Marty, this is an excellent question. I will dig into specific water pH thresholds where Iodophor solutions become difficult to maintain. We did develop the product in Winona, MN, which has tremendously hard water right on the Mississippi River - however hardness and pH are slightly different discussions. I recall a client that had municipal water coming out at a pH of 9 that had difficulty mixing Iodophor solutions.
With an RO system at home myself, I usually use my RO water for small batches of Iodophor solutions when I brew.
I will run this up the chain to Dr. Landman, the developer of the product, for his input and post back with a more specific answer.
For the purposes of disposing of spent solution, I would consider it just water (free of Iodine). I wouldn’t personally use it for anything else other than dumping it down the drain. This is why I make very small volumes of solution at a time - 1 tsp of concentrate for 1.5 gallons of water will do the trick for just about anything for home brewing related.
Back when i first started brewing (back in the dark ages :D), I kept Iodophor in a closed keg before I knew all the particulars of the product. When it turned clear, I just dumped some more concentrate into the keg. The beers started tasting like crap using this method since I used that same keg for the batch of beer. I stopped doing that and started making up a new solution every time I needed it since, as Rob said, it’s cheap. Problem solved. I now use SaniClean for sanitizing because it doesn’t foam and will keep for a month or two when mixed with R.O. water (I keep it in a Gott Cooler and check the pH of it every time I brew) (apologies to Craft Meister).
I also just dumped it down the drain to my septic system, along with other cleaning and sanitizing products and have not seen any adverse impact.
Hey Marty, I have some information back from Dr. Landman for you on this topic regarding pH for mixing Iodophor solutions:
"Absolutely. pH 8.5-9 is considered aggressive toward iodophors and requires a higher dose of concentrate to achieve a 12.5-25ppm solution. Above pH 9, the water needs to be treated with a weak acid (typically citric acid) to buffer the diluent back to the 7-8 range before dosing with the iodine concentrate.
… the high pH on the alkaline side prevents the iodine atom from releasing off the organic carrier molecule. It is the release of the free iodine atom that forms the active form of iodine that kills bacteria, etc. It is called hypoiodous acid … that and elemental iodine are bactericidal. Elemental iodine is hard to get into solution … hard to dissolve. The hypoiodous acid dissolves easily into water.
The older, original dairy iodophors were formulated with a high percent of some acid … phosphoric acid, Hydroxyacetic acid, etc. … to keep the pH low and help release the iodine."
That sounds just like the popular “recipe” for using bleach with sodium hypochlorite diluted to 80 ppm, where it is said to be essential to acidify to pH 5.0 in order that the chlorine will be almost entirely in the form of hypclorous acid, that being the active killer. These halogens all behave alike, it seems.
So, does this mean we should be checking the ph of our solution, or does the color indicator have our backs?
I don’t think it’s necessary to measure the pH of your water or Iodophor solution. It’s probably a better idea to understand the pH of your tap water or source of water for mixing the solution as I think it’s very rare to have a municipal water source coming out at a pH higher than 8.5-9. Using the regular guides of solution color and Iodine test strips will be an effective measuring tool, along with proper measurement of the BTF Iodophor concentrate.
“I’m familiar with this keg purging method, especially as suggested by Drew and Denny on Experimental Brewing. Denny has conducted his own tests on purging kegs with an Iodophor solution and says to me that it works great.
It’s kind of hard to put a length of time for how long something will stay sanitized. The best advice would be to use that keg as soon as it’s dry after sanitizing. Typically what I do is to store my kegs clean, then upside down/inverted to dry, then sanitize right before use. Bacteria and other bugs travel on airborne dust and particles, so the more time you leave a container open to the air, the more chance there is for contamination.”
Do people let items dry after sanitizing? In the 13 or 14 years I’ve been using Iodophor as a sanitizer, I have never (and I mean not once) waited for something to dry after I’ve sanitized it.
It also doesn’t seem to jive with the “sanitize right before use” advice.
A purged and sanitized keg isn’t going to dry unless you open it, which would kind of defeat the whole point.
