[Sca-cooks] Bread-baking with a biga

[Robin Carroll-Mann]

I'm planning on baking and freezing bread for my feast.  The recipes that look
the best to me are rustic Italian loaves made with a biga (sponge).  How can I
increase the biga (and the rest of the recipe) to make more than 2 loaves'
worth?  My oven will only hold two round loaves at a time, but I figure that I
can use the fridge to retard the rest of the dough.

Also, how do I substitute active dry yeast in a recipe that calls for instant
yeast?  Or should I?

Brighid ni Chiarain