Blackberry Cordial

I've been racking my brains for things to do with this year's spectacular blackberry crop (I've picked over 15lbs within 200 yards of my house) so decided to try this, which is supposed to be good for sore throats and colds. It involves macerating the fruit in vinegar, and the result does taste quite vinegary which is fair enough for a medicinal preparation, but I wouldn't offer it to anyone as a normal beverage. I had a sore throat last night so gave it a try and feel better today - whether this is a placebo effect, I cannot say ...