Come and listen to the story of a syrup long ago.
I made a juniper berry syrup in the fall of 1989 from ripe juniper berries (Juniperus communis). As I didn't have a reliable syrup recipe back then, I froze the half liter or so, like I usually did back then.
The problem with frozen syrup is, you don't remember that you have it, and thus don't use it when somebody in your household coughs.
So during the yearly defrost of my freezer, in February 1990 or so, when it's easiest to just throw all the frozen food outdoors (we usually have a week or three of -20 to -30 C in February), the juniper berry syrup got an airing. As in "Oh yes, the juniper syrup. I'll have to remember to use it next time somebody coughs." And the jar went back into the now defrosted freezer, along with the rest of the aired-out food.
The next yearly defrost was in February 1991 (or so), and the syrup jar got another airing: "oh yes, this one ...".
The next yearly defrost -- you can see where this is going, right?
Anyway, things repeated until the year 2000, eleven (11) years after I had made that syrup.
The syrup didn't go back into the freezer because it wasn't liquid anymore. (Frozen syrup stays liquid.) It was a clear greyish jelly. "Wheee," said I, shaking the jar about, "lookit that wiggle!" And sniggered, and shook the jar some more.
And put it in the fridge to see what would happen.
The syrup divided into two liquid layers as it unfroze: a clear layer on top and a whitish layer at the bottom. There was mold on the clear layer within a week.
Bummer, eh? Now I'll never know what that syrup might have evolved into in the freezer a decade or two down the line.
I expect that the clear layer was most of the water while the cloudy layer was the resins (+ oils) of the juniper berries plus most of the sugar.
I'm sorely tempted to put my recent pine'n'spruce shoot syrup into the freezer and let it languish there for a decade and more -- this syrup has loads of resins, too, in case that's what triggered the jelly. Alas, sanity prevails: while the freezer is big, I'm stuffing it to the gills with food, once the cheap veggie season arrives.
You ask, how do I know that the syrup was made in 1989? I've a phenomenal memory, kids. Except when it comes to remembering that oh yes, I have a syrup in the freezer.
And of course, I had written the date on the jar.
Related entries: Spruce shoot syrup