I have a garden every year and would prefer to use my own tomatoes for all my cooking. I can them and make sauces, but haven't found a good recipe that describes the technique for tomato paste. I need it to be thick like you buy at the store - I use this for sauce dishes, etc that I don't like to be too runny. How would a home cook go about making tomato paste?
Tomato paste is just tomatoes with the water removed, essentially. I'd slice the tomatoes in half and roast them (cut side up) at 350 degrees F for an hour (this will concentrate the flavour nicely and you can add s&p/olive oil/herbs/garlic if you want). Then mash them through a sieve or food mill to get a smooth consistency. Then put that tomato puree in a pot and just boil them down until it's as thick as you want. As it gets thicker, you'll need to stir it regularly to prevent it sticking to the bottom of the pot and burning.
I worked in a restaurant that made its own tomato paste at the end of every summer. Each week we would purchase 14 cases of vine rippened tomatoes picked in the morning from the farmer at the farmers market. Each day we would process two cases through the William Sonoma Tomato Press, add a couple table spoons olive oil and slowly simmer until the water has evaporated and the tomatoes are now a paste. We would just freeze the result and have homemade tomato paste through the winter.
I haven't tried this, so look at it as a thought experiment.
I'd take a tomato puree and cook it down to thicken somewhat, then spread it in a shallow sheet pan and cook it slowly in the oven at maybe 250-275F. I'd sort of stir/turn/re-spread it every 5 minutes to start, then do it more frequently as things start to thicken up. I'm totally guessing on the times, though.
The idea is to get as much moisture gone as possible without risking browning the tomato paste too much. The sheet pan gives you lots of surface area so you clear off a lot of water quickly, and makes it easy to handle. Low oven temps reduce the risk of burning.
As Italian I prepare my Tomatoes sauce every year, here are the steps.
Choose good pear like tomatoes, in Italy we have the San Marzano's tomatoes that have just a little bit of water (are the best IMHO).
You cut them and then you mesh them with vegetable mill or a mixer.
Be aware, here you have the greatest secret ever.
Take an old, clean cotton made cushion cover (or just a cotton bag), fill it with your sauce and hang it on a broom handle between two chairs (keep a container under the bag to avoid to loose water)
Keep it some hours till the sauce will loose all the water (you can help pushing with your hands).
Cook the sauce with just basil (no salt, never!)
Then you can sterilize the jar, but this may be another question ;-)
This is how I usually get a nice thick sauce home :
- Blanch the tomatoes and peel off the skin
- Mash the tomatoes into a puree (Either squish them using a wooden spoon, or use a blender, depending on the recipe you want to use it in. For eg., I sometimes like a good, smooth, blended sause for a sphagetti dish, but prefer a roughly mashed-up pulpy sauce for some vegetable curries)
- Put it on stove-top and bring to boil on a low flame. Stir occasionally to avoid burning.
- I also add sugar and salt at this point and continue to boil. (Seasoning is optional of course)
- Take cornflour in a small bowl and mix with a bit of water to make a smooth paste.
- Add the corn paste slowly to the boiling puree, keep stirring to avoid lumps. Gradually the puree thickens. The quantity of cornpaste depends on how much tomato puree you have, and how thick you want your sauce to get. You can try making a paste with two teaspoons of cornflour, but only add a little of it at a time.Continue adding till you get the right consistency.
- Once the paste reaches the desired consistency you can take it off the stove top and use it in recipes.