Yep, I still have a LOT of tomatoes to put up.  We’ve had some beautiful days, so Connor and Ian have been helping me wash the tomatoes outside in the back yard, and I’ve been using my portable burner on a table outside for blanching and skinning them.  (Gotta take advantage of the weather while we have it–here in Maine, we won’t have days like these for much longer…) I’ve been making all kinds of different things with the tomatoes, and preserving them lots of different ways, trying to work my way through them all. (The tomatoes were eventually banished from the kitchen table–hard to eat dinner, I admit–and the yet-to-be-used ones are now again living contentedly in the crate on our kitchen floor, in case you were wondering)  One of my favorite ways of preserving them is to make canned crushed tomatoes.  Perhaps it’s just personal preference, but I find crushed tomatoes to be one of the easiest ways to can tomatoes, and I find that the results are very consistent.  They’re also really versatile, working well in soups, stews, casseroles, curries, pasta and rice dishes, and all sorts of things.

On important thing to know about canning tomatoes is that they always need to be further acidified before processing them in order for them to be safe.  This is because tomatoes fall close to the dividing line between high acid foods (those that have a pH of 4.6 or less), and low-acid  foods (those that have a pH of greater than 4.6).   You can do this easily with the measured addition of bottled lemon juice or citric acid to the canning jar before processing.  My preference is bottled lemon juice, primarily because I always have it on hand anyway, so I find it the most convenient.  All I need to do is to add two Tablespoons per quart jar and all is good–it’s easy.  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
(Makes 7 quart jars of tomatoes)

20 pounds of fresh, whole tomatoes
Bottled lemon juice (2 Tablespoons per quart jar)

1.) Wash and rinse jars, lids, and screw bands.  Set screw bands aside until ready to use.  Place lids in water in a small sauce pan.   Bring them to a simmer and hold at a very low simmer 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 use.

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.

CAnning tomatoes, Sept. 2, 2010, 1

CAnning tomatoes, Sept. 2, 2010, 2

CAnning tomatoes, Sept. 2, 2010, 3

CAnning tomatoes, Sept. 2, 2010, 4