Ended up putting frozen tunas in a boil and mashed them with skins spines and all It was rather easy I thought. They smashed real easy and not much of anything left on the skins. Strained thru a fine screen and then thru a fine mesh grain bag. Ended up with four gallons of juice from 30 lbs. Used a gallon of water. Topped up with one gallon of blue berry pomegranate juice. 8 lb sugar and 1/2 cup lemon juice a little energizer 5 c tabs and 1118 yeast sg 1085. Smells really good now that the yeast is going.