I got this from an actual fish and chips shop (chippy) in Scottland while I was on subs in the navy.
English Fish Batter
2 table spoons of malt vinegar
1 1/2 lbs. of flour
1/2 table spoon of bicarbonate soda
3-4 egg yellows
Approx. 1 1/2 pints of water
Mix soda in tiny amounts untill mixed, mixture will bubble over if added too quickly.
Will batter approx. 6 fish.