Conserve excess tomatoes with an easy, homemade tomato paste that can be made on the stove top, in your oven, or in a slow cooker.
Well, I'm posting this a lot later than I would have liked. You see, this year I was able to get up a new fence around the area where I usually plant things, and once again planted a lovely organic vegetable garden. I wanted to write a couple of posts about different ways to conserve and use excess vegetables from your garden at a time when everyone would be looking for ways to use theirs, but life got in the way. I figured now is as good a time as any. Better late than never, right?
Why make your own Tomato Paste?
Making tomato paste is one of my favorite ways to use and conserve excess tomatoes. Tomato paste is very concentrated, so you can easily reduce a lot of tomatoes into a small space. You can then freeze it, can it, or make it into fermented ketchup. I'll be sharing how to do that next time!
Making the process quick and easy!
I used to peel all of the tomatoes before making tomato sauce and tomato paste, but I found it took a lot longer than the way I do it now. Now, I blend the tomatoes in the blender and later strain out the seeds and skin. You can save some time cooking down the sauce by removing the seed sections before blending the tomato pieces.
Should you leave the skin and peels while cooking?
Some people begin cooking the sauce with the peels and seeds still in the sauce and then later strain them out. The idea is that the pectin in the tomato skins will be released into the sauce to help thicken it. I find that it can make the sauce bitter if you don't remove them before cooking. This, of course, may depend on your particular tomato variety. I prefer flavor to thickness, but you can experiment with your tomatoes to decide which method is best for you!
Making a thick tomato paste
Making tomato paste is simple. All we're doing is making a basic tomato sauce by cooking a tomato purée and slowly reducing it further to make it more concentrated. We do that by evaporating out even more of the water.
There are several ways to efficiently reduce the water content of your tomato paste. I normally slowly cook the tomato sauce in a pan on the stove over low heat, but you can also do so in a slow cooker with the top off, or even by spreading out the tomato sauce onto baking pans or dehydrating trays (in which case you'd thicken the sauce in either the oven or a food dehydrator). The idea is to heat the sauce over low heat, evaporating away the water, until you reach the consistency that you like.
While I normally prefer making the tomato paste in a pan on the stovetop, keep in mind that as the sauce thickens, it's also more likely to burn. That's why cooking at low temperatures, stirring, and keeping a constant eye on things, especially towards the end of the process, are key! If you won't be able to watch it as closely, using a slow cooker (lowering it to low heat or “keep warm” setting when it's getting thicker) or an oven on its lowest temperature and convection setting (fan) may be better options. The process of making tomato paste may be slower using those methods, but your paste won't need as much attention throughout. Using those options isn't foolproof, though. You'll still want to be careful when it gets thick, to avoid burning!
Which tomatoes make the best tomato paste?
While you can use any of the tomatoes in your garden for making tomato sauce or tomato paste, certain tomato types are better than others. Tomatoes like Roma tomatoes, and other so-called paste tomatoes, have more flesh and fewer seeds, so they take less time to cook down to a thick sauce and make a nice, hearty, thick sauce. Most of the best varieties for sauces and pastes are tall and elongated, rather than short and wide.
How to store homemade tomato paste
Most of the time I freeze my homemade tomato paste in perfectly cube-shaped ice cube trays like the ones I used for freezing my homemade baby food and smoothie cubes, homemade pumpkin puree, or homemade pesto (my son's favorite!). The advantage to using perfectly cube-shaped ice cube trays is that the frozen tomato paste cubes fit together perfectly in ziplock bags without wasting any space. You can then label your bags and sort through them easily to find what you need from the freezer.
I don't have a lot of experience with canning, but I've read that it is possible to can homemade tomato sauce and tomato paste. You may need to add some citric acid (which can be in the form of lemon juice) to your paste if it isn't concentrated enough. (This is to prevent the growth of the bacteria that cause botulism.)
Watch how I make Tomato Paste
Easy homemade tomato paste recipe
- 8 lbs. tomatoes
- 1.5 tbsp extra virgin olive oil
- Rinse the tomatoes well, remove the stems, and cut into chunks.
- Fill a blender jar with the tomato chunks and blend until the tomatoes have all reduced into a sauce.
- Place a stainless steel strainer over a large pot on the stove (or over your slow cooker pot), and pour the tomato sauce into the strainer. Use a stainless steel spoon or a spatula to press the tomato sauce through the strainer into the pot below. In this step, we are straining out the skin and seeds of the tomatoes.The best way to get all of the tomato goodness out is to scrape the seeds and skins against the strainer. You can watch how I do that in the video above.
- Repeat with the remaining tomatoes. Some people like to add in red peppers and other vegetables to their tomato paste. If you want to add in other vegetables, now is the time to do it. I, personally, prefer to keep things simple and just use tomatoes. I add in other vegetables, spices, and seasonings, as needed, depending on the recipe that I'm using the tomato paste in. That said, I do like to add a dash of olive oil to the tomato paste as it reduces on the stove.
- Heat the sauce over low heat until simmering, stirring every once in a while and checking on the consistency. As the water evaporates away, the sauce will continue to thicken. As is starts to get thicker, you will want to turn the heat down lower and check on the tomato paste more often because it gets more likely to burn as it gets thicker and has less water. When using a slow cooker on low, you can leave the tomato paste unattended for longer periods of time, but as it starts to thicken, you will also need to check on it more often to prevent it from burning. (Make sure to leave the lid off the slow cooker or the water won't evaporate away.)
- To give the tomato paste a more caramelized flavor, and reduce it even further, you can bake it on clean baking pans on low heat in the oven. Scrape the tomato paste from the bottom of the tray with a spatula, stirring it into the rest as you frequently check on the consistency. Some people do the entire process of making the tomato paste in the oven, but I prefer to reduce it to a sauce on the stove first.
- Once you've achieved the desired consistency, the tomato paste is ready to be used in recipes, or ready to be stored. I usually freeze excess tomato paste, but it is possible to can it instead. If you do decide to can it, from what I understand, you should add some citric acid (which can be in the form of a bit of lemon juice) to the paste before canning. If it's concentrated enough, though, it may not need it.