Thickening Tomato Sauce
Paste has it place. I use it but not with fresh tomatoes.
You can also cut your tomatoes the day before you need them, place them in a china cap, collander or chinoise and drain them into a bowl over night. This will also remove a good deal of moisture. :)
Canned tomatoes can be surprisingly good or plain awful. It sounds like you're using whole tomatoes, a good start. But what are they packed in? As a generalization, puree is better than juice which is better than water. Read your ingredients to find out what you've got. This is probably one of your problems with runniness.
Also look at additives. There are usually two: Salt and Calcium Chloride. Salt offers some flavor and preservative effects. Calcium Chloride has a very salty flavor, is a firming agent as well. Purists avoid the calcium chloride. I have a sodium restricted diet so I actually use a brand with only tomatoes and calcium chloride which works well for me.
I do have to give props to Pomi brand tomatoes whose aseptic packages list but one ingredient: Tomatoes. I used Pomi exclusively when I lived in Germany and was very happy with the product. They're quite a bit more expensive here in Europe.
Muir Glen is a respected quality brand of canned tomatoes in the US and can be had at reasonable prices on sale, but is otherwise expensive in my book. I stock up at sales.
Thickening may not be what you want to do really. It depends on what you want to do with it.
The more you cook a tomato sauce, the less tomato impact it tends to have. There are times this is what you want such as a bolognese with a more blended meaty flavor.
But for pizza or marinara, a fresher tomato taste is generally desirable.
Here are some ideas you may find useful.
Drain your tomatoes and reserve the liquid. Lightly crush the tomatoes and drain again adding that liquid to the reserved liquid.
Mill your tomatoes as normal. You could add in the amount of liquid you want for the sauce so you have the fresh taste of a less cooked sauce. Or you might try reducing the liquid and blending that into the solids. I'm not sure where the flavor profile would end up though.
me eat it all the time
There is good advise here already.
Here are my observations:
Choose quality tomatoes.
as already stated, simmer, simmer then simmer longer.
Regular home cornstarch will not hold too long in an acidic environment like tomato sauce.
Add lemon juice, the added acid will help the natural pectin to firm up. (citric acid is better if you can find some).
If all else fails, add tomato paste.
The tomatoes were canned in juice. I'm not sure about the additivies, but they didn't taste salty to begin with. I don't have any cans lying around currently either. When I made the sauce I sent the whole tomatoes through the mill, and then combined all the ingredients (pulp and jucie from tomatoes, and extra juice from the can) to the pot. It seems that my main problem may be the adding of the juice from the can. That would make sense for the runniness of the sauce.
The flavor profile on the sauce tastes good, it's just really runny (due to the extra juice?) I'm not trying to get the sauce extremely thick, but less watery than it currently is. I'm trying to stay on the cheaper side, due to a college budget, but I also love good food.
Phatch: Do you find the flavor of sauce made with fresh tomatoes leaps and bounds above canned tomatoes? If so, is it best to just wait until the summer, go to some farmer's markets and make a huge batch then? My only concern is that fresh tomatoes can be pretty costly.
Well, I was just here looking at what other people did to thicken tomato sauce. Here's exactly what I did:
1. I picked about 2 handfuls of cherry-tomato (i'm not positive what kind of tomato it is) sized tomatoes, washed them, and cut off the stems.
2. I cooked (not really carmalize) diced onions of half a medium-large onion with good amount of olive oil. (BTW, its cooking the whole time while you're preparing the next item to add. no need to wait to turn on the fire.)
3. add tomatoes and 3-5 tablespoons of bought tomato sauce. (I don't know about the results if you skit it. It was just around the house and I said, "why not?" and it is organic and everything. trader joes
4. add rosemary or any herb bunch tied by string (my younger sister hates flecks of herbs in her food)
5. I added a small handful of chopped (or minced) cilantro. (i prefer the flavor to parsley)
(BTW, its cooking the whole time while you're preparing the next item to add. no need to wait to turn on the fire.)
6. After cooking awhile (10 min about) add squeeze of lemon juice and pinch of flour.
7. cook for 20-30 more min.
DONE WITH THE DELICIOUS SAUCE!