Fermented Watermelon Rind Pickles and Sweet Relish

Organic vs. Conventional Watermelon for Fermenting the Rind

I suggest using an organic in-season watermelon to make fermented watermelon rind. People often say that conventional watermelons are just as good as organic ones. However, that is because the rind protects the watermelon flesh from absorbing pesticides. Getting an organic watermelon is important since we are using the rind in this recipe, not the flesh.

You can use any type of watermelon and any size to make fermented watermelon rind.

Here’s my checklist for choosing a good watermelon:

1. Observe the stripes: Watermelon colors indicate ripeness. You should pick a melon that has a strong, consistent stripe pattern. The green stripes should be mostly solid green, while the pale stripes should be light yellow.
2. Field Spot: The field spot of the melon shows where the watermelon sat on the ground as it ripened. This is where soil microbes colonized the watermelon, and these microbes are vital to fermentation. Inspect your watermelon and locate a large, discolored spot on the surface. The color is usually yellow or near orange, which indicates a melon full of flavor. A good field spot means the rind is full of flavor too.
3. Check the Stem: This is for readers growing melons in their garden. When a watermelon has had sufficient time to ripen and mature, the stem should be dry and yellow-brown. A green stem means the watermelon is not yet ripe.
4. Dry spots: You may think you don’t want a melon with blemished rind for this recipe, but you do. Dry weathering spots and vein-like webbing on the rind indicate an extra sweet watermelon because these “blemishes” show where sugar has been seeping out of the fruit.

Probiotic Bacteria in Fermented Watermelon Rind

Similar to cucumbers, organic watermelons naturally have a lot of Lactobacillus plantarum on their surface. This means that watermelon rind ferments on a similar timeline to pickles. While cabbage takes four weeks to ferment, watermelon rind pickles take about two weeks.

You can ferment watermelon rind for longer if you want it to be more sour. The abundance of Lactobacillus makes fermented watermelon rind pickles excellent for gut health.

Preventing Sogginess When Fermenting Watermelon Rind

To help prevent sogginess, start with cold watermelon rind and a 3.5% total salt concentration. The most important thing you can do to keep any fermented pickles crisp is to use at least 3.5% total salt.

You can add bay leaves, sencha green tea, and grape leaves for tannins. Also, you can try adding calcium chloride salt, which is very effective at keeping things crunchy. (Some sources of calcium chloride are natural from limestone… and some are chemically produced. I suggest researching this salt and deciding if you’d like it in your food).

Supplies You Need to Make Fermented Watermelon Rind Pickles

Here is the equipment you will need to make it:

• 32-ounce Wide Mouth Mason Jar
• Fermentation Weight
• Standard Metal Mason Jar Lid (this can rust in the presence of salt)
• Try a Rust-Free Plastic Lid
• OR you can use a Weck Jar (without the gasket; only use the clips to secure the lid)
• Sea Salt
• Scale
• Mixing Bowl 
• Ripple cutter

If you would like to read more about the best jars and lids for fermenting vegetables, click here.

Fermented Watermelon Rind Timeline

We tracked our fermented watermelon rind pickles throughout the fermentation process. If you follow our recipe and directions, your timeline for fermented watermelon rind should approximately match ours. This timeline is for fermenting at 72-78 degrees F. The process will be slower in colder conditions and faster in warmer conditions.

24 – 72 hours: All contents in the jar should be submerged beneath the brine. At this time, there are still Gram negative bacteria and possible pathogens present. 
  
 72 hours – 7 days: After 72 hours, you should start to see lots of bubbles. You need to burp the jar if you are using a standard mason jar and lid. The colors on the rind change from vibrant green to pale olive. You will also notice the brine becomes very cloudy. Leuconostoc bacteria begin to thrive and produce a lot of carbon dioxide and acetic acid. Gram negative organisms die off during this time. 

7 – 12 days: Bubbles in the brine will decrease as the ferment leaves stage two and enters stage three. The mixture will become cloudy and start to develop a pleasantly sour smell. Lactobacillus species are most abundant during this time period.

12 – 14 days: Lactobacillus make up the majority or all of the microbial population. They produce copious amounts of lactic acid, and make the fermented watermelon rind smell even more pleasantly sour. This is the time in which the vegetable mixture becomes preserved. At this time, you can smell and taste test.

Fermented Watermelon Rind Pickles Recipe Tips

During the first few days of fermentation: carbon dioxide and bubbles will be produced. Sometimes jars will become full of liquid, and this liquid can seep out. You can store the jar in a bowl or on a plate to catch anything that seeps out.

Remove the lid and tamper everything using a gloved hand, tamper, or spoon if necessary. Make sure everything remains submerged below the brine during fermentation. You can take the lid off regularly and rinse it off if it is dirty.

Fermented watermelon rind should smell pleasantly sour and more smooth than a vinegar pickle. Never eat fermented foods that smell repulsive or like alcohol. 

How to Eat It

The texture of the outermost peel on the rind can be chewy and weird. It is perfectly edible, but I suggest chopping the fermented watermelon rind and incorporating it into a fine, sweet relish for the most pleasant texture. It’s great for hot dogs.

Sweet Fermented Watermelon Rind Relish with Onions

It’s best to chop it into a relish after fermentation because it’s easier to cut afterward. It’s also easier to submerge all the rind during fermentation if it is not finely minced.

Here is how to make it:

1. Strain the rind out, reserve some brine, and finely mince all of the watermelon rind.
2. Finely mince 1/2 a white onion.
3. Mix the watermelon rind and white onion with 1/4 cup of red wine vinegar, two tablespoons of honey, and two tablespoons of reserved brine.
4. Store in an airtight container and keep it in the fridge.
5. Use this delicious relish on burgers, hot dogs, salads, and in chicken salad.

More Watermelon Recipes

• How to Make Watermelon Wine with Honey (Watermelon Mead)
• Watermelon Goat Cheese Salad with Strawberries and Basil
• Caprese Melon Salad with Prosciutto and Mozzarella

Print