4 oz hops, 7 lbs treacle, 1 oz whole ginger, 5 1/2 gallons of water, 1 cup brewer's yeast.
Mix (all but the yeast) and bring to the boil. Boil for two hours. Transfer to a tub and let it cool a little. Add a cup of brewer's yeast and stir it well. Then put it in a barrel and let it stand for two days with the bung out and slightly cant the barrel. Then bung closely. Fit for use in a week.
Let us know in the comments below if you attempt to recreate one of these WW1 recipes!