Commercial contamination of starter

Toast

Browsing the net tonight and I cam across website that deals with all things fermentation amongst other things. There was a FAQ that discussed sourdough starters exclusively. One of the Q/A discusses the threat of contaminating a sourdough starter if it is kept too close to other rising breads made with commercial yeast and other fermenting foods. I recall reading something on the lines that if you were to add commercial yeast to a starter that it will soon eliminate the commercial yeast due to acid levels and bacterial growth. Just want to see what your thoughts were? If this is a possibility, what precautions do you take to eliminate this threat?

I think that the possiblity of ambient cross contamination is very low possibly close to zero.  Adding commercial yeast directly to a sourdough starter is another matter and this would have some effect on the starter.  Whether or not that effect would be long lasting, I cannot say.

This is not to be confused with recipes that call for both sourdough starter and yeast as that is an entirely different matter.

Jeff