Italian Baby sponge?

[Bob1]

Tom,
Years ago I saw these two videos and I could not find any info on them.  I have had sourdough starters and have worked with them so I am familiar with the process.  Is the process of wrapping the old dough and creating pressure used to control the yeast or change the flavor.  I would really appreciate some enlightenment on this.

<a href="http://www.youtube.com/watch?v=njR_gKl-S4s" target="_blank" class="aeva_link bbc_link new_win">http://www.youtube.com/watch?v=njR_gKl-S4s</a>

<a href="http://www.youtube.com/watch?v=llZhkGio1TA" target="_blank" class="aeva_link bbc_link new_win">http://www.youtube.com/watch?v=llZhkGio1TA</a>

Thanks,

Bob