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Author Topic: Sanitizer Comparison  (Read 12699 times)

Offline erockrph

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Re: Sanitizer Comparison
« Reply #30 on: November 08, 2015, 10:50:18 pm »
Let me try to touch on a few things that have been brought up.

The plates are from White Labs online shop at yeastman.com - anyone can set up an account and order online. Be aware that some selective media plates have a very short shelf life. One product that I wish I bought in quantity is their sterile 50mL vials. They have a conical bottom, but also a ring to keep it upright. It's a great vessel for the first step of growing up some yeast. I did have one contaminated agar plate from them. I'm hoping that it was a fluke and not a QC problem on their end. As an aside, I picked two colonies from the contaminated plate to step up and they are putting out some serious honey aroma. I know pentanedione is supposed to be a flaw, but right now is smells really nice to me. I'll post more about my experience with WLP??? in the future.

As far as the experiment setup goes, I was not as concerned with the overall microbicidal activity of each sanitizer as I was in simply checking the effectiveness of each as a surface sanitizer for typical use in my home brewery. I am starting with equipment that I consider sufficiently clean of organic soils - everything cold side gets an extended soak and/or circulation with PBW and inspected for crud. I'm sure there are more accurate ways to test this out, but I still contend that my setup is a decent surrogate for this.

I am not claiming that the Star San is a superior disinfectant for treating heavily contaminated equipment. For those you need something broad spectrum (or just toss it if it's easily replaceable). But I do think that it passes the "close enough for government work" sniff test for clean equipment that will be innoculated with an active and/or sizeable pitch of brewer's yeast. I also think that an important part of sanitization that is easy to overlook is the "must remain wet for the entire required contact time" part of things. The foaming action of Star San is a big asset in this department. I suspect that once I flipped the agar plates to dry that some Star San clung to the plate for a while, essentially extending its contact time for a bit.

FYI - One of the reasons I chose tap water over an untreated plate as my control was to rule out a simple mechanical action of washing the contaminants off the surface as the primary mechanism of action. That certainly wasn't the case here. That seems to strengthen the case that at least some antimicrobial activity is at work here.

Regardless of my results, if I were working with a slant of a culture that costs well beyond the total of all my other ingredients in a batch, I would certainly be using something as broad-spectrum as possible and ensuring it stayed wet for an extended contact time. Or just flamed anything possible.

Personally, my motivation for performing this experiment was that I felt myself falling into the trap of applying my medical knowledge of disinfectants to the brewery. But the goals are completely different - in medicine your goal is to reduce the count of pathogens to as close to zero as possible. In the brewery, we just need to reduce the amount of contaminants to a level where your pitch of yeast can rapidly outcompete them. Frankly, looking at the sparse dozen or so colonies on the iodophor plate, that's probably well within the acceptable window.

One more random tangent I've thought of while mulling this all over - a solution containing both concentrated Iodophor and Star San diluted to the appropriate concentrations may pose the best of both worlds. The acidity of the Star San enhances the effect of iodophor, and the surfactant will keep it in place longer. Or I could just be half-asleep and rambling lol.
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Offline pete b

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Re: Sanitizer Comparison
« Reply #31 on: November 09, 2015, 07:52:15 am »
This is a great thread, thanks Eric for taking the time to do this and Mark for your extensive comments, I know you have been worried about burnout and I appreciate that you have remained active on this forum.
I have a few takeaways from all this. One comes from Mark's contention that this experiment is not valid because Star San is "cheating" by remaining on the surface longer (cheating is my word, not Mark's). Mark keeps alluding to the fact that the wort that is added to the fermenter will instantly wash it off and change the PH thusly making it ineffective. Fair enough but a fermenter is a very easy thing to clean thoroughly, I believe that washing and scrubbing with brewery cleansers that we all use (or soap and water for that matter) gets rid of enough of the microflora on its own to prevent infections and soaking in star san until wort is added keeps it that way. Since, as noted, Star San sticks to surfaces longer, its a good thing to have coating the surface of the fermenter wall above the wort level, keeping microbe growth in check until the krausen comes into contact with it before falling back into the beer. Also, wort that comes into contact with these surfaces should be getting a healthy pitch of the desired culture to overwhelm the small amount of microbes that survived, albeit in a weakened state.
I think the bigger problem is brewing equipment that is hard to wash: racking canes, tubing, spigots, bottling wands, air locks, kegging equipment etc. Its one reason I pour instead of rack my wort into the fermenter. These I currently soak in oxyclean and physically scrub what I can reach then soak in star san until use. This seems to do a good enough job based on no infections since using this method but they simply cannot be scrubbed thoroughly and should be replaced periodically. I wish I could soak them in alcohol but the volume needed is prohibitive. I do soak these in a bleach solution periodically and am considering quat tablets.
« Last Edit: November 09, 2015, 11:09:31 am by pete b »
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Re: Sanitizer Comparison
« Reply #32 on: November 09, 2015, 08:23:06 am »
I think the bigger problem is brewing equipment that is hard to wash: racking canes, tubing, spigots, bottling wands, air locks, kegging equipment etc. Its one reason I pour instead of rack my wort into the fermenter. These I currently soak in oxyclean and physically scrub what I can reach then soak in star san until use. This seems to do a good enough job based on no infections since using this method but they simply cannot be scrubbed thoroughly and should be replaced periodically. I wish I could soak them in alcohol but the volume needed is prohibitive. I do soak these in a bleach solution periodically and am considering quat tablets.

