Green Tomato Ketchup

Homemade green tomato ketchup is a delicious way to preserve the last of your summer tomatoes and enjoy their tangy goodness well into the fall and beyond. Whether you’re canning a few jars to keep on hand for your own family or sharing them with loved ones, this recipe makes a wonderful, unique condiment that’s sure to stand out at any meal.

As summer fades and the cooler weather sets in, many home gardeners find themselves with an abundance of green tomatoes that never quite ripened. Instead of letting them go to waste, why not transform them into something delicious? Homemade green tomato ketchup is a fantastic way to preserve those unripe tomatoes, turning them into a tangy, sweet, and slightly spicy condiment that pairs perfectly with burgers, sandwiches, fries, and more.

This homemade ketchup combines the bright acidity of green tomatoes with the savory flavor of onions, vinegar, and spices. It’s a great alternative to traditional ketchup and an excellent way to use up those end-of-season tomatoes. Plus, it’s surprisingly easy to make!

Ingredients for Green Tomato Ketchup

To make a small batch of about 2 pints, you’ll need the following:

• 6 pounds of green tomatoes (about 12 medium tomatoes)
• 1 1/2 cups onions, chopped (about 1lb or 1 large onion)
• 1 Tbsp dry mustard
• 1 tsp Worcestershire sauce
• 2 tsp mixed pickling spices (optional, but recommended)
• 1 tsp black pepper
• 1 1/2 cups Apple Cider Vinegar
• 3/4 cup honey (or to taste)
• 1 Tbsp Kosher salt (or to taste)

I’ve written this as a small batch recipe, but feel free to increase the recipe as much as you like. Your yield will be better if you use roma or paste tomatoes, the same type you use when making regular ketchup, but you can use whatever green (unripe) tomatoes you have on hand.

You can substitute white vinegar in place of the apple cider vinegar if that’s all you have available.  White vinegar has a more neutral flavor, but it’s acidity tastes a bit harsher.  Apple cider vinegar adds a nice flavor to the ketchup, rounding it out without being overbearing.

The mixed pickling spices really add a wonderful flavor to the ketchup, and they’re usually added whole in a small sachet and removed later.  If you don’t have any on hand, a pinch of cinnamon and allspice will help round out the flavor.  (Mixed pickling spices have a lot of different flavors in there, so go with those if you can find them.)

How to Make Green Tomato Ketchup

Begin by gathering all your ingredients. Slice or chop the green tomatoes and onions into small pieces. Place them in a large Dutch oven or stockpot. Add the black pepper, dry mustard, Worcestershire sauce, and mixed pickling spices (if using). To contain the pickling spices, place them in a small cheesecloth bag so they’re easier to remove later.

Pour the vinegar over the vegetables and spices, and stir to combine.  (At this point, the only ingredients missing are honey and salt.)

Place the pot over low heat and allow the mixture to cook gently for about 4 hours. Stir occasionally, making sure everything is cooking evenly. The long cooking time will help break down the tomatoes and onions, allowing their flavors to meld together into a rich, savory base for your ketchup.

Once the tomatoes and onions have softened and cooked down, it’s time to blend the mixture into a smooth consistency. You can do this in batches using a traditional blender or a stick blender (immersion blender).  If using a traditional blender, be sure to only fill it one-third full at a time to avoid splattering hot ingredients. Vent the lid and cover it with a kitchen towel to keep steam from escaping.

I actually like to run it through a food mill, as it gives it a nice even consistency.  It’s the same food mill I use for making tomato paste, tomato sauce and spaghetti sauce.

After blending, strain the ketchup mixture through a fine mesh strainer set over a large bowl.  (If you’ve used a food mill, straining is part of the mixing step.  If you used a blender, you’ll need to pull out the tomato seed and skin pieces.) 

This step removes the seeds and solids, leaving you with a smooth, liquid ketchup base.

Return the strained ketchup mixture to the Dutch oven or stockpot. Bring it to a boil over medium-high heat, then reduce the heat to low. Add the honey, which will help balance the tartness of the tomatoes, and stir well. Taste the ketchup and add kosher salt as needed to enhance the flavor.

Continue cooking the ketchup uncovered over low heat, stirring occasionally, until it thickens to your desired consistency. This can take anywhere from 30 minutes to an hour, depending on how thick you want your ketchup to be.

While the ketchup is thickening, prepare your canning equipment. Fill a water bath canning kettle with water, making sure it’s enough to cover your jars by at least 2 inches. Bring the water to a boil and then reduce the heat to low.

Place your canning jars in the kettle to sterilize them, and let them stay in the hot water until you’re ready to fill them.

Next, place the sealing lids in a saucepan, cover them with water, and bring to a gentle boil. Once the lids are heated, remove the saucepan from the heat.

Once the ketchup has thickened, it’s time to can it. 

Using a funnel, pour the hot ketchup into the jars, leaving about ¼ inch of headspace at the top.  You may use pints or half pint jars, but do not use jars larger than pint.

Wipe the rims of the jars with a clean damp cloth to ensure there’s no ketchup residue that might prevent the lids from sealing. Place the hot sealing lids on top of the jars, then screw on the rings, tightening just until “finger-tight” (don’t over-tighten).

Place the filled jars into the water bath canner. The water should cover the jars by at least 2 inches. Bring the water to a boil and process the jars for 15 minutes, adjusting for altitude (see below).

Once the processing time is complete, carefully remove the jars from the water bath using a jar lifter. Allow them to cool completely on a clean towel. As the jars cool, you should hear a satisfying “pop” as the lids seal.

After the jars have cooled for 24 hours, check the seals by pressing down on the center of each lid. If the lid does not pop back, the jar is sealed and can be stored in a cool, dry place for up to one year. Any unsealed jars should be refrigerated and used within 3 months.

Altitude Adjustments

The altitude adjustments for canning ketchup are as follows:

• For 0 to 1,000 feet in elevation process jars 15 minutes
• For 1,001 to 6,000 feet in elevation process jars 20 minutes
• For 6,001 to 8,000 feet in elevation process jars 25 minutes
• Above 8,001 feet process jars for 30 minutes

This recipe can be processed in pints or any jar smaller than a pint. Do not process in jars larger than pints.

How to Use Green Tomato Ketchup

Green tomato ketchup has a versatile tangy-sweet flavor that pairs beautifully with a wide variety of dishes. Here are a few ideas to try:

• Burgers and Sandwiches: Use it as a zesty topping for your favorite grilled meats or veggie burgers.
• Fries and Chicken Fingers: Serve it as a dip for crispy fries or chicken tenders for a fresh take on traditional ketchup.
• BBQ Sauces: Mix it with a bit of mustard or vinegar for a homemade barbecue sauce that’s great for grilled chicken or ribs.

I’m particularly fond of green tomato ketchup with sweet potato fries!

So, next time you find yourself with a pile of green tomatoes at the end of the season, don’t toss them—turn them into homemade ketchup instead!

Green Tomato Canning Recipes

Looking for more ways to use up green tomatoes at the end of the season?

Green tomato salsa verde is a unique twist on salsa. Usually salsa verde is made with tomatillos, but it works just as well with green tomatoes. Green tomato chutney is a lovely savory condiment too, and it’s quite similar to this ketchup (but chunky).

Pickled green tomatoes are great beside heavy meals, adding a bright pop to your plate. And you can even can green tomato slices for frying later on!

If that’s not enough, I have an article with more than 20 green tomato canning recipes to stock your pantry.