Before century, all leavened bread was sourdoughbread, since they thought it was the yeast giving the bread the sour taste. Today we are able to produce yeast without lactobacillus which actually gives the sour taste.
How to Make a Disco Ball with CDs. You can still dance to old CDs even if you don't like the music on them any more. Just turn them into a disco ball to boogie under! It's a smart and fun project to recycle all those unwanted freebie CDs.