All of my tubing and brewing plasticware used to live in a bleach solution that was refreshed on a regular basis when I was still a single man.  I used one of those big blue tubs that have rope handles.  My wife was not crazy about that setup, so it went when she moved in.

The move away from glass to plastic fermentation vessels makes sanitizer choice much harder.   Glass is easy to clean and sanitize.   Plastic is more difficult to clean without damaging the surface, and it is porous (which is why my plasticware used to live a bleach solution.  The beauty of stainless steel is that it can be steam sanitized. 

Offline pete b

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Re: Sanitizer Comparison
« Reply #33 on: November 09, 2015, 08:36:49 am »
I think the bigger problem is brewing equipment that is hard to wash: racking canes, tubing, spigots, bottling wands, air locks, kegging equipment etc. Its one reason I pour instead of rack my wort into the fermenter. These I currently soak in oxyclean and physically scrub what I can reach then soak in star san until use. This seems to do a good enough job based on no infections since using this method but they simply cannot be scrubbed thoroughly and should be replaced periodically. I wish I could soak them in alcohol but the volume needed is prohibitive. I do soak these in a bleach solution periodically and am considering quat tablets.

All of my tubing and brewing plasticware used to live in a bleach solution that was refreshed on a regular basis when I was still a single man.  I used one of those big blue tubs that have rope handles.  My wife was not crazy about that setup, so it went when she moved in.

The move away from glass to plastic fermentation vessels makes sanitizer choice much harder.   Glass is easy to clean and sanitize.   Plastic is more difficult to clean without damaging the surface, and it is porous (which is why my plasticware used to live a bleach solution.  The beauty of stainless steel is that it can be steam sanitized.
The most abrasive thing I use to clean my plastic fermenters is a terry cloth towel and they all have remained free of (visible) scratches. I have dozens of glass carboys I use mostly for secondary and aging of mead. A cleaning solution and bottle brush works but I sure do wish I could get my arms in there.
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Offline stpug

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Re: Sanitizer Comparison
« Reply #34 on: November 09, 2015, 09:32:33 am »
The initial results are intriguing for sure - hopeful, even. However, I do think that more tests using different methodology are needed to give a better representation of sanitizer effects. My gut reaction is that StarSan works and Mark is wrong :P, but that conclusion is too simple to jump to and I've been burnt by "intuition" too many times.

Sooooo.... What if a 5 ml of highly contaminated culture slurry (blend of sour dregs for instance) were added to 1000 ml of the various sanitizers (B151, iodophor, starsan, bleach water, etc) and then allowed to soak for the stated time, AND THEN streaked onto sterile plates. Would the resulting growth colonies then be representative of what's making it's way into our beer? IME, this gives the sanitizer the best possible chance of success based on manufacturers instructions.

In addition, it would seem necessary that one should streak a plate with a batch of wort just after chilling while still in the BK. This would also give insight into the microbe load that comes with our wort after having only been boiled and being exposed to the environment during the chilling phase. After all, this microbe load is something that most homebrewers experience unless chilling under a hood or covered (both of which could be individually evaluated on plates as well).

