Baker’s Topic, use of the Sponge
I am a fan of the sponge, whatever bread you are making. For savoury white breads I favour an overnight sponge, whether stiff like the traditional English sponge, or entirely wet like the French poolish. Sponging makes the bread have a deeper flavour, and the loaf retains its moisture for longer. Only a tiny amount of yeast is employed in the sponge – much less than 1% of the flour (unless you want it to sleep in the fridge when about 3-4% would be needed.
With sweet breads, like the Roscon de Reyes found in Spain to celebrate Epiphany and the Coming of the Kings (described in my last newsletter),when the yeast gets bogged down with rich ingredients like eggs and butter, the sponge will allow the yeast to get at its food better, and the sought-after lightness in the dough is more easily achieved. There is a wide range of sponges, some slow, and some quick. The quickies are the type that are called ferments, being very wet, using all the yeast and liquid with a small token of food (flour and sugar) to get the yeast flying. PANARY’s bun dough ferment would be a classic for this type – the one called the One Pint Ferment, which usually sits for barely three-quarters of an hour.
However, the slow ones are also very impressive, calling for a lightly yeasted and stiff dough to be left in a cool place overnight with none of the recipe’s sugar being used. To make one of these for a Roscon, I would take about a quarter or a fifth of the recipe’s flour, enough milk from the recipe to make a firm dough and just a little blob of yeast barely the size of a chick pea. It will swell and gas itself well overnight.
In the morning, one of the attractive things about the sponge system is its flexibility, allowing you to ferment the finished dough at a slow pace, just using the yeast that was placed into the sponge, or you can adopt a quicker pace to the fermentation by adding a little more yeast at dough-making time when you add the sponge to the rest of the ingredients.