If so, how did you do it, what should I try? I plan to separate out some of my mother for experimenting so I don't contaminate and kill my nearly 2-year-old culture.
As an experiment with a portion of it, sure, go ahead. But here are some cautions: 1. Fruits. The sweetness will change the acid balance. Wild yeasts thrive in an environment that is slightly acidic, so you may in fact begin to kill off the wild yeast spores. 2. Alcohols. One of the by-products of fermentation is already alcohol. One of the signs on a sourdough starter which is on its way to perdition is an overly-alcoholic smell signifying that the yeasts have overconsumed their food source, and have begun breaking down the protein in the flour, and ultimately dying off. 3. Other cultures. Such as? Yogurt, sour cream, and buttermilk are "cultures", and I wouldn't recommend adding any of them to a sourdough culture.
This is all just off the top of my head. Let me think about it some more.
There may be an analogy here: my son was brewing beer, and thought he'd experiment by putting in some chopped dried fruit when he bottled it. It caused renewed fermentation (we think), and caps were popping off from the pressure and beer spilling out. A brewing guru told us, beer is bread and bread is beer.
Food (?) for thought.
I have very often pondered this same question . . . different cultures or "bugs" if you will, will give you different characteristics in say cheese or salami. So why not bread starters. I have had some sourdoughs that are better than others and I am convinced the bugs in them are different. I think it would be a brilliant idea to play with different cultures, yeasts or "bugs" to get different results. How about adding different cheese cultures to the starter? I bet you may end up with some wonderful results.