early girl tomatoes

For the past month, every meal I’ve had at home has included tomatoes in some form. I’m not exaggerating. This time of year brings out the greedy tomato monster in me, and I just gorge on them until they vanish from the stands of farmers’ markets.

I’m not alone in my obsession, and I’m particularly fond of Early Girl tomatoes. This year I resolved to eat these red jewels as long as possible and decided to finally make the time to stockpile them in my pantry. Wintertime won’t be as bleak knowing that I have a stash of tomatoes to brighten my dishes on occasion.

This past Saturday morning, I bought a crate of dry-farmed Early Girls from Dirty Girl Produce at the Ferry Building (be sure to ask for the ones for canning, they’re cheaper!) and hauled 20 pounds home in my bicycle panniers. I set aside the rest of the afternoon for this enterprise because canning is an all-day affair, especially if you’re planning on doing a large batch (and you should, since it’s so time-consuming.)

I had already stocked up on Weck jars from Weckjars.com; I confess part of my impetus for canning tomatoes this season was that I have a deep affection for these beautiful German jars. You might have spotted them at Heath Ceramics or Crate and Barrel. (They’re available on plenty of other online retailers as well, so search around if you can’t find them locally.) They’re pricier than Ball and Kerr jars, but the lids are reusable as long as you don’t crack them. (Ball and Kerr jars lids are one-time use only.)

Weckjars.com was kind enough to provide me with a home-canning guide that was immensely useful and included recipes for a variety of jams, preserves and pickled food. Here’s a run-down of the essentials:

1) You need a large pot that’s deep enough to accommodate both a rack that you can rest in the bottom and the jars. The jars will rest on this rack and should be completely submerged in water when processing.

2) You’ll also need a jar lifter to remove the jars from hot water with ease.

3) Be sure all of your jars are in pristine condition and have been thoroughly cleaned with hot, soapy water. If you see any mold (from being stored in a damp cellar, for instance), boil them for 10 minutes. Always use new rubber rings, and they should have no cracks or tears. Boil the rubber canning rings for 2-3 minutes and leave them in the hot water until you need them.

4) Prep your tomatoes. Chop them up and can them raw, or blanch them to remove the skins, make a sauce, roast them…the possibilities are endless. I like the skins and don’t mind seeds, so I just sliced mine up, then roasted them in the oven with olive oil and salt.

5) Fill your jars up almost to the top (I left approximately 1/8″ of room, Weck recommends 1/2″ but I thought that was too much); you want to be sure that the lids don’t squeeze any liquid out when you press them down. Wipe down the rims, then add the lids with the rubber canning rings. Be sure the rings are evenly seated around the lid and don’t poke up anywhere. This is very important as it will insure a tight seal later on. Weck jars use rust-proof metal clamps to secure the lids during processing. Clamp two of them on top on opposite ends of the lid. Be sure to completely press down so that they click firmly in place.

tomatoes ready for canning

6) If you’re packing raw tomatoes, you must submerge the jars in room temperature water and bring it to boil. Once the water’s boiling (212 °F), you must process them for 90 minutes. For cooked tomatoes, bring the water to a boil and then gently submerge the jars for 50 minutes. You may notice that the volume of your tomatoes has decreased slightly due to the processing stage, as steam and occasionally liquid may leave the jar (but won’t enter in.)

7) Don’t stack jars on top of each other; be sure to use another rack if you add a second level of jars. It’s ok for the jars to touch one another and the walls of the pot itself. However, don’t pack them in too tightly. Leave some room so you can remove them easily.

remove jars from pot

8) Remove the jars with the lifter and let them cool completely. Then remove the clamps and test the lids. Here’s the moment of truth: they should be firmly in place, and the tab of the rubber canning ring should be pointing downward. If the lids have any give, refrigerate this batch and start over. Store your jars in a cool, dry place away from sunlight and periodically test the lids of your jars over the next few days to ensure they’ve successfully sealed. If you notice that the tabs are level, check the seal — it may be loose. I’d avoid consuming any tomatoes if you feel the seal has been compromised. You don’t want to get sick and not be able to eat the good ones over the next few months.

