That makes sense. But sometimes Mark's certainty in his statements reminds me of the Dave Line book form years past when he said that if you didn't get rid of your pets you'd always brew infected beer. There's science, where I take cues for learning the best practices. Then there's experience, which shows us if the science really matters.
What I meant by luck is just because you personally have not encountered a sanitizer's weakness does not mean that it does not exist. It just means that you have been lucky enough not to encounter it. The Internet is littered with data that demonstrates that acid-anionic sanitizers are bactericides, not broad-spectrum antimicrobials. My own experience with beers that plated positive for wild yeast infection after switching to Star San correlates with the published data. A local guy who I know had a persistent Brett infection that he could not get eliminate. He switched from Star San to paracetic acid (PAA), and the problem went away. This guy never had a problem with bacteria infection, even though his Brett beers were usually pitched with what are often referred to as beer spoilage bacteria.
The fact is Star San is an acid anionic sanitizer. Five Star even claims that it is a "high foaming, acid anionic
, no-rinse sanitizer" on their website (www.fivestarchemicals.com/breweries/homebrewing/products/
). Numerous publications state that acid-anionic sanitizers work via attraction to positively charged cells. Bacteria cells have a positive charge, yeast and mold cells have a negative charge (i.e., yeast and mold cells repel acid-anionic sanitizers). Since the active ingredient in Star San, dodecylbenzenesulfonic acid (see www.jstrack.org/brewing/msds/starsan.pdf
), is ineffective against yeast and mold, the only thing that Star San can do to yeast and mold is beat it up via low pH, which is the same thing that happens when we acid wash yeast.
From this publication: www.beer-brewing.com/beer_brewing/brewery_cleaning_sanitation/sanitizing_agents.htm
Anionic acids are one of the fastest growing sanitizing groups in the craft brewing industry. They are chemicals composed of two functional groups-a lipophilic portion and a hydrophillic portion-which results in a negative charge. The negatively charged anionic acid sanitizers react with positively charged bacteria by attraction of opposite charges
From page 9-6 of this publication: http://jifsan.umd.edu/pdf/gaqps_en/Section9.Effective_Cleaning_and_Sanitizing_Procedures.pdf
"Acid-anionic sanitizers are broad spectrum against bacteria and viruses, but not very effective against yeasts and molds
" iv. Acid Anionic Sanitizers
These formulations include an inorganic acid plus a surfactant, and are often used for the dual function of acid rinse and sanitization. Unlike QACs, they are negatively charged. Their activity is moderately affected by water hardness. Their low use pH, detergency, stability, low odor potential, and non-corrosiveness make them highly desirable in some applications. Disadvantages include relatively high cost, a closely defined pH range of activity (pH 2 to 3), low activity on molds and yeasts
,excessive foaming in CIP systems and incompatibility with cationic surfactant detergents."
From https://books.google.com/books?id=lCRxcp3gfhUC&pg=PA180&dq=acid-anionic+sanitizers++limited+activity+yeast+mold&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMI3_2lx_6ryAIVQR0eCh2tpAN2#v=onepage&q=acid-anionic sanitizers limited activity yeast mold&f=false
"Acid anionic sanitizers act rapidly and kill a broad spectrum of bacteria and have good bateriophage activity."
"These sanitizers can be corrosive to unprotected metals and a skin irritant, inactivated by cationic surfactants, may foam too much for CIP equipment, are less effective at a higher pH, have limited and varied antimicrobial activity (including poor yeast and mold activity)
, and are more expensive than the halogen sanitizers"
Note: The most commonly available halogen sanitizers are idophor and chlorine bleach.