what's it called when.........

You chop off a chunk of your current dough that has been made from a chunk the last batch and a new biga?

Whats the chopped off chunk from the previous dough called?

Or isn't it? Or is it a technique called .............

Here's a link you may enjoy reading: http://www.thefreshloaf.com/node/6429/039old-dough039-vs-pate-fermente

Hello,

I am sure there are many source but I chose wikipedia - Pre-ferment (http://en.wikipedia.org/wiki/Pre-ferment)

Old dough (pâte fermentée) may be made with yeast or sourdough cultures, and essentially consists of a piece of dough reserved from a previous batch, with more flour and water added to feed the remaining flora. Because this is a piece of old dough, it has the typical ingredient of salt to distinguish it from other pre-ferments.[7]

I believe this is what you are referring to.

Ben

that's it!

Thanks for the links.

I've been experimenting with my pizza dough, but couldn't remember what I was experimenting with, so to speak.