Offline denny

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Re: Sanitizer Comparison
« Reply #35 on: November 09, 2015, 10:23:38 am »
Once again, we're at a dichotomy of science vs. results.  I began homebrewing using BTF Iodophor and used it excliusively for 6-8 years.  After developing what I think was a persistent low level infection, I switched to StarSan and it went away.  I've used it now for at least 10 years and hundreds of batches and have not experienced an infection.  To me, that's pretty good proof.  However, after reading Mark's info about Iodophor, coupled with the fact that I work with the company that makes BTF Iodophor, has made me want to give it a second look.  I have a new bottle that I'll start using and compare the results.  So, while you guys are debating experiment protocol and the finer points of chemistry, I'll be brewing delicious beer and find out for myself.  Frankly, what I expect is that I'll see no difference and conclude that both are fine sanitizers.
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Re: Sanitizer Comparison
« Reply #36 on: November 09, 2015, 10:24:03 am »
Sooooo.... What if a 5 ml of highly contaminated culture slurry (blend of sour dregs for instance) were added to 1000 ml of the various sanitizers (B151, iodophor, starsan, bleach water, etc) and then allowed to soak for the stated time, AND THEN streaked onto sterile plates. Would the resulting growth colonies then be representative of what's making it's way into our beer? IME, this gives the sanitizer the best possible chance of success based on manufacturers instructions.

All of the sanitizers used in brewing are effective against bacteria to some extent.  The ability to kill yeast and mold are the areas that differentiate sanitizing agents for the most part.  A more representative microbe source would be wort that is left to stand out in a home for a twelve hours before being covered and incubated.   Most houses contain non-brewing yeast genera as well as mold spores to some extent. 

The page linked below does a good job of explaining various sanitizing agents, including their modes of action and their weaknesses.  With respect to acid-anionic sanitizers (the class to which Star San belong), a common theme is limited yeast and mold activity.  The fact that people are acid washing yeast cultures with Star San goes a long way towards proving my point as well as the point made by the author of the linked web page and several other publications that claim the same thing.

https://edis.ifas.ufl.edu/fs077
« Last Edit: November 09, 2015, 10:26:11 am by S. cerevisiae »

Offline HoosierBrew

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Re: Sanitizer Comparison
« Reply #37 on: November 09, 2015, 10:36:12 am »
Once again, we're at a dichotomy of science vs. results.  I began homebrewing using BTF Iodophor and used it excliusively for 6-8 years.  After developing what I think was a persistent low level infection, I switched to StarSan and it went away.  I've used it now for at least 10 years and hundreds of batches and have not experienced an infection.  To me, that's pretty good proof.  However, after reading Mark's info about Iodophor, coupled with the fact that I work with the company that makes BTF Iodophor, has made me want to give it a second look.  I have a new bottle that I'll start using and compare the results.  So, while you guys are debating experiment protocol and the finer points of chemistry, I'll be brewing delicious beer and find out for myself.  Frankly, what I expect is that I'll see no difference and conclude that both are fine sanitizers.


^^  Agree 100%, Denny.  I used iodophor for years before the switch to Star San - which means I should've brewed infected beer occasionally or even semi-regularly after the switch. Not so.
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Offline pete b

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Re: Sanitizer Comparison
« Reply #38 on: November 09, 2015, 11:14:09 am »
Once again, we're at a dichotomy of science vs. results.  I began homebrewing using BTF Iodophor and used it excliusively for 6-8 years.  After developing what I think was a persistent low level infection, I switched to StarSan and it went away.  I've used it now for at least 10 years and hundreds of batches and have not experienced an infection.  To me, that's pretty good proof.  However, after reading Mark's info about Iodophor, coupled with the fact that I work with the company that makes BTF Iodophor, has made me want to give it a second look.  I have a new bottle that I'll start using and compare the results.  So, while you guys are debating experiment protocol and the finer points of chemistry, I'll be brewing delicious beer and find out for myself.  Frankly, what I expect is that I'll see no difference and conclude that both are fine sanitizers.


