserving.
• Flexible jar sizes: Can be preserved in pints or half-pints.
• Versatile condiment: Adds zip to hot dogs, burgers, grilled meats, sandwiches, charcuterie boards, and more.

About the Ingredients

Here is an overview of the ingredients you will need to make about 5 pints of this spicy zucchini relish:

Zucchini

Choose healthy, fresh zucchini. You will need about 4 1/4 pounds of zucchini (about 5 medium) to yield 12 cups of finely chopped zucchini.

Onions

Onions add savory depth and balance the heat in this relish. Yellow onions work well, but white or sweet onions may also be used. You will need about 1 1/2 pounds, or about 5 medium onions to get 4 cups of chopped onions after preparation.

Bell Peppers

This recipe uses both red and green bell peppers. Red bell peppers add a pretty pop of color along with their mild, sweet flavor, while green bell peppers bring a classic peppery flavor.

Jalapeño or Hot Chili Pepper

A single jalapeño pepper (or similar sized chili) adds a mild kick. Feel free to use a hotter pepper like serrano or cayenne if you prefer more heat.

Horseradish

Prepared horseradish gives this relish a bold, tangy flavor and a little heat. For convenience, you can use prepared horseradish from the grocery store. Just choose one made with horseradish, vinegar, and salt only. If you have access to fresh horseradish root, you can make your own prepared horseradish at home.

How to Make Prepared Horseradish: If using fresh horseradish root, you’ll need about a 4 to 5-inch piece to yield 1/4 cup prepared horseradish for this recipe.

1. Peel the horseradish root and cut it into chunks.
2. Add to a food processor with 2 tablespoons of vinegar and a pinch of salt.
3. Process until finely grated, adding a little more vinegar if needed.

Tip: Wear gloves and work in a well-ventilated area. Fresh horseradish fumes are strong and can irritate your eyes and sinuses.

Pickling or Canning Salt

Salt helps draw moisture from the vegetables during the first step, improving texture and flavor. Use pure salt labeled as pickling or canning salt. Iodized salt or salt with added ingredients may affect the flavor. Don’t worry, you will rinse out most of the salt before making the relish.

Vinegar

This is a high-acid canning recipe, so vinegar is essential for safety. Use distilled white vinegar (5% acidity) for the cleanest flavor and proper preservation.

Sugar

Sugar softens the vinegar’s acidity and brings the flavors together. It does not affect the recipe’s acidity level, so it can be safely reduced or increased slightly to taste.

Spices

Ground nutmeg and turmeric add warm undertones and classic relish flavor. The turmeric also gives this relish a vibrant yellow color.

Safe Adjustments

You can safely adjust some of the ingredients in this spicy zucchini relish canning recipe to suit your taste, as long as you keep the total amount of vegetables and vinegar the same to maintain proper acidity for water bath canning.

• Zucchini: You can substitute an equal amount of yellow summer squash. It will change the color, but it still works well in relish recipes.
• Onions: Use any type of bulb onion, including yellow, white, or red. Sweet onions, such as Vidalia or Spanish, may also be used, but keep the total amount the same.
• Peppers: You can swap bell peppers and the hot chili pepper for other varieties in equal amounts. For example, use Anaheim or Cubanelle peppers instead of bell peppers, or substitute serrano or cayenne for jalapeño.
• Vinegar: This recipe uses distilled white vinegar (5% acidity), but you can substitute it with another commercial 5% vinegar, such as apple cider vinegar, for a slightly mellower flavor.
• Sugar: This relish is only lightly sweet. You can reduce the sugar slightly for a tangier result or increase it up to 2 1/2 cups for a sweeter relish. Brown sugar also works for a richer flavor.
• Spices: You can safely reduce or omit the nutmeg, turmeric, horseradish, or chili pepper for a milder relish. If you prefer more heat, you can safely add dried red pepper flakes.
• Jar Size: This recipe may be safely canned in either pint or half-pint jars. Processing time is the same for both.

If you’d like to learn more about safe adjustment guidelines, see this article: How to Modify Pickle and Relish Canning Recipes Safely.

Steps for Making Spicy Zucchini Relish

This recipe is adapted from the Zesty Zucchini Relish in the Ball Complete Book of Home Preserving. Like many relish recipes, this one is a two-day process. On day one, the vegetables are salted to draw out excess moisture. On day two, the relish is cooked, packed into jars, and processed in a boiling water bath canner.

If you’re new to water bath canning, you may find it helpful to review the basics before getting started. See my step-by-step guide: Water Bath Canning for Beginners.

To make your canning project easier, I also have a free Home Canning Checklist you can print and use to stay organized. It includes safety reminders, prep steps, and space to track your batches. Get it here:

You can find the complete printable recipe at the bottom of this post, but here are the detailed step-by-step instructions:

Step 1: Gather Your Kitchen and Canning Equipment 

Gather and prepare your kitchen and canning equipment. You will need:

• Water bath canner with a canning rack
• 5 pint-sized canning jars or 10 half-pint jars (Relish yields can vary, so prepare extra jars)
• Canning lids and ring bands (new lids for each jar; bands can be reused) 
• Canning tools: jar lifter, canning funnel, bubble popper/headspace measurer
• Large canning ladle
• Kitchen scale
• Food processor (optional, makes chopping easier)
• Large non-reactive bowl (stainless steel or glass)
• Large non-reactive stock pot
• Food-safe gloves for handling horseradish and hot peppers
• Basic kitchen tools: knife, cutting board, large colander, measuring cups and spoons, ladle, clean towels

Wash the canner, jars, lids, rings, and tools in warm, soapy water. Rinse well, and set aside to air dry on clean kitchen towels. Check over the jars and eliminate any with nicks, scratches, or cracks. Pay careful attention to the rims of the jars. Minor nicks can prevent the lids from sealing.

