Apologies, I am not a master brewer, I just like to make some homemade wines from Hedgerow Fruits and the odd Kit when I have run out in the winter.
I also like to fortify my 'juices' and am curious as to what percentage I am ingesting.
If I have 1 litre of Vodka @ 40% and I add 1 litre of juice (0 % ) my resulting juice is 20%
Now - I am not too clever ------
If I add half a litre of juice to 1 litre of Vodka @ 40% - what is the percentage of my new juice? Is there a formula for this one?
Any clues on this would be appreciated, so I can tell my wife it is only ?% and can't hurt

Cheers BH