Preserving the best of summer - canning (really freezing) fresh tomato puree.
If you frequent farmer’s markets or farm stands in the peak of summer season, it is common to see seconds tomatoes (also referred to as canning tomatoes) for sale. The last week of August into the first weeks of September is prime in New England for this. These tomatoes are sometimes bruised, have imperfections in shape, size or flesh, or are otherwise considered not ideal for full price sale. They are ideal, however, for processing into puree or chunky tomatoes to preserve. Given the reduced price point, it is also economical to buy in bulk. My local farm stand had 20 lb boxes of tomatoes for $20….and since they are usually $2.50 - $3 per pound, you can do the math. :)
There are MANY tomato varieties. Tomatoes for canning or making sauce are ideally paste tomatoes, such as Roma or San Marzano. If you have a garden and can have many of the same variety and specifically to use for preserving - these kinds of varietals are the best choice. If you are buying from farm stand or market, cherry tomatoes and large heirloom varietals are great for small batch sauce to eat right away. However, I wouldn’t recommend these types for larger scale preserving as you would need SO MANY cherrys and the heirlooms are quite watery and create a thin sauce. The midsized, every-day tomato are likely your best choice for balance of flavor and flesh to make puree (vs. water).
My choice for preserving tomatoes is to break them down, puree them, boil down again and put into the freezer. I happen to have a small space freezer in the garage, so there is room for this kind of endeavor. Whereas my pantry would not have room if I were to do the hot water bath method of preserving. Your local university cooperative extension will likely have food preservation workshops, at low or no cost, to learn more about methods and how-tos. The University of Rhode Island does a few every year, and have gone virtual for workshops for 2020.
This is messy and time consuming work. So even though the cost of the tomatoes is low - there’s time and energy to be spent too. In my opinion, the house smelling amazing and the taste of fresh tomatoes in February is well worth it.
Tools I use:
2 extra large stock pots
2 standard stock pots
Sharp knife
2 cutting board
Stand mixer with fruit & vegetable strainer attachment (this is KEY for me - and the attachment I use most)
Quart sized canning jars with plastic lids - my collection comes from my mom. There is a mix of wide-mouth jars (my preference, but I only have about 10 or so) and traditional size mouth jars.
1 or 2 cup liquid measuring cup
Silicone spatula
You’ll likely need the entire day to do this work - or at least three quarters of a day. How I do it:
I cut the tomatoes into chunks - either quartering them or cutting into eighths, depending on how large the fruit is. Use one of the standard size stock pots if you fill your extra large one, but leave the 2nd XL pot empty.
Start filling one of the extra large stock pots with the cut tomatoes. Once it is about ¼ to ½ way filled, turn medium heat under the pot. The tomatoes as they heat will naturally start to release juice and break down, so no need to add a thing.
Allow the tomatoes to simmer (NOT BOIL as they will stick to the bottom of your pan) for about 1 ½ to 2 hours. The pot should have lots of liquid, some skins that have separated from the fruit and the fruit itself.
Turn off heat and allow to cool. Given the large pot, this could take 2+ hours to be at a temperature that won’t scald you as you continue to work.
When cool enough to handle, set up the stand mixer with the puree attachment. Be sure your 2nd XL stock pot is nearby as you’ll add the puree to it.
With the stand mixer on low or medium low, start to add the cooled simmered tomatoes in batches. I use a liquid measuring cup to transfer from the pot to the puree.
Be careful to pay attention to the mixture of skins and seeds that comes out the end of the puree attachment as I have had many an instance of it falling into the bowl of puree. I also put the skin / seeds mixture through the puree attachment a second time before discarding as waste.
As the puree bowl fills, return it to the empty XL stock pot to re-simmer, using the empty standard stock pot for any excess.
Simmer the puree for about 1 ½ - 2 hours or to desired level of thickness.
Cool the puree before transferring to the canning jars for storage. I allow cooling overnight in the covered jars before adding to the freezer.
This year, I did this using 40 pounds of tomatoes and was able to get 17 quarts of puree. Already looking forward to the treat of being able to pull a jar or two out over the fall and winter.
You can use as you see fit - as you would any other canned puree. Over the course of the winter, I’ll share the soup, sauce, stew and chili recipes I use my stash in. So more to come. I have not experimented in making peeled tomatoes for storage or diced. Maybe that's next summer.
Until then…. Buen provecho!