This week, I made tomato purée during my annual squirreling-away-of-all-the-tomatoes ritual. In the fall or winter, I’ll transform this staple into pasta sauce or pizza sauce or tomato paste or add it to chana masala or minestrone soup or any other recipe calling for fresh tomatoes. Every year in late September or early October, I buy 20-pound cases of tomatoes to process and enjoy well after tomato season ends. So far, I’ve bought two cases and will buy a third this weekend.
Usually, I roast every last tomato (go here for instructions) but one night, while deciding between prepping and sleeping, I chopped up a few pounds of tomatoes, threw them into the slow cooker and chose sleep. By the morning, the tomatoes had softened and condensed. I ran them through my food mill, reduced the ensuing purée over low heat, stored it in a jar and froze it. So easy! I’m definitely adding this to my yearly ritual.
Which tomatoes work best?
Choose dense tomatoes such as plum tomatoes and avoid watery varieties such as heirlooms, which will cook down very slowly. The cases I buy are not plum but Early Girl dry-farmed tomatoes. The intense, sweet tomato taste adds so much flavor to dishes but I will look for a case of plum tomatoes next year for this purée.
Special-ish equipment
Slow cooker
I cooked a few batches of tomatoes in a 2-quart (8-cup) slow cooker. (Our Star Wars slow cooker is very small.) You can also slow cook tomatoes in an Instapot set to slow cooker mode.
Food mill
I love my food mill. It easily removes skins and seeds from cooked tomatoes (and other vegetables). I don’t even bother to core my tomatoes when prepping them—the food mill removes any tough parts. But you may not have a food mill or you may not mind tomato skins in your purée. You have a couple of options for processing tomatoes without a food mill.
If you don’t like skins in your tomato purée
- Blanch and peel the tomatoes. Core the tomatoes, score the bottoms with a shallow “X” and drop the tomatoes into a pot of boiling water until the skins begin to pull away (about 1 to 2 minutes). Immediately transfer the tomatoes to an ice bath—a large bowl filled with cold water and ice cubes. When the tomatoes are cool enough to handle, pull the skins off with your fingers. They should slip off easily.
- Cut the tomatoes in half. With a spoon, remove the seeds.
- Chop the tomatoes.
- After cooking the chopped tomatoes, purée them with an immersion blender, standard blender or food processor.
Dehydrate the skins in a food dehydrator or at a very low temperature in the oven and grind them up for homemade tomato powder, if desired.
If you don’t mind skins in your tomato purée
- Cut the tomatoes in half. With a spoon, remove the seeds.
- Chop the tomatoes.
- After cooking the chopped tomatoes, purée them with an immersion blender, standard blender or food processor.
Cooking down the tomato purée: Should you bother? If so, how?
After cooking the tomatoes, processing them and allowing them to cool, you can store them in the freezer and call it a productive day. If you intend to use the purée in soup, you’ll add less broth or water to your recipe if you use the purée as is—and you’ll conserve energy and your time.
On the other hand, reduced tomato purée will take up less space in the freezer and you already have your apron on. I’ll use the purée for thicker sauces and will need to reduce the purée eventually anyway, so I cook it down before freezing. (I freeze mine in wide-mouth glass jars. Go here for more info.)
Reduce in a pot
This works quickly and renders a wonderful, sweet flavor. The purée cooks down considerably in about an hour on medium-low temperature.
Reduce in a slow cooker
The tomato purée reduces very slowly in a slow cooker, even by slow cooker standards. These appliances do not do a great job at cooking down liquids and may not stay hot if you remove the lid in an attempt to speed things up.
If you choose the slow-cooker route, do not cook longer than about eight hours on low. Otherwise, your tomatoes may develop a bit of a burnt flavor.
I prefer the stove-top method but cooking tomatoes in your sleep has its benefits!
How the annual tomato ritual started
When we broke up with plastic in 2011, I had to figure out how to replace canned tomatoes. Cans are lined with epoxy (i.e., plastic) that contains industrial chemicals such as BPA. And although many food manufacturers plaster the claim “Now BPA-Free!” on their cans, the linings may contain something similar and just as bad.
I don’t know if I would have started roasting so many tomatoes had I not broken up with plastic. As a result, the tomatoes I eat now taste incredible. Make this tomato purée for taste alone!
Tomato Purée from Fresh Tomatoes
Equipment
- slow cooker
- food mill to remove tomato skins if desired
- immersion blender, blender or food processor if not using a food mill
Ingredients
- 3 pounds fresh tomatoes
Instructions
If using a food mill
- Wash and chop tomatoes into bite-size pieces. Cook in a slow cooker on low heat for 6 hours, until cooked and soft.
- Place the food mill over a large bowl and run the tomatoes through it. Store the purée in wide-mouth jars and freeze or cook down before storing.
If not using a food mill to remove the skins
- Blanch and peel the washed tomatoes. Core them, score the bottoms with a shallow "X" and gently put the tomatoes into a pot of boiling water until the skins begin to pull away (about 1 to 2 minutes). Immediately transfer the tomatoes to an ice bath—a large bowl filled with cold water and ice cubes. When the tomatoes are cool enough to handle, pull the skins off with your fingers. They should slip off easily.
- Cut the tomatoes in half. With a spoon, remove the seeds. Chop the tomatoes and cook in a slow cooker on low heat for 6 hours, until cooked and soft.
- Purée the tomatoes with an immersion blender, standard blender or food processor. Store the purée in wide-mouth jars and freeze or cook down before storing.
If not using a food mill and leaving the skins on
- Cut the tomatoes in half. With a spoon, remove the seeds. Chop the tomatoes and cook in a slow cooker on low heat for 6 hours, until cooked and soft.
- Purée the tomatoes with an immersion blender, standard blender or food processor. Store the purée in wide-mouth jars and freeze or cook down before storing.
To cook down the tomato purée
- Simmer the purée gently on medium-low heat for an hour or until it has reached your desired consistency. Stir often. You can also cook it down in the slow cooker at low heat for 8 hours. Avoid cooking it for longer than 8 hours. Cooking tomatoes for too long in a slow cooker can result in a burnt taste.
Nutrition
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I love your Start Wars slow cooker! My husband would be so jealous!!
I like to core and halve tomatoes, put them in a large freezer-safe container, and freeze them until the weather cools down. Once thawed, the skins and many of the seeds slip right off/out. The tomato water separates out too, but since it is quite flavorful, I cook it down together with the tomatoes, and then I can it up in glass jars, at a time when extra heat in the kitchen is welcome. I use a variety of types of canning jars, and while Weck are my favorites, because they only use a rubber gasket and glass, they are pricey. Tattler reusable plastic lids also work, as well as the bail-lid types such as Fido and Le Parfait.
In general, I try to only use the freezer as a way-station to more shelf-stable solutions.
I just love reading your newsletters Ann-Marie. I save them to read a second time, which is why I’m leaving a late reply.
My favorite parts of this entry on tomatoes are:
– and you already have your apron on. 🙂
– Dehydrate the skins in a food dehydrator or at a very low temperature in the oven and grind them up for homemade tomato powder
I like that you help people to use every part of the produce. Thanks for sharing all your great ideas!
Thank you for the kind words, Lija. I appreciate you taking the time to read the newsletters and highlight your favorite parts. I find it so fun to figure out how to use all the parts of produce 🙂
After making the purée can you just do the caning process if you don’t have much room in your freezer?