A raising mixture made from hops, water, flour and yeast applied to a mashed-potato-and-flour bread dough. Known only from Mrs.B, and unknown from local enquiries around Kirkleatham, near Redcar.

Original Receipt in 'The Book of Household Management', 1861, edited by Isabella Beeton (See Mrs.B)

KIRKLEATHAM YEAST.
1717. INGREDIENTS: 2 oz. of hops, 4 quarts of water,½ lb. of flour,½ pint of yeast.
Mode: Boil the hops and water for 20 minutes; strain, and mix with the liquid½ lb. of flour and not quite½ pint of yeast. Bottle it up, and tie the corks down. When wanted for use, boil potatoes according to the quantity of bread to be made (about 3 lbs. are sufficient for about a peck of flour); mash them, add to them½ lb. of flour, and mix about½ pint of the yeast with them; let this mixture stand all day, and lay the bread to rise the night before it is wanted.
Time: 20 minutes to boil the hops and water.
Sufficient:½ pint of this yeast sufficient for a peck of flour, or rather more.