In recent years, my daughter (the resident tomato fanatic) has grown to understand that tomatoes from the farmers' market - fresh, local, vine-ripe, and in-season - are a garden treat unlike any other. In California, we could get wonderful tomatoes most of the year, fairly acceptable ones the rest of the time. In Michigan, she has come to scorn what she calls "tomatoes in training" (our son appreciates the acronym more than he does any tomato) and has told me not to bother buying them from the grocery store, preferring to wait for the market season. This year we got to try a wide variety of heirlooms, from bright yellow to funny striped ones, and it was fun to compare the flavors.
Tomatoes should be kept at room temperature - a mildly green one will even ripen nicely on a sunny countertop or windowsill - but they're quite delicate and need to be eaten quickly. Refrigerating them is not worthwhile - they lose too much flavor.
This year I planted Roma tomatoes from seed, starting them under lights in the basement (I'm sure my neighbors thought I was growing something else down there, judging by the constant glow emanating from the window wells!) and planting 6 of them along the east-facing wall of our house. I wondered whether there would be enough sun there, but I'd run out of containers and space in my raised beds. My worries were unfounded, though, and I've been harvesting a small bowlful daily - enough for my daughter to eat "as is" with plenty left over for salads and sauce.
While I would need to plant a lot more to make enough sauce to last through the winter, I've managed to freeze quite a few quarts of it. Canning still seems a bit beyond my schedule, although it's something I hope to learn in the future, and freezing is a great way to preserve vegetables. I know exactly what is in my sauce - tomatoes! - and don't have to think about whether the can liner is toxic, whether there are additives/preservatives, etc.
The one piece of equipment you'll need to make sauce from fresh tomatoes is a food mill, which pushes the sauce through while straining out seeds and pulp. It's a great investment for making applesauce, mashed potatoes, and baby food as well!
Washing and cutting the tomatoes into large chunks is all the preparation required for homemade sauce. During the week, any tomatoes that seem near spoiling or any of the harvest I know we won't get through simply gets washed, cut into large chunks, and placed in a quart container in the freezer.
Place the chopped tomatoes (frozen or fresh) in a saucepan, turn the heat to medium, and cover the pot loosely. Once the tomatoes on the bottom start to turn to sauce, turn the heat to medium low, uncover the pot, and stir occasionally. The sauce is done when all the chunks have broken down into a liquid with seeds and skins in it. At this point, you can let the sauce simmer for 10-15 m to concentrate it a bit, or you can simmer it longer, until most of the water has evaporated - this will give you tomato puree.
Turn off the heat and let the sauce stand until it cools to room temperature. Put it through the food mill, pour it into jars, and refrigerate. Tightly covered, the sauce will last up to 2 weeks in the fridge. Once it's chilled, you can freeze it for up to 6 months.
The amount of sauce you end up with varies based on the variety of tomato you use, but in general, a quart container of coarsely chopped tomatoes will yield about a pint (16 oz, 2 c) of sauce.