They’re lining up along the windowsills for a final ripening, covering the counters, piling up in bowls and buckets. The tomato harvest overtakes us while we’re busy with other late summer chores, and it can’t wait.

Even as we take tomato platters to every potluck, we keep an eye on winter and imagine how much a red sauce from these fruits, put up in jars, will brighten it. We’ll need lots of warm tomato soup, too, with sherry and crumbled bacon.

People without gardens are busy preserving tomatoes at this very moment, too. Even the best canned ones they can buy in the store lack that fresh, homegrown flavor, and friends often ask us for our extras to “put by.”

Pear-shaped paste tomatoes are the most efficient for this purpose. Thanks to their low moisture content, they take less time to cook down into a sauce. (I throw some into plastic bags whole, as well, to freeze and drop into soups later on.) But I also round up the big juicy beefsteaks and rich heirlooms such as Brandywine. Everything that looks like a tomato goes into those big simmering pots.

First, though, I put them through a fruit and vegetable strainer, a gadget big enough to handle lots of tomatoes quickly, with an investment of $50 or so. You clamp the strainer onto a counter or table and toss washed tomatoes, halved or quartered, into the hopper on top. Then you push them down with a plastic plunger while cranking a handle. Juice flows out one side into your stockpot, set on a strategically placed chair, while all the seeds and skins are extruded off to the other side. It’s easy and quick. Most brands, variously called Villaware, Victorio and Roma, look pretty much the same. If you grew up with Garden Way’s Squeezo — the all-stainless-steel Volvo of tomato strainers — it is probably still in your family. You can buy it online for about $195, and it is a good investment for a serious home canner.

Try straining those extra tomatoes and freezing the juice. (Barbara Damrosch/BARBARA DAMROSCH)

That I am not. I’m more a fresh-food-from-the-greenhouse, roots-from-the-root-cellar kind of cook. But tomato sauce, applesauce and grape syrup from deep purple grapes are essential for my winter well-being.

So let the tomatoes surge through the door until cold weather diminishes their flavor. It’s only the simmering-down that takes time, and I just have to check on that occasionally, making sure nothing sticks to the bottom. As the sauce thickens I lower the heat from a slow boil to a strong simmer, then stop when it looks thick enough to ladle over fusilli or vermicelli without puddling in the dish.

When done, the sauce is poured into clean jars and frozen, thus eliminating the extra step of pressure canning. Because I have a freezer anyway, for items like, say, a whole lamb or pig, I use the shelves on the door for storing these jars. I have learned to use straight-sided ones, because those with rounded shoulders break when their frozen contents expand upward, a mess you only make once.

Damrosch is a freelance writer and author of “The Garden Primer.”