Re: Why would this happen-
"...Rowan Jelly..."
Rowan Jelly is quite bitter and is an ideal compliment for meat or game. It's excellent on roast lamb for instance. Imagine a more sour and bitter version of redcurrant jelly and you won't be far off. It's easy to make and rowan trees tend to grow in abundance in public parks, etc. where the fruit is easy to gather. Don't eat the raw fruit, though.