Yup, August is for Tomatoes! Most of this was sold through Hayshaker Farm.

When we’re in the height of tomato season, there’s always a bit of “tyranny of produce” happening in our house, as flats of long awaited tomatoes start to stack up on counters, chairs, chest freezer lids… you get the idea.

I’ve learned over the years to rotate which preserved foods to focus on year to year, as we often don’t finish up all of last year’s bounty by the following year. So one year I might make BBQ sauce and a lot of salsa. Another I might focus on tomato soup and simple canned tomatoes. Every year I make a few batches of roasted tomato sauce for the freezer.

And lately, every year I make a very concentrated batch of tomato paste, which I call Conserva – though technically, Conserva in Italian just means preserved. And according to Hank Shaw, who’s recipe I am documenting here, I’m really taking Conserva to the next level, which is ‘Strattu (short for estratto, which translates as extract).

In short, you take 20+ lbs of tomatoes and cook them down very slowly in an oven (in Italy, they do this outside on the rooftops) until its a very concentrated paste. What starts out as about 2 1/4 GALLONS of tomatoes ends up as about 3 1/2 cups of finished paste. About a 91% reduction. Assuming that about 40 tomatoes goes into 20 lbs of puree (my tomatoes are pretty big), that works out to about a tablespoon of this concentrate being the equivalent of a 6 oz tomato. In short, its the best tomato paste you’ve ever tasted, and an amazing umami bomb to add to most any soup or stew that calls for regular tomato paste.

I keep mine in the fridge. I’ve never had it get moldy, and I’ve sometimes kept it for way over a year. I occasionally gift it to friends. But I don’t think they really understand what a labor of love this is, or how panicked I start to get when I’m running low and its not tomato season yet. So mostly, I just hoard this for my own use.

Conserva - Concentrated Homemade Tomato Paste

  • Servings: 56 tablespoon servings
  • Difficulty: moderate
  • Print

The best tomato paste you've ever had, that will last for over a year in your refrigerator

You can make this with a standard hand crank food mill, and that’s what I’d used for years. But this year I finally dug out my Norpro Sauce Master. This piece of hardware claims to be able to strain fresh uncooked tomatoes, and I’ve never had it work well for that purpose, leaving WAY too much of the pulp in the waste bin. So I quit using it. However, if the tomatoes are heated and you run the waste product back through it a second time, it works beautifully, and strains out ALL of the tomato seeds, which my food mill isn’t able to do. I’ve finally found a use for this contraption!

Available on Amazon for about $60. Mine was a gift many years ago.

It’s a good idea to start this process at the beginning of the day, and when you’ll have a 3 day stretch of being home (perfect for our current never ending lock down livestyle)


  • 20 lbs of tomatoes, dead ripe. Paste is best here, but any tomato will work. It will just take longer to cook down
  • 10 or so tomato leaf sprigs
  • Salt – about 1/2 tsp
  • Large sauce pot – minimum 2 gallon, or work in batches
  • Several large roasting pans or 9 x 13 baking pans or an assortment of oven safe containers
  • Food mill of some sort, with fine screen for filtering out seeds and skins


  1. Core and cut your tomatoes into large chunks and place into your large sauce pot.
  2. Lightly salt your tomatoes (remember, what you add now will be very concentrated later – a light hand is called for. You can’t take it back out!)
  3. Heat tomatoes on low/medium heat until mixture JUST starts to bubble, giving it a few stirs to avoid tomatoes scorching on the bottom before much juice has been released. You don’t want an active boil here – just enough heat to soften tomatoes and loosen skins – I’d guess about 180 if you were using a thermometer. Mixture will heat faster if you have a lid on your pot.
  4. Turn off heat and let mixture sit for 30 minutes.
  5. Preheat oven to 250 degrees.
  6. Run tomato mixture through a “sauce maker” or food mill on finest screen size, to remove skins and seeds (if you end up with a few seeds in the finished product, its not the end of the world).
  7. Pour finished tomato pulp into roasting pans or whatever oven proof containers you have on hand. I happen to have a couple of shallow hotel pans, that worked beautifully for this, but I’ve used roasting pans and baking dishes in the past.
  8. Add a few tomato leaf sprigs to each container of pulp. It’s OK. It’s traditional, and it won’t hurt you. But if this freaks you out, just leave them out.
  9. Every few hours, stir the sauce. It should NEVER boil. You’re trying to preserve all the wonderful flavor enzymes that would be lost if the sauce was overheated.
  10. After 5 hours, remove tomato leaf sprigs and reduce oven temperature to 200.
  11. Continue to bake, stirring about every hour, until you are ready to go to bed. Depending on how early you started and how large your containers are, you might be able to consolidate your pulp down to one pan by the end of the day. Turn off the oven, (leave a note so someone doesn’t turn it back on with your tomato paste still in there) and go to bed. It will be fine in there. It’s dried out enough and is acidic enough that it’s not going to grow anything nasty overnight.
  12. In the morning, give everything a stir and turn your oven back on to 200 and continue baking, stirring every hour or so. Continue to consolidate into one container if you haven’t already done so.
  13. Most of the way through day 2, your sauce should be greatly reduced, and you should start to be able to drag a line through it with a spatula that doesn’t immediately flow back in. You’re doing great! Turn off your oven again and go to bed, patting yourself on the back for all your work so far.
  14. On day 3, again, stir and turn your oven back on. Continue to stir every hour (this hourly check in is more important as the paste becomes more concentrated). Eventually, you’ll be able to basically fold it over on itself and it will stay put where you leave it. How far should you go? It’s hard to know when to stop. But I find that as the paste enters its final stages, you have to watch it more carefully, and eventually, I start worrying I’m going to dry it out TOO much and accidentally burn it. So I stop. It should look like brick red sticky goodness and taste like the best tomato paste you’ve ever tasted when you decide to call it good.
  15. Lightly coat a wide mouth quart sized canning jar, or a series of pints and half pints and quarter pints, with a nice olive oil. Scrape your finished paste into the clean oiled jars, trying not to trap any large air bubbles, and top with olive oil if you wish. Add a lid and store in the fridge.
  16. Theoretically, this paste is shelf stable (that’s how they treat it in Italy). But I keep it in the fridge for good measure. My fridge is about half condiment jars anyway, so what’s a few more?

What do you do if you need to use the oven for something else during this 3 day bake? Simply remove the paste, bake what you need to bake, and then lower the oven temp back to 200 and put your paste back in the oven.

Note: if you had a dehydrator big enough, theoretically, you could do this in a food dehydrator. In Italy, they basically use their hot summer rooftops as outdoor dehydrators instead of using their ovens. I’ve not tried it, but it should work. I’d keep the temp at 135 or higher.

© 2020 Miles Away Farm, where we’re miles away from discovering all of the ways to preserve tomatoes, but we’re game to try!