Set the clean canner, jars, and canning equipment aside for now. You will use them the following day to can your relish.

Step 2: Prepare the Vegetables (Day 1)

A quick and easy way to prepare the vegetables is to pulse them in a food processor until finely chopped. If you don’t have a food processor, you can use a box grater to shred the vegetables, or use a knife and a cutting board to chop.

Rinse the zucchini and bell peppers well under cool, running water and set aside on a towel to air dry. Then prepare and measure each ingredient individually.

Zucchini

You will need about 4 1/4 pounds of zucchini to yield 12 cups of finely chopped zucchini. If your zucchini is large, cut it in half and scoop out the spongy seed cavity before weighing. If the skin is hard, you may wish to peel it first to avoid unwanted texture in your relish.

Weigh the zucchini, then finely chop it using a food processor or knife. Measure as you go and add 12 cups of finely chopped zucchini to a large prep bowl.

Onions

Peel and chop your onions using a food processor or knife. Measure and add 4 cups of chopped onions to your prep bowl along with the zucchini.

Bell Peppers

Remove the stems, ribs, and seeds, and chop the peppers using a food processor or a knife. Add the chopped bell peppers to your prep bowl.

Add Salt and Let Soak

Sprinkle with pickling salt and mix well. Cover and refrigerate overnight to draw out excess moisture.

Step 3: Make the Relish (Day 2)

Measure and add the sugar, vinegar, nutmeg, turmeric, and horseradish to a large saucepan. While wearing gloves, chop your chili pepper and add it to the pot.

Remove the zucchini, onion, and pepper mixture from the refrigerator, and dump it into a colander in the sink. Rinse well with cool water to remove excess salt, and drain well.

Use your hands to press out as much liquid as you can, then add the drained vegetables to the large saucepan and stir to combine.

Bring the pot to a boil over medium-high heat, then reduce to a gentle simmer. Cook uncovered for about 45 minutes, or until most of the liquid has evaporated and the relish thickens.

Step 4: Prepare the Canner and Jars

When your relish is almost ready, set up your canner. Place your water bath canner on the stove, add the jar rack, and set the clean jars upright on the rack.

Fill the canner with enough water to cover the jars. Bring the canner to a simmer (180˚F), simmer for at least 10 minutes, and keep warm as you fill your jars.

Step 5: Fill the Jars with Relish

Prepare your work area by placing a dry towel on the counter, and the lids, bands, canning tools, and a clean, damp paper towel within reach.

Use the jar lifter to remove a warm jar from the canner, draining the water back into the canner. Place the jar on the towel. Use the funnel and ladle to fill the warm jar with hot relish, leaving 1/2-inch of headspace.

Slowly run the bubble popper through the jar to release any air bubbles. Wipe the rim with a damp paper towel, place the lid on the jar, and screw on the band until fingertip tight. Place the filled jar back into the canner, then repeat with the remaining jars.

Step 6: Process in a Water Bath Canner

Once all the jars are filled and placed back into the canner, adjust the water level so they are covered by at least two inches of water. Add the cover, and bring the canner to a rolling boil.

Once the water boils vigorously, set a timer and process the jars in a boiling water bath canner for the times indicated in the recipe below, adjusting the processing time for altitude if needed.

Step 7: Cool and Store

When the processing time is up, turn off the heat and remove the lid. Let the canner settle for 5 minutes to adjust to the temperature change. 

Spread a dry towel on the counter. Then, use the jar lifter to remove the jars and place them on the towel, spacing them a few inches apart. Keep them upright as you lift them out of the canner and onto the towel, and don’t touch the lids or bands yet.

Let them cool undisturbed for 12 to 24 hours. After at least 12 hours, check the seals by pressing the center of each lid. If the lid does not pop up, the jar is sealed.

Wash the jars to remove residue, then store the sealed jars in a cool, dark place for 12 to 18 months. Give the relish 2 to 4 weeks to develop flavor. Store opened jars, and any jars that failed to seal in the refrigerator, and use them within a month.

Ways to Use Spicy Zucchini Relish

This spicy zucchini relish adds bold, tangy flavor to all kinds of dishes. Try it in these simple ways:

• Serve as a classic condiment for hot dogs, hamburgers, and grilled sausages.
• Stir into tuna, chicken, or egg salad for a flavorful twist.
• Spoon over grilled meats, bratwurst, or roasted vegetables for extra zip.
• Add a spoonful to deviled eggs or potato salad for a pop of color and heat.
• Use as a sandwich or burger spread in place of mustard or pickles.
• Mix with mayo or sour cream to make a quick relish dip or sandwich spread.
• Pair with cheese and crackers on a charcuterie or snack board.
• Add to slow-cooker pulled pork or baked beans for a tangy flavor.

This spicy zucchini relish is a bold and flavorful way to preserve your garden harvest. The combination of zucchini, bell peppers, onions, horseradish, and chili pepper creates a tangy relish with just the right amount of heat. Whether you’re topping burgers at a summer cookout or spooning over roasted meats and vegetables, this relish adds a punch of homemade flavor to any meal.

If you enjoy making your own pantry staples, you may also like these other relish recipes:

• Classic Sweet Zucchini Relish: Sweet, traditional relish with garden flavor
• Dill Cucumber Pickle Relish: Crisp, garlicky, and perfect for hot dogs
• Sweet Summer Squash Relish: A great alternative when zucchini is scarce
• Sweet Cucumber Relish: A classic for sandwiches and potato salad
• Looking for more ways to preserve zucchini? Check out this post: Ways to Preserve Zucchini.