Fire away! I’d be happy to answer questions regarding BTF Iodophor. I’ll start with a couple of great resources.
Here is a link to Basic Brewing Radio with our Executive VP, Murl Landman, discussing BTF Iodophor and cleaning and sanitizing in general from march 27, 2007:
Someone already linked another great reference from the Bay Area Mashers featuring an interview with Dr. Chuck Landman, but here’s the link again:
Hey, everybody, Jonathan is a great guy and a killer resource for iodophor questions. Use him! 
Ok, so 12.5 ppm concentration is used for no rinse. Recommended contact time is one minute ?
Yes, 12.5 PPM is the desired strength for a sanitize solution. Per the label, we suggest 2 minutes of contact time for sanitizing. However, “wet time” contributes to contact time - what that means in practical use is you can partially fill your container with solution, swirl around to contact all of the surfaces for 15-30 seconds, then invert to drain. The time spent draining and drip drying is going to be greater than 2 minutes, thus satisfying the contact time.
Usage rates for 12.5 PPM:
1 tsp in 1.5 gallons of water
1/4 oz (1/2 Tablespoon) in 2.5 gallons of water
1/2 oz (1 Tablespoon) in 5 gallons of water
Hope this helps!
I’m gonna print that out and tape it to the wall. Much easier than digging out the gallon jug. (I have my Iodophor in a tiny old Star San container so I can measure it.)
What’s the best temp? I’d never heard it wasn’t to be mixed with hot water. My usual procedure is to wash my bottles and then sanitize with iodophor mixed with hot water the day before I actually bottle.
BTF Iodophor is designed to be mixed into cool water. Avoid using hot water when mixing a solution. Hot water temperatures encourage the Iodine to gas off into the atmosphere at an increased rate, diminishing the strength of your solution very rapidly.
The other reason cool water is great is that it doesn’t cause the interior of your bottles or other containers to steam up - the steam makes it harder to dry your surface properly. The cool solution will just sheet right off and drip out rapidly.
Does sunlight exposure affect the Iodophor in solution - i.e., does it degrade more quickly in sunlight? Can it be stored in solution for any length of time and retain effectiveness , if covered in a white food grade bucket with lid or put into a spray bottle?
Two minutes, noted, not so long.
Typically storing a solution of Iodophor does not last very long. In an uncovered container, most of the available Iodine will gas off to the atmosphere in about 24-48 hours and you’ll be left with clear water and no more amber Iodine color. Covered or in a spray bottle, you may get longer than that. As for UV light exposure, I don’t have any timed trials that express how much faster a solution will degrade, but that’s something I can look into.
My best advice is to make small amounts of solution every time you have a beer related task - it’s very easy to measure and mix a 1.5 gallon batch of solution when racking, kegging, sampling, or bottling. I understand the convenience of the spray bottle (especially for Star San) for spot cellar related tasks, but the only true way to evaluate the strength of your stored solution of Iodophor is with Iodine test strips. As long as you have at least 12.5 PPM, you’re good to go.
I understand the required contact time of 2 minutes, but must the surface dry completely before use? Are there flavor impacts if the fermenter, keg-- whatever-- is still wet?
I have access to 10% povidone-iodine solution. How is this different? Can it be used in a similar manner to iodophor? On the package it states that it has 1% titratable iodine. Inactive ingredients are listed as citric acid, disodium phosphate, nontoxynol-9 and sodium hydroxide.
I have this formula for the dilution of iodophor: V = (0.0025*19L)/XX% where XX is the concentration of your solution, 0.0025 is 25ppm as a percentage, 19L is approximately 5 gallons, and V is the volume of your solution you need to add to five gallons of water.
If it is ok to use, do I base the dilution on the titratable percentage of 1% or 10%?
Thanks for your help!
