On around day 2 I cooked four strawberries into a glass jar with the intention of hopefully filling it with strawberries over time… Sometime before 7pm on day 4 they were rotten 
Posting to make sure they’re intentionally supposed to go bad that quick…
Another strawberry related bit, I went out looking for more to fill said jar of cooked strawberries and (I think it was) sometime during day 2 the strawberries that spawned during worldgen were already rotten on the ground…
I think it’s normal, if you have sugar you can make strawberry jam which will last much longer.
It surprised me at first, too. Rotting times in Cata appear to be scaled to the default iirc 16-day season, so each ingame day represents about 6 days of decay… either that, or the Cataclysm has a side-effect of making things rot faster, which is how I interpret it in my head. But yes, this is working as intended.
This.
Having said that, if you travel beyond your ‘known world’ and enter areas of the overmap that you’ve never been to before, the strawberries you find growing there will be fresh for a few days after their overmap tiles spawn.