Like all the best ideas, I can't remember my exact train of thought with this one. Following some rather wayward googling, I came across the idea of the pickled lime. Or rather re-encountered the idea of pickled limes as, like the author of this article, my very first encounter was through reading Little Women. I was similarly baffled by their obsession but on thinking it through again, what could be more delicious by something wincingly sour, salty and limey. Tangfastics won't have anything on pickled limes.
Pickled limes are meant to have been popular in the Boston-area in the Little Women-era (mid 19th century? bit rubbish about eras etc. Later than 'days of yore', not quite 'modern-day').
A recipe was slightly harder to locate. After trying to weed out the recipes for an Indian-style lime pickle and trawling through quite a few broken links, there were few options. The method suggested by Bee Wilson in her article - put in jar with one tablespoon of salt per cup of water - seemed a little simple. But here goes... In case you were wondering, exactly thirteen limes fit in a large kilner jar. Turned out I had bought exactly thirteen limes and will henceforth be entering all "guess the sweets in the jar" competitions I encounter (likely none).
It also sounds has a Vietnamese counterpart called Chanh Muoi - detailed here. In this description and in quite a few others having read up afterwards (see the mistake there... afterwards), it seems that you can put a deep cross-slit in the limes and rub salt directly into the flesh to speed up the process. Alas, I didn't.
I then added a cup of water, followed by the requisite salt until it was full up. Simples.
The jar and water make the limes an extra luminous green and, even if the taste isn't up to scratch, they do look rather lovely. Now to wait three weeks for the verdict....