translation.en: And it's made -- it can be a sourdough starter, or what we call a "biga" or any other kind of pre-fermented dough with a little yeast in it, and that starts to develop flavor also.
translation.zh: 它是一种酸性生面团，和其它加有酵母的预备面团一样， 被称为biga， 有特殊的香味。