Preserving the Last of the Summer Tomato

text and photos by Allison Carroll Duffy

This has been a great growing season for most folks, it seems, thanks to the incredibly warm weather we had for much of the summer.  My vegetable gardens generally did well also–except for my tomatoes, which were quite another story.  For the past several years since moving to Portland, I’ve been gardening in our small, shady back yard.  I’ve managed to do alright with it, growing in modest raised beds that occupy the small sliver of yard that gets almost full sun for some of the day, and constantly moving our “portable gardens” (i.e. big black buckets filled with soil) around the yard in pursuit of the sun.  But it’s far from an ideal vegetable gardening scenario, and my husband and I have found ourselves increasingly yearning for the large, full-sun garden we used to have when we lived in the Midcoast.

So, this year we decided to get a community garden plot as well.  The plot was new, having been grass just the year before, and we were pretty sure the soil would need quite a bit of help.  We added a lot of manure and minerals.  I mulched with seaweed and went overboard with fish emulsion.  But sadly, our efforts were just not enough for the tomatoes.  They were spindly and a bit yellow, and the yield was disappointingly small.  I usually put up a decent amount of tomatoes, but this year I was hoping to preserve more than I usually do—kind of an experiment to see how much I’d actually need to get us through the winter.  Still set on my project, I purchased in bulk some canning-grade tomatoes from a local farm in late August.  I bought a crate—61 pounds to be exact.   I quickly realized that I’m accustomed to a more gradual influx of tomatoes over the course of a month or two as they ripen on the vine, and having the entire 61 pounds laid out on my dining room table all at the same time was quite a different thing indeed—beautiful, awe-inspiring, and panic-provoking all at once.

I managed to get through the crate before the tomatoes spoiled, and ordered a couple more to follow.    (Yes, I’ll admit to going a bit overboard, perhaps…..hopefully the results will be worth it!) I’m working my way through the third crate right now.  I’ve been canning whole and half tomatoes, crushed tomatoes, salsa, and sauce, and I have also frozen some tomatoes whole. These are just a few of the ways you can preserve tomatoes, and which method you choose is really a question of how you plan to use your tomatoes, as well as personal preference.  Canning crushed tomatoes is one of my favorite methods.  Once you get the hang of it it’s quite easy, and it results in a good, consistent product.  I also find crushed tomatoes to be especially versatile, working well in a variety of dishes.

One important thing to keep in mind any time you’re canning tomatoes is that tomatoes fall very close to the dividing line between high acid foods (those that have a pH of 4.6 or less), and foods that are considered low-acid (those that have a pH of greater than 4.6).  Given this, tomatoes need to be further acidified before processing in order to can them safely.  This can be done easily with the addition of bottled lemon juice or citric acid in specific proportions.  Please always follow a tested recipe to ensure that you are making and canning a safe product.  Tomatoes can be safely canned in either a boiling water bath canner, or in a pressure canner, though the processing time will vary.  The method below uses a boiling water bath canner.

Crushed Tomatoes

Please Note:
*If you are new to canning, please familiarize yourself with the safest and most up-to-date boiling water bath canning techniques, tools, and equipment.  The Ball Complete Book of Home Preserving (available at book stores), the Ball Blue Book Guide to Preserving (often available where canning supplies are sold—make sure to get the most up to date edition), and the National Center for Home Food Preservation are great resources for this.  They are also useful if you’re looking for other methods to preserve tomatoes, or for other recipes in general.

Bottled Lemon Juice

How much you’ll need of each ingredient depends, or course, on how many jars you want to can.  If you wish to make a full canner-load of seven quart jars, you will need about 19 pounds of tomatoes.  If you want to make less, keep in mind that you will need roughly 2 ¾ pounds of tomatoes per quart jar.  For lemon juice, you will need 2 Tablespoons of lemon juice per quart jar.  And, in case you’re wondering why the recipe calls for bottled lemon juice rather than fresh, it’s because bottled lemon juice has a standard level of acidity, while the acidity of fresh lemons can vary.

1.) Wash and rinse jars, lids, and screw bands.  Set screw bands aside until ready to use.  Place jars in hot water bath canner, fill at least 2/3 of the way full with water, and bring to a boil.  Sterilize jars for 10 minutes, and then turn down heat and let jars stand in hot water until ready to us

2.) Blanch, peel, and core tomatoes.  To do this, submerge a couple of tomatoes at a time in a pot of boiling water for 30-60 seconds, or until skins split. Remove the tomatoes from the boiling water and immediately immerse them in cold water. Slip off the skins, and then remove the core. Repeat this procedure for remaining tomatoes, working with just a few tomatoes at a time.

3.) Quarter several of the tomatoes—enough to equal roughly two cups—and place in the bottom of a large, stainless steel saucepan.  Heat the tomatoes while crushing them, and bring them to a boil.  A spatula, a potato masher, or a large spoon all work well for this.  (Ideally the utensil should be stainless steel or wood, though cooking-grade synthetic materials will also work.  Just avoid other metals, as they can react when in contact with tomatoes.)

4.) Quarter the remaining tomatoes and add them as you go to the pot, stirring and crushing the whole time. If you are using very large tomatoes, you may want to cut them into pieces smaller than quarters.  Once all tomatoes have been incorporated, boil for five minutes and stir frequently to prevent burning.

5.) Remove quart jars from canner, and add 2 Tablespoons bottled lemon juice to each jar.

6.) Promptly fill jars with hot tomatoes, leaving ½ inch headspace.  Remove air bubbles, and wipe jar rims.  Place dome lids and screw bands on jars and tighten just to fingertip-tight.  Carefully place jars back on the rack in the canner, ensure that water is covering all jars by 1-2 inches, cover with lid, and return water to a boil.  Process tomatoes at a full boil for 45 minutes.  (NOTE: If you are at an altitude over 1000 feet, the processing time must be increased.  If you’re at 1001—3000 feet above sea level, process quarts for 50 minutes, if you’re at 3001—6000 feet process quarts for 55 minutes, and if your location is over 6000 feet above sea level, process for 60 minutes.)

7.) After processing, turn off heat and allow canner to sit undisturbed for 5 minutes.  Then, carefully remove jars and place on cooling rack or towel.  Allow jars to sit undisturbed for 12-24 hours.

8.) After 12-24 hours, check jars to confirm that they have sealed properly.  Then remove screw bands, rinse jars, label, and store for up to one year.