I let it drain – I don’t, say, rack into a fermenter with a puddle of iodophor in the bottom – but I try to use stuff while still “wet” as I figure that means it is still sanitized, as you say, narcout. Even though it’s “no rinse,” I like a balance between adding as little solution as possible to my beer and waiting so long that I might need to sanitize again. But…
On the other hand, maybe in an irrational contradiction, I often sanitize my fermenter ahead of brewing and close it up still wet. Does this carry a risk of something present on a speck of dust in the air inside contaminating my beer? I figure the wort will be in contact with the air as the fermenter is filled no matter what. Maybe should consider that with regard to saniting all equipment, so if it dries, the surface is only as prone to contamination from the the air as the wort itself is. If a surface has been thoroughly cleaned and sanitized once, maybe we shouldn’t worry too much.
Here’s my general philosophy. Cleaning is of primary importance, sanitizing is just feel-good insurance. Sanitizing is killing the stuff you left on a surface, cleaning is removing it in the first place. Clean surfaces are the least possible source of infection. The one thing we can’t clean or sanitize is the air (unless you’re brewing in a NASA clean room.)
Same here. As I see it, that approach to closed fermentation, sani purging and closed transfer provides for a sanitary environment after we’ve pitched and closed up. We just need to be sure there’s nothing taking up residence in nooks and crannies or a biofilm in our cold side equipment. That’s more down to cleaning, including beer stone removal, than sanitizing.
I can get just about all but maybe a ml or two of sanitizer out of the keg by rocking it around while continuing to blow in CO2 after the keg is emptied. Obviously, if you shorten the dip tube, this will be harder to accomplish. I do not open the keg and let it air dry as I agree it defeats the purpose of a closed system transfer.
Goose, I have trimmed dip tubes, but I use this trick I picked up here on the forum. I also have my gas tubes trimmed to be flush with the inside surface of the keg, or actually slightly recessed. I blow out all the iodophor I can through the liquid side. Then pressureize and invert the keg. With the keg positioned so that the gas post is the lowest point, pop on a gas QD and blow the remaining iodophor out.
The main reason we stress the air drying aspect for using the BTF Iodophor solution is that those instructions are stated specifically on our label. With EPA regulated products, instructions, methods, and applications are strictly adhered to, especially for commercial use.
However, in real-world applications, air drying may not always be necessary. The best reason for air drying is to eliminate the opportunity for small amounts of Iodine to get into your beverage. The chances, when PROPERLY MEASURING an Iodophor solution of flavor impacts from residual Iodine, are slim to nil.
Here is an external link to a great document from an interview with Dr. Landman on BTF Iodophor:
Wow. Five pages, an expert, a lot of discussion, but not a clear answer to my original question, unless I missed it. If I measure the proper amount of iodophor into a five gallon keg, seal it, then push it out with CO2 into another keg, there will be no air drying involved. I’m OK with having a small amount of dilute liquid under the dip tube and I feel that that first corny keg is sanitized and ready to fill with beer.
Now what if I leave the other keg full of sanitizer until the next time I have beer ready to keg? It’s in the dark without oxygen in the head space. It may be a couple of weeks before I push out the solution with CO2 into another keg.
From what I have read here, the answer is that this probably works, but since it is so cheap, why am I doing it? Because I have lots of kegs and it’s nice to clean and sanitize them at one time.
This weekend I think I will pull out a sample from a keg with three week old iodophor and check for amber color. Will that be as definitive as a test strip?
Air Dry?? I had to go into the brewery and take my bottle off the shelf and read the instructions, but it does say that. The REALLY troubling thing is: “Why did EPA require this?” or “Why did National Chemicals agree to this requirement?”
I’m afraid that you’ve just opened a can of worms, but I’m still not about to begin air drying a piece of equipment and have it pick up mold spores. As far as I’m concerned, air drying would bring iodophor back to being no better than an acid-based sanitizer…ineffective against mold spores.
Jeffy, something I don’t quite get about your procedure. If a little bit of iodophor is left in each keg, then from the second one on, they aren’t completely filled to start. You can surely invert the keg briefly to get full coverage. But the headspace will be more and more as you go, which, it seems to me, means a little more air left unpurged each time – which could affect not only the beer, but also the iodophor. Am I missing something?