9) When you’re ready to eat your tomatoes, pull on the rubber tab to break the seal. You’ll hear a satisfying pop and you can feast away.

finished canned tomatoes

If you’re feeling a bit on the lazier side, you can always freeze your tomatoes, too.

Good luck and happy hoarding!


Prevent Wintertime Tomato Deprivation and Create a Canned Collection 22 August,2012Jenny Oh

  • Chris C.

    Lovely. Two things, though, for safe canning. First, it’s really, really important with today’s tomatoes to add acid to them before canning. They’re simply not consistently acidic enough to be safe without it. This is probably not something your grandmother/mother did, but tomatoes in the past were more acidic than the heirloom/dry farmed varieties we have today. You should add 1 tbs of lemon juice for each pint of tomatoes, per the USDA. This will help prevent botulism, which tomatoes are particularly prone to, and which can make you very, very sick.

    Also, 1/8 inch is just not enough headspace in a jar. You should always follow manufacturer/recipe instructions on this, because that space is needed to ensure a good seal. If you fill the jars too full, the product can touch the top of the jar while you’re heat sealing the jars (when they start boiling), preventing a good seal. It can also lead to jars that explode and/or overflow when you pull them out of the canner. Ouch!

    • Thanks for your comments, Clark! I also consulted some other recipes and friends who have canned tomatoes recently, and the lemon juice seemed to be optional step. It’s definitely not a bad precaution to take if one is worried about the acidity. And I found with the Weck jars, as long as there was enough room so that the liquid didn’t touch the lid and overflow, the volume of liquid shrunk down a bit during processing so that a tight seal was created. It’s probably different for Ball or Kerr jars. 1/2″ seemed too much for me, but it probably depends on whether you’re processing raw or cooked tomatoes also.

  • Thank you for the detail. I have never canned anything before but do have a stock pile of heirloom tomatoes this year. I took a bit of a systematic approach and now am reaping a huge harvest with more than I can ever use. See details here -> http://goo.gl/wXVqr . This would be great to can and enjoy the bounty throughout winter! Excellent info and thanks for sharing!

  • I just put up 12 lbs of Early Girls from our CSA on Sunday, by chopping the raw tomatoes and cooking them down, skins & seeds and all for about 3 hours. Tasty.

    Gorgeous panniers, btw. Who makes them?

    • Wonderful, Alice! I see you share my “affliction”. 🙂 The panniers are Berthoud panniers.

  • Nice to see canning with Weck jars in action. I had heard it was possible but always doubted. I’ll now try it!

  • Ronda

    I love the look of the Weck jars, but don’t love that the glass lid does not re-seal after opening. In other words, once you open the jar to enjoy the fruits of your labor (ha!), you’ve got a lid that just sits on top, but doesn’t actually seal or close. This has lead to spills and messes in my very full fridge.

    Or… am I just doing it wrong?

    • I would re-use the clamps to secure the lid if you don’t use the entire contents.

  • I’ve canned with Weck jars too, just a bit this year. I love how they look, and that there’s no BPA in the lids. I definitely use the clips in the fridge. It can be a pain to get them on without shredding the glass a bit though. I’ve got it pretty much down, but every once in a while it still happens. The extra 10 seconds to close the jar is becoming normal, finally, after 4 or 5 months of use.

  • Ronda

    Ah thanks. My first exposure to the Weck jars came from preserves I bought or were given to me. No clips. Since I’m not usually one to eat a whole jar of jam at once, it created the huge potential for mess.

    Planning a batch of katsup to gift. Will seek out the clips!


Jenny Oh

Jenny is a long-time contributor to Bay Area Bites, KQED’s popular food blog. She formerly worked as an Interactive Producer for the Science & Environment unit. Jenny graduated with honors from New York University’s Tisch School of the Arts Film and Television program and has worked for WNET/PBS, The Learning Channel, Sundance Channel, HBO and the University of California.

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