The garden is in full grow mode right now and we’re up to our ears in leafy greens. Some, like lettuce, can’t be held over for the winter, but other, more hardy greens can be. Kale, spinach, and mustard greens can be frozen, canned, or dehydrated. Although canning is usually preferable to freezing, in this case, one would have to pressure can the greens for an hour and a half to get a shelf stable, if unappetizing result (as the Doris and Jilly Cook blog demonstrate).
In all cases, it is best to harvest in the morning, before the sun begins to wilt the greens. They should be healthy greens that are not bolting (although you can taste-test some bolting ones to see if they’re bitter, and if not they’re fine to use). I leave the best-looking, slowest bolting plants in the ground to give me seeds for next year.
The next step is to clean and process the greens. I work in segments, processing about what would fit in a bread box in each batch. I set them all on the counter near the sink, chop off any thick stems or ribs and rinse the leaves in a sink full of water. I let them all sit in the water while I prepare the rest of the batch and then gently agitate the whole thing to let dirt and other bits drop out. Then I pull out the batch and let it drain in a colander in the next sink. No need for a salad spinner because they’ll either be getting blanched in hot water or set in a dehydrator.
Unfortunately, we can’t just toss these greens in the freezer: we have to neutralize an enzyme that would otherwise breakdown the leaves. While washing the greens, I heated water in my biggest pot, covered, until boiling. I did about three gallons — the more water heated, the better it retains its heat when the leaves are added. I turn down the heat once boiling, but before the next step, I crank the heat again to bring back the rolling boil. I also prepare a large bowl with ice water and set it near the stove.
Once a batch is ready, I dump the whole thing into the water bath. I use tongs to agitate the greens until they’re all underwater, toss the lid on and set a timer for 3 min. I stir it once or twice during this time. Once the time is up, I use a strainer to remove the greens and put them into ice water to stop the cooking process. I leave them in the bath until they are cool before putting them in another colander to drain. To get rid of excess water, I packed the greens a bit at a time into my potato ricer set on the smallest hole setting. This works like a press and squeezes out excess water before I plop it into a freezer container.
Some people freeze them on cookie sheets and then, once frozen, plop them into bags. Others put them in bags and squish all the air out, freezing them as flat packages. We use reusable quart and pint containers. They are more likely to get freezer burn, but because we just put them in soups, it isn’t a big deal.
Then I freeze them. If you can, clear out a space in your freezer so each container has lots of air around it to allow for quicker freezing (i.e., don’t stack all the bags on top of one another until they’re frozen). And don’t forget to label them with a name and date or you will forget when your freezer is full come November.
The downside of dehydrating is that the plants lose their cellular integrity, but the good part is that you end up with a shelf-stable powder that can enhance pasta dough or soups later in the year.
The process starts out similar to freezing but instead of blanching the greens in boiling water, they get spread out on dehydrator racks after washing and draining. Don’t overload the racks. Better to spread them out thinly on twice as many racks as thickly on fewer. These racks can then be rested above the boiling water in a large pot (if your pot is large enough) to steam for three to five minutes — until they’re a deep green. Be careful not to melt your racks. The racks get put on the dehydrator and set to 110°F, although I found I had to turn it up to 135°F to get them finished. Once they’re totally dry and crumbly, remove the leaves and crunch them down into an airtight container. Toss in some desiccant packets if you have any.