^^  Agree 100%, Denny.  I used iodophor for years before the switch to Star San - which means I should've brewed infected beer occasionally or even semi-regularly after the switch. Not so.
+2 I don't doubt the facts Mark is referencing at all, I just think Star San is plenty good enough on well cleaned equipment as evidenced by low levels of infection or no infections on hundreds of batches by many homebrewers on this forum alone.
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Offline Whiskers

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Re: Sanitizer Comparison
« Reply #39 on: November 09, 2015, 03:29:39 pm »
I wonder how different things would be if no sanitizing was done at all, but general cleaning was done very thoroughly.  I wonder too how a final rinse (again, no sanitizing) with boiled and/or autoclaved water would differ from a final rinse with sanitizer that was mixed with "unsanitary" RO or tap water. 

For many years I used a gravity transfer on the cold side.  I had no way to recirculate hot wort through the plate chiller.  To be on the safe side, I would always boil the chiller and cold side tubing (including the O2 tubing and stone) first thing brew day.  I'd usually dip all of this in starsan right before use, thinking that I'd be taking care of anything that settled on the equipment (or came from my hands) while I was assembling things after removal from the small boil pot I used for the equipment.  Sometimes the stuff was still hot when I needed it, and the starsan was a way to cool it down for easier handling.  Perhaps the starsan dip was not needed and perhaps counterproductive? 

Offline coolman26

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Re: Sanitizer Comparison
« Reply #40 on: November 09, 2015, 03:39:10 pm »
I agree with all of this.  I did take Mark's remarks on bleach to heart.  I've used Star San mixed with distilled water for a long time.  I did however, just sanitize all my equipment with bleach last week just to make sure.  I will do so periodically just for piece of mind.  Sometimes I'm blown away with the technical knowledge floating around this forum.   
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Offline pete b

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Re: Sanitizer Comparison
« Reply #41 on: November 09, 2015, 03:57:13 pm »
I'm pretty convinced that cleaning is way more important than sanitizing. I think a lot of infections come from organic matter several cells thick on hard to clean pieces of equipment, not on the wrong choice of Sanitizer.
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Offline Whiskers

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Re: Sanitizer Comparison
« Reply #42 on: November 09, 2015, 04:39:46 pm »
Beerstone/Calcium oxalate can trap biological contaminants or so I've read.  It can be a pain to remove without the proper chemicals and mechanical action.  Side-track note - sorry.

I think that sanitation chemicals are supposed to close the gap between the limits of cleaning and a biologically clean surface.  I suppose that what you ask of them is directly related to what you might expect to be left after cleaning.  I don't really know what one might expect to be left. 

If the sanitizing agent just puts certain organisms in stasis, then you'd expect that any of these introduced with the water in the sanitizing mix to become active once their environment becomes wort. 

In an ideal world you'd want the agent to denature the organisms DNA.  That's what UV is supposed to do I think. 

Offline erockrph

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Re: Sanitizer Comparison
« Reply #43 on: November 09, 2015, 05:07:08 pm »
I agree with all of this.  I did take Mark's remarks on bleach to heart.  I've used Star San mixed with distilled water for a long time.  I did however, just sanitize all my equipment with bleach last week just to make sure.  I will do so periodically just for piece of mind.  Sometimes I'm blown away with the technical knowledge floating around this forum.   
Bleach certainly can't hurt, as it is more broad spectrum than the sanitizers I tested, but it is also more sensitive to organic material than the sanitizers I tested here. That means that cleaning is even more critical before bleach.

Of note, bleach is sporicidal, while Iodophor, Star San and even ethanol or isopropanol are not considered sporicidal. The caveat is that any disinfectant requires an extended contact time, and possibly higher concentrations, to kill off spores. Bleach needs a 10 minute contact time at a higher concentration (5000 ppm, IIRC) to be effective against spores.
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Re: Sanitizer Comparison
« Reply #44 on: November 09, 2015, 09:07:02 pm »
I'm pretty convinced that cleaning is way more important than sanitizing. I think a lot of infections come from organic matter several cells thick on hard to clean pieces of equipment, not on the wrong choice of Sanitizer.

There may be more of a grain of salt to your claim.  There was a period of time where I stopped sanitizing my kegs.  I used old-school unscented powdered automatic dishwasher detergent, which is an incredibly good cleaner if one can still find it.  Old-school powdered automatic dishwasher detergent is basically PBW at a much lower price point.  My water supply was chlorinated, and I would crank my hot water heater up to 140F on brewing and kegging days.  That's hot enough to render hot water vegetative cell free.   I had to completely revamp my process when I moved to a house with a non-chlorinated water supply.