I harvested my garlic scapes today, along with a whole bunch of chives, and enough mint to get my mint patch under control. My problem is that I grow garlic on a mass scale, something like four hundred plants, so I end up with far more garlic scapes than any one family is likely to use, even in a family as extended as mine. The scapes do not dry well, becoming tough and fibrous, and though they last quite well if they are kept cool, they become dry and unusable long before I can use even a small portion of them. I looked to the internet for ideas on how to preserve them, but it was mostly useless. There were any number of recipes for garlic scape pesto, which can be frozen into ice cubes and thawed throughout the year, and I have made this kind of thing before, but I can only eat so much pesto.
So, I determined to see whether I could adapt the idea of the frozen pesto cubes, only without the pesto. I roughly chopped the scapes, put them in a blender with some olive oil, ground them into a paste, and put them into ice cube trays. This approach worked well, but I found that I was using a fair amount of olive oil to get the moisture content high enough for a smooth paste, so I tried adding a little water instead, and found that this was a much better option. The scapes pureed better, froze more solidly, and will probably last longer in the freezer. They do tend to stick in the ice cube trays a little, but some warm water on the back of the trays gets the cubes free quite quickly, and then they can be bagged and kept in the freezer until needed.
By the time I was finished experimenting, I had settled on proportions of something like two tablespoons of water for every quarter pound of roughly chopped scapes, but this will likely differ a little depending on how fresh and how moist your scapes are. My suggestion is just to add water in small increments until the paste is smooth, and to pour off any excess water that collects in the bowl. It should not take long to find proportions that work for you. Of course, if you do not have four hundred garlic scapes that need processing, and you are not interested in finding some just to make garlic scape ice cubes, you can always come over and sample mine sometime. I assure you, I have more than enough for everyone.