Mac
In my experience, using a carboy/keg/bottle that still has a few residual drops of BTF Iodophor in it, at a proper usage rate of 12.5 PPM, has no flavor impact. I do this routinely and can’t taste any Iodine. A few stray drops of usage strength solution in a large volume of beer results in a potential concentration of Iodine in the parts per billion range. With solution greater than 12.5 PPM, I cannot guarantee this.
In a perfect world, air drying is suggested. However, shaking or dripping dry with a little residual solution isn’t the end of the world.
Please see the article I linked earlier - here’s a brief quote from the conclusion: http://www.franklinbrew.org/wp/?page_id=384
"Summary
Both testers easily detected iodophor in distilled water when the level of iodophor was 4 times “normal”.
Neither tester could find the iodophor in distilled water at twice the “normal level”.
Neither tester could detect iodophor contamination in SNPA at 8 times the “normal level”.
NOTE: by “normal level”, I mean the amount of iodophor that would be present when draining, (but not air-drying), a carboy as described earlier in this article.
Conclusion
I guess I won’t be rinsing carboys after sanitizing with iodophor anymore! There just isn’t any need to. Simply draining the carboy of the iodophor solution left only 1 teaspoon of solution behind and no tester could detect iodophor even when the samples were contaminated with the equivalent of 8 teaspoons."
Good info. Thank you !
Mac, great question!
First off, povidone-iodine solution is different than BTF Iodophor in that povidone is an FDA regulated, topical antiseptic, “medicine” regulated product. BTF Iodophor is an EPA/pesticide regulated surface sanitizer product. They both deliver Iodine to kill microbes, but are regulated by different entities for different purposes. Povidone-iodine is a ready-to-use product not necessarily designed to be diluted, BTF Iodophor is a concentrate designed to be diluted to a usage strength solution.
As an EPA registered manufacturer, we cannot suggest using a product outside of its intended, labeled use. There is a statement on our packaging that indicates “It is a violation of federal law to use this product in a manner inconsistent with its labeling.” Typically, federal authorities have other concerns than to beat down your door if you used a BTF Iodophor solution in an emergency medical situation or use a diluted povidone solution to sanitize your homebrewing equipment, but as a representative of a company that is regulated by the EPA, I can’t condone usage of a product that’s outside of its intended use.
Speaking strictly in terms of chemical activity, providone-iodine solutions diluted to 25 PPM may produce a solution that delivers enough available Iodine to kill microbes on the surface of your carboy/keg/container. However, the formulation of povidone and its other ingredients are not identical to BTF Iodophor, which is butoxy polypropoxy polyethoxy ethanol-iodine complex in a 1.6% titratable Iodine solution. I can’t verify that other ingredients in povidone, such as citric acid, disodium phosphate, nontoxynol-9 and sodium hydroxide will impact the quality of your finished beer if any residual solution enters your beverage. Ultimately, you would deliver kill strength Iodine, but you are introducing other factors.
So, in conclusion, if you try using povidone and don’t notice any ill effects and it doesn’t ruin your beer, more power to you. However, if you want a guaranteed Iodine sanitizer that has been designed, tested and regulated for sanitizing beverage contact surfaces, BTF Iodophor is the preferred tool for the job. Povidone may behave differently when in a diluted solution, such as foaming and not draining properly, whereas BTF Iodophor solution will sheet off your surface with minimal foam, drain quickly, and minimize the potential impact of residual available Iodine.
Fun fact, nonoxynol-9 is a spermicide. If you don’t want your beer getting pregnant, I’d go with your povidone.
Another thought - is the product affected by water composition? I have hard, iron rich well water at my house, so I use RO for brewing. Is the hard water just as good as soft water for Iodophor use, or would softened, but not RO, be a better base water for the solution?
Thanks for the great info!
We developed BTF Iodophor in Winona, MN, an area with very hard, high alkaline water on the Mississippi River. There are very few exceptions where a high alkaline pH of your water can impact how the solution behaves, but these are rare. If you’re able to, I would suggest using your softened water from your tap (I do this at home in a hard water area) and I think you’ll get more than adequate results.
Good to know. Switching to povidone iodine now…