blackberry whisky

This is a variation on sloe gin - and is better because it doesn't use sloes and doesn't use gin.
4 lbs of big juicy, organic, home grown frozen blackberries go into a washed sweet jar with 8 oz of sugar and a bottle of cheap whisky.
Shaken regularly so that the sugar is thoroughly mixed, it is then left (for up to two years) before being enjoyed.
Just imagine that combination of whisky and blackberries.
I don't think there's much chance of it lasting two years.
Cheers!