Like canning, pickling is all about controlling the forces of spoilage, living things like microbes especially, but also non-living things like enzymes. Both can be inhibited or destroyed in a variety of ways. Salt in high enough concentrations is hell on fungi, molds and bacteria, though not quite so good on enzymes. Likewise high doses of sugar. Acid is an excellent bug killer and enzyme deactivator, and then of course there’s heat, which will pretty much obliterate anything you want, provided the temperature is high enough and sustained long enough.
Any single strategy alone will get you where you want to go, at least in theory. But all-salt preserving leaves food pretty darn’ bear unpalatable. All-sugar is better, but outside of fruit preserving is of limited use. All-acid puckers the mouth something fierce, and all-heat makes food not only dry, it destroys much of what you wanted to preserve in the first place.
Nope, good preserving demands a subtle approach. Which is to say, a combination of strategies. A little of this, a little of that, the cumulative effect being a multi-layered killing zone inside of which no bug or enzyme can survive. Such is this week’ recipe which does indeed makes use of all four of these strategies: salt, sugar, acid and heat (interestingly, applied in doses over the course of several days). For us, the result is a refreshing counterpoint to a crisp summer salad. For the bugs, a micro-version of Hamburger Hill.