At this point, however, the work was just beginning. His plan for storing the basil over the winter was to blend it up with a bit of olive oil to make a slurry, which could then be measured out into ice-cube trays in one-tablespoon units that could be doled out as needed in our recipes. His usual preferred tool for making pesto and other sauces of this kind is our Magic Bullet blender (a Freecycle find that turned out to be surprisingly useful), but with such a huge volume of leaves to process, he decided to give the full-sized blender a try. The results confirmed that for this purpose, the Magic Bullet is indeed the better tool. The blender sort of mushed up the leaves without really grinding them, and getting the half-crushed contents out proved to be a huge hassle. So he decided he'd have to use the Magic Bullet after all—but the problem there was that it only has a capacity of about 12 ounces, and we had a couple of gallons of basil leaves to process. After about an hour more of alternately packing, grinding, and swearing, Brian had only made it through a fraction of the pile, and the motor of the Magic Bullet was starting to emit a burning smell.
With both Brian and the blender on the verge of a breakdown, I proposed finding some other way to preserve the basil—or at least store the leaves overnight and deal with them in the morning. A quick search on "how to preserve basil" turned up this Wikihow article, which provided several options for "short-term refrigerator storage." Since we'd already stripped all the leaves from the stems, only one of them was practical: packing them into a zip-top bag and tucking it in the fridge, to be dealt with in the morning. However, the article also mentioned several other ways of preserving basil over the long term, some of which looked intriguing. Considering what a hassle our usual blend-with-oil method was turning out to be, and considering also how long it would take to convert such a large volume of basil slush into frozen cubes, any method that didn't involve the blender looked very appealing indeed. In fact, I thought perhaps we could look on this basil bother as an opportunity to try out a whole bunch of different methods for storing a whole bunch of basil, and see which one worked the best over the long term.
Of the various methods outlined in the article, we decided to try these three:
1) Freezing whole leaves. The Wikihow article says you can simply spread them out on a tray and freeze them, but we'd tried that before and found they were mushy and not very flavorful when thawed. However, a second article from About.com Food Preservation explained that you can fix this by blanching the basil before freezing it, killing off the enzymes that cause it to degrade. Their instructions for blanching involved dipping a whole bunch of basil in boiling water, then in ice water. We couldn't do this since we'd already stripped the leaves off the stems, so Brian instead came up with what he called the "butterfly method": drop a handful of leaves into the water, swish them around with a sieve, then scoop them back out and dunk them into the ice water. This left them wilted but still green. Then he spread them out in a freezer bag, forming a layer as nearly flat as possible, and popped it in the freezer. The idea is that individual clumps of leaves can be broken off as needed, leaving the rest of the mass intact.
3) Packing in oil. Again, a very simple method with no freezing, but it does use up quite a lot of expensive olive oil. We went with a jar again, loading it up with leaves, sprinkling in salt, and then filling the whole thing up with olive oil. Wikihow promises that leaves packed in this way and stored in the fridge "will remain in great condition for use over the coming months" and can be used just like fresh basil in any recipe. The basil-infused olive oil can be used too, so it doesn't go to waste, but you'd presumably have to use it in a recipe that's very heavy on both oil and basil. Maybe processing the basil and oil together into pesto—in small batches—is the way to go.
In addition to these, we have about thirty of our traditional basil-and-oil cubes in the freezer, and about another fifteen cubes' worth in the fridge waiting to be measured out. Brian actually mulched up quite a large volume of basil on Friday night before he packed it in, so we now have more basil cubes than we usually do when starting the winter, plus all the other basil we've preserved in alternative ways.
Only time will tell how well each different batch of preserved basil holds up, but one thing we've definitely learned from this experience is that we needn't plant nearly as much of it next year. Our carpet-bomb sowing method produces such a massive yield per square that we could reduce the area planted from four square feet to two and still have plenty of basil to use all year long.
Now, it's on to figuring out how to deal with the massive quantity of Sun Gold tomatoes our plants are still producing—but that's a subject for another day.