Many people love the bright, fresh taste of watermelon, and melons such as cantaloupe and honey dew. Just the taste has a way of making you feel cooler in summer, and can remind you of high summer in the midst of winter.
Many home-canning recipes even turn the rind into a pickle, so nothing is wasted.
Melons, though, in addition to all being notoriously hard to tell when they are perfectly ripe, also have another aspect in common: they all are classed as a low-acid fruit and consequently require special treatment when used in home canning.
- 1 Why do melons require special treatment in home canning?
- 2 Tested recipes for home canning watermelon and other melon
- 3 Watermelon Varieties
- 4 pH of Melons
- 5 Documented botulism outbreak from watermelon jelly
- 6 Sources
Why do melons require special treatment in home canning?
The reason for the special treatment is that in a low-acid environment such as the melon family provides, botulism spores can germinate and release the toxin that causes botulism in people (and animals.) This is not theoretical; it has happened. Such low-acid home-canned fruit must have its acidity raised in order to prevent this. (Asian pears, ripe mango, and figs share the same requirement.)
Don’t play with the health of your family and friends by using any old “hipster” or “old-family” recipe for home-canned watermelon and melons off the Internet. There’s nothing “hip” or “quaint” about botulism.
Here’s a sample list of tested recipes from reputable sources.
Tested recipes for home canning watermelon and other melon
What all these recipes will have in common is enough added acidity to make the melon acidic, and push it way down below the safe cut-off point of a 4.6 pH. For shelf-stable home canning purposes, be sure to use only modern tested recipes from reputable sources, that will have verified that a safe pH is being achieved.
USDA Complete Guide
United States Department of Agriculture (USDA). Complete guide to home canning. Agriculture information bulletin No. 539. 2015.
- Cantaloupe pickles, page 2-11.
So Easy to Preserve
Elizabeth L. Andress and Judy A. Harrison. So Easy to Preserve. University of Georgia Cooperative Extension. Bulletin 989. Sixth Edition. 2014.
- Cantaloupe pickles, page 152.
- Watermelon Rind Pickles, page 157.
- No-Sugar-Added Cantaloupe Pickles, page 179.
- Watermelon Rind Preserves, page 226.
Ball Blue Book
Ball Blue Book. Muncie, Indiana: Healthmark LLC / Jarden Home Brands. Edition 37. 2014.
- Golden Nectar Juice (with cantaloupe), page 29.
- Citron Melon Preserves, page 65.
- Spicy Melon Pickles, page 85.
- Watermelon Rind Pickles, page 85.
- Curried Fruit Compote (with cantaloupe), page 134.
Ball All New
Butcher, Meredith L., Ed. The All New Ball Book of Canning and Preserving. New York: Oxmoor House. 2016.
- Melon Jam, page 44.
- Watermelon, Cucumber and Jalapeno Pickles, page 222.
Bernardin Guide to Home Preserving. Toronto, Canada: Bernardin Ltd. 2013.
- Cantaloupe Pickles, page 172.
- Cinnamon Watermelon Pickles, page 173.
Ball / Bernardin Complete
Judi Kingry and Lauren Devine. Ball / Bernardin Complete Book of Home Preserving. Toronto: Robert Rose. 2015
- Zesty Watermelon Jelly, page 117.
- Curried Fruit Compote (with cantaloupe), page 168.
- Cantaloupe Pickles, page 299.
- Cinnamon Watermelon Rind Pickles, 327.
- Watermelon Jelly. (link valid as of May 2017)
The Joy of Pickling
Linda Ziedrich. The Joy of Pickling. Boston, Massachusetts: Harvard Common Press. 2016. Third edition.
- Brined Whole Watermelon, page 105.
- Mango-melons (aka orange-melon, vegetable-peach, plum granny, vine pomegranate, Queen Anne’s pocket melon), page 174 to 175.
- Esther’s Fresh-Pickled Red Watermelon, page 191.
- Gwen’s Fresh-Pickled Red Watermelon with Dill and Garlic, page 193.
- Gingery Watermelon Pickles, page 278.
- Minty Watermelon Pickles, page 280.
- Dark Watermelon Pickles, page 281.
- Sweet Pickled Citron Melon, page 282.
