First, I want to admit something: Making sauce from fresh summer tomatoes has long been an insecurity of mine, despite years of cooking experience, including working as a sous chef in a Tuscan restaurant in New York and living and working on farms in Italy for extended periods, elbows deep in fresh-picked tomatoes and the sauce we made from them.

The reason why: there are two primary goals when making fresh tomato sauce, and they’re at odds with each other:

• First, the sauce should taste like it was made from fresh tomatoes, which means it should have the bright, fruity aroma and flavor of uncooked (or barely cooked) fruit. If we don’t have this, we might as well throw in the towel and stick with canned tomatoes 365 days of the year.
• Second, the sauce should have a good sauce-like consistency and have deep, sweet notes, which means cooking off much of the tomatoes’ natural water content and caramelizing the fruit’s natural sugars. Otherwise it’s going to be too thin and tart.

The trouble is that retaining the tomatoes’ fresh flavor means minimal cooking, while getting rid of the excess water content and caramelizing sugars means extended cooking. Everyone has a different solution to this dilemma. Some discard the watery seed-jelly and cook only the tomato pulp, which I refuse to do because the seed jelly has way too much flavor to waste. Others settle for a minimally cooked sauce that just heats for about 25-30 minutes, but I find this to be a compromise that fails to deliver the deep, sweet flavors we want. Another approach is to divide the sauce into two parts, one long-cooked, one quick-cooked, and then blend them back together.

Of those approaches, the divide-and-conquer concept has always made the most sense to me, but I’d never settled on exactly how to do it. To figure it out, I started with the first obvious question: What kind of tomato should we use?

You Say Tomato, I Say, Which One?

The first rule of making tomato sauce from fresh tomatoes is to do it in the peak of summer, when tomatoes are not only at their absolute best, but also their absolute cheapest. In the winter, when the only tomatoes available are ghostly versions of their in-season selves, it often makes more sense to use canned: canned tomatoes tend to be made with fruit that’s more ripe than anything we can hope to get out of season, and they’re generally cheaper, especially when you account for the amount of water weight that fresh ones have to shed before they become sauce.

But there’s still the question of which fresh tomatoes to use when they’re at their peak. The general wisdom is to use pulpy “paste” tomatoes (i.e. plums), which are less watery. Those guys yield more sauce per pound of fruit and require a shorter cooking time to get rid of the liquid, which helps retain some of that fresh tomato flavor.

But are plum tomatoes really the best way to go? And does it matter which kind of plum tomato you use? I bought four different types of tomato at the farmers market: three different varieties of plum tomato and then common beefsteaks, which are basically never recommended for sauce due to their juiciness. There are far more varieties of tomato than this, but it isn’t practical to test them all, and, frankly, most other varieties, such as most heirlooms, cost a premium—making them a prohibitively expensive option for sauce.

And these are the beefsteaks. Tanta acqua! Clearly, after all this water cooks off, there’s not going to be much sauce left, which is why it doesn’t make a lot of sense to make sauce from these kinds of tomatoes, unless you like paying hard-earned cash to humidify the air in your home with tomato vapor.

But, since I’d already started, I took the beefsteaks to their completion, straining out the skins and seeds and cooking the purée down. I did the same for all four types of the tomatoes, and was surprised at how drastic their flavor differences were.

• The San Marzanos made a purée that was bright and tart and not too sweet.
• The Amish Pastes produced a purée that was sweet, mild, slightly tart, and fruity.
• The Romas were sweet and floral, but not very tart.
• The beefsteaks had a great balance between sweetness and tartness.

Alone, each had its strengths, one more tart, one more sweet, one fruitier, another more fragrant. But as I tasted them all, what I realized was I didn’t want any one of these tomatoes in my sauce: I wanted all of them. Tasting then one by one, each was good, but combining them into a single spoonful made the whole thing pop.

To be clear, the flavors of my tomatoes are particular to the ones I bought: You may buy San Marzanos that are sweeter and less tart, and Romas that are tart but not sweet. It depends not only on the variety, but also where they were grown and other specific environmental conditions. It’s hard to predict with certainty the exact flavor profile and balance of sweetness and tartness any given tomato will deliver, so the best way to arrive at a balanced sauce is to combine multiple types.

The majority of the tomatoes should be pasty plums—ideally a variety of types if you can find them—because they’re more cost-effective. But I’m willing to add a little extra water from a small portion of beefsteaks or other juicy tomatoes if it means I can get a little bit of their flavor in the mix.

http://www.seriouseats.com/2014/08/how-to-make-the-best-fresh-tomato-sauce-summer-spaghetti-sauce-which-tomatoes-to-use.html

Prepping the Tomatoes

Once I’d settled on using a mix of tomatoes, the next step was deciding on how to prep them. Most folks agree that an abundance of skin or seeds in a tomato sauce is not a good thing, but there’s more than one way to remove that stuff from a sauce.

Some recipes call for discarding the seeds altogether, but as I’ve already mentioned, I like the flavor of the jelly the seeds are suspended in too much to do that—in fact, it has a tartness that I think is essential to creating what will ultimately be a sauce that has a good balance of sweet and tart flavors.

As for the skins, one option is to score the tomatoes, quickly blanch them and then peel off their skins. This is fine for small quantities of sauce, but I felt strongly that I wanted to select a method that would work for large batches—we are doing this in peak tomato season so we might as well make a lot, and peeling each tomato individually isn’t practical.

The method I know best is one I used when working on farms in Italy where we would make vats of sauce each week in the peak of summer: The tomatoes are cut into chunks, cores, skins, stems, seeds, and all (absolutely no need to exclude anything except the odd bad spots you may find), dumped into a pot, and set over high heat until they dump their juices and come to a boil.*

*Yet another method involves baking the tomatoes first at low heat to drive off some of their water, and only then to quickly cook them into a sauce; the reason for this has to do with how temperature affects enzyme activity and flavor, but for large quantities of sauce I also find this method impractical.