I was talking to my homebrewer friend and he told me that starsan does not kill wild yeast and that I should occasionally use iodine to switch s–t up on the beasties. can anybody confirm this concept of sanitizer switching?
I would use iodophor wherever possible and Star San as something in a handy spray bottle to use for quickly touching up surfaces, fittings and the like. It is true that iodophor is a broad spectrum and highly effective antimicrobial, and acid sanitizers like Star San are not effective against all beer spoiling organisms. You can search the forum for more info, this is a topic that comes up regularly. I don’t, however, see how “switching up” will have any effect. A particular chemical will either kill a particular bug, or it won’t. Every time the same.
The above statement isn’t necessarily true. Soymateofeo, the logic behind what your homebrewer friend told you is that the hardier microbes in your brewery can become, via natural selection, resistant to a sanitizer if it’s the only sanitizer you’re using over a long time period. It’s the same logic behind disease-causing bacteria becoming resistant to an antibiotic that is over-used. The definition of “long time period” will vary depending on your brewery and the bugs in it. But it’s not a bad idea to mix up sanitizers once in a while. That said, Sir Robert is right in that iodophor is very toxic to cells. It’s unlikely a microbe would ever evolve resistance to it. Same with bleach. Iodophor is a great bucket sani, while Star-san or Sani-clean are fine as spray sanis.
We cover this on the upcoming episode of Experimental Brewing. Here’s the explanation…
Broad-spectrum Germicides.
The term “Broad Spectrum” when applied to a sanitizer means that it will attack a wide variety of different types of microorganisms, including gram-positive bacteria (Listeria and Staphylococcus), gram negative bacteria (E. coli and Salmonella), viruses, fungi (both yeasts and molds), as well as many parasites. Broad-spectrum germicides act on microbial membranes, cellular enzymes, DNA, and protein. Iodine-based sanitizers have been used as antimicrobial agents since the 1800s and have a broad spectrum of activity They are a powerful sanitizer in strong acidic aqueous solutions. They are generally used at 12.5 to 25 ppm available iodine, and can cause staining on some surfaces, especially plastics.
Acid-anionic sanitizers are surface-active sanitizers, but negatively charged. Formulations include inorganic and organic acids plus a surfactant. Carboxylic acids (fatty acids) are some times incorporated as well. They are unaffected by hard water or organic soils. The dual function of acid is that it can be used for rinsing and sanitizing in one step. These sanitizers must be used at low pH. Activity above pH 3.5–4.0 is minimal. Acidity, detergency, stability, and noncorrosiveness makes them highly effective. Acid-anionic sanitizers are broad spectrum against bacteria and viruses, but not very effective against yeasts and molds.
Iodophors are considered broad spectrum anti microbial vs. Star San being a being anti bacterial. The actual label for Star San lists what it is registered to kill: E Coli and Staph A – the minimum baseline for allowing a claim of being a sanitizer with the EPA. Iodophor has proven effectiveness against not only gram positive and negative bacteria, but yeast, mold, fungi and viruses and is also a sporicidal agent.
That explains a whole hell of a lot. So how do you use star san and iodophor effectively? I’ve been scrubbing my fermenters and soaking in star san, along with all of my brew day stuff. What’s the best practice when using these two?
And thank you Denny! That’s very helpful! I hate iodine stains but it just may be a necessary evil. I have fruit trees in the yard.
I’m still surprised No-Rinse Bleach sanitizer never caught on. Especially after Charlie’s Basic brewing podcast from all those years back. That’s what I’m going to be doing.
I’m just too squeamish mixing a solution with both bleach and vinegar. I know in my head it’s safe as long as the vinegar is added to the already diluted bleach solution. Still scares me.
Embrace the stain. Beats dumping the beer. The only possible alternative to iodophor is chlorine bleach, which comes with several drawbacks: It must be thoroughly rinsed off, a real problem if your water is not guaranteed biologically pure, otherwise it will cause horrible chlorophenol flavors; it is corrosive to stainless, and cannot be used on copper or aluminum; and it requires considerably longer contact time. Its effectiveness is also dependent on pH and mineral content of water. Bleach can be used effectively to clean and sanitize (even disinfect) glass and plastic, but – all in all, iodophor is your best friend.
I’m still surprised No-Rinse Bleach sanitizer never caught on. Especially after Charlie’s Basic brewing podcast from all those years back. That’s what I’m going to be doing.
I just alternate them as I think of it. When I brew, I try to remember (hey, it’s not easy at my age!) which I used last and then use the other one. When I use brett, or other wild yeast, I always use iodophor.
To be safe and effective this does require attention to water chemistry, use of a pH meter to hit the precise range, and careful handling. Iodophor is the better option for those not confident in their ability, or caring to take the trouble, to manage this. Probably why it has not caught on. But, Big Monk, you will save some money for your trouble.
Iodophor is so fast, effective, and easy to use, I don’t understand why people bother with anything else.
Plus, it smells good.
Not sure I’d say it smells good, but I do enjoy it. Same with gasoline. The smell that is. Don’t sanitize with gasoline.
I love the smell of broad-spectrum antimicrobials in the morning…
I use both. On brew day, I make some iodophor up. I have a five gallon batch of Star San in a bucket that is used for non brew day (kegs, keg lines, etc.)
I almost do the same. Kegs and anything yeast related get iodophor, fermentors and other brewday gear gets starsan which I keep a bucket of. I will rinse and sanitize my empty fermentors with the iodophor when I am purging kegs as well.
Having read about iodophor staining plastic—does it stain Speidel fermenters?
Might. I haven’t had my Speidel very long. But I’ll happily stain it rather than have spoiled beer.
I’ve used it on plastic buckets for years, which I would guess are made of the same material. Never had any staining.