Colorless iodine solution -- until....

[highgravitybacon]

So I mixed up some iodine sanitizer. I use povidone iodine which is basically the same as IO Star. However, I notice that the water barely has any color to it at all. It's maybe, and this is a real little maybe, the slightest bit amber.

I never really trusted that so I always used star san.

Today, for my own amusement I mixed up a gallon of povidone-iodine cleaner. 1.25 ml / 1L. Again, hardly any color at all. On a hunch, I added a few drops of star san to this mix. It turned darker, but still crystal clear. A bit more star san and it was darker yet. And darker the more I add.

Why is this? Something is happening that as the ph drops, the solution gets darker and darker. Does Iodine need a certain ph to be effective? My tap water is fairly high ph. Usually from 9-10 or so. Is iodine going to be the least bit effective for me?

 

[highgravitybacon]

http://www.brewersconnection.com/classroom/Iodophor.htm

The answer is:
This particular iodine requires a low ph. The fact that it is colorless indicates that it is ineffective. Another site about food safety said that iodine based sanitizers are easily assessed by their color. An effective solution will be amber.

This tells me betadine or povidone iodine is not the ideal formulation for someone with alkaline water. IO Star, which I've never tried, may be better.

 

[Marquez]

Thanks for the post.

Its always good to know about the details about the products we use.