- Quick Pickled Watermelon, page 339.
The Joy of Jams
Linda Ziedrich. The Joy of Jams, Jellies and Other Sweet Preserves. Boston, Massachusetts: Harvard Common Press. 2009.
- Cantaloupe and Muskmelon preserves, page 82 to 86.
- Watermelon Preserves, page 349.
- Watermelon Molasses, page 350.
- Watermelon Rind Preserves, page 351.
Linda Ziedrich writes,
…descendants of Germans from Russia in the US Midwest have a favorite watermelon for fresh pickling as well as for brining: ‘Winter King and Queen’ [Ed: that’s all one name.] In early catalogs from Gurney Seed and Nursery…. Winter King and Queen was called simply Winter Melon. Later it was called Christmas Melon. …. it’s a long keeper, one that with no special treatment will keep well until as late as February. Winter King and Queen is good for pickling, too, because its relatively coarse flesh doesn’t soften as much as the flesh of other watermelons…. The melons average about 10 pounds (4 kg) in weight. At this writing, seeds of Winter King and Queen are available from Adaptive Seeds (www.adaptiveseeds.com)… Seedless watermelon varieties make acceptable substitutes, at least for fresh pickling provided they are a bit underripe.”1
She adds that the rind on the Winter King and Queen Watermelon is tough, but thin.
pH of Melons
Background refresher: for home canning, any pH below 4.6 is considered high acid; anything above that is considered low-acid. 4.6 is the uppermost cut-off point for safe water-bath (or steam) canning. And remember that the pH scale, like the Richter scale, is logarithmic: small increments matter a lot. Each .1 increase or decrease in value is ten times more or less than the next higher value. So even 5.18 is very far above the safe cut-off of 4.6.
- Cantaloupe 6.13 – 6.58
- Casaba Melon 5 .78 – 6.0
- Honey Dew Melons 6.00 – 6.67
- Persian Melons 5.90 – 6.38
- Watermelon 5.18 – 5.60
Source: FDA. Approximate pH of Foods and Food Products. April 2007. Accessed March 2017 at http://foodscience.caes.uga.edu/extension/documents/FDAapproximatepHoffoodslacf-phs.pdf
Documented botulism outbreak from watermelon jelly
In 2011, in British Columbia, Canada, watermelon jelly caused a botulism outbreak. The jelly was made by a small business, Jamnation Fine Foods, and was being sold at booths around the province to raise money for the British Columbia Huntingtons Research Foundation. A recall was issued. Further investigation resulted in the recall being expanded to all the Jamnation products.
Health investigators determined that what allowed the botulism to occur was that the watermelon juice was not properly acidified to safe pH levels (4.6 or lower) before the jelly was made and canned.
CBC News. Botulism warning issued for watermelon jam. 8 March 2011. Accessed May 2017 at http://www.cbc.ca/news/canada/british-columbia/botulism-warning-issued-for-watermelon-jam-1.1123071
Food Safety News. Watermelon Jelly Linked to Botulism in Canada. 9 March 2011. Accessed May 2017 at http://www.foodsafetynews.com/2011/03/bc-jelly-may-be-contaminated-with-botulism/#.WSxnGWjyu70
Outbreak Database. British Columbia Jamnation Watermelon Jelly 2011. Accessed May 2017 at http://www.outbreakdatabase.com/details/british-columbia-jamnation-watermelon-jelly-2011/
Rusland, Peter. Potentially deadly botulism sends woman to hospital. 8 March 2011. Accessed May 2017 at http://www.bclocalnews.com/news/117598213.html?mobile=true
Watermelon jelly warning. Prince George, British Columbia, Canada: Prince George Citizen. 8 March 2011. Accessed May 2017 at http://www.princegeorgecitizen.com/news/local-news/watermelon-jelly-warning-1.1088033
Watts, Richard. Botulism alert over jelly after Island woman falls ill. Victoria, British Columbia: Times Colonist. 9 March 2011. Accessed May 2017 at https://www.pressreader.com/canada/times-colonist/20110309/282969626572085
Ziedrich, Linda. The Joy of Pickling. Boston, Massachusetts: Harvard Common Press. 2016. Third edition. Page 191. ↩