Will Iodophor Kill My Yeast


I just used iodophor for the first time, and I’m a little worried that I soaked my fermenter in an iodophor-water solution for so long that the leftover residue has killed my yeast.

I picked up some iodophor at a local homebrew shop yesterday and used it to sanitize my primary fermenter (food-grade plastic bucket) and equipment. In the past, I’ve filled my fermenter with a water / no-rinse sanitizer solution and left the mixture in the fermenter while I brew – typically a couple of hours. I did the same with the iodophor-water solution, which I created by adding four teaspoons of iodophor to roughly seven gallons of hot water. After draining the fermenter, I gave it a quick rinse with water and then let it air dry.

When I finally emptied the fermenter, though, I noticed that the inside of the bucket had turned a pale yellow. The white bristles of a brush that had been soaking in the solution also took on this same dingy color.

It’s now been 24+ hours since I pitched my yeast and I’ve yet to see any signs of fermentation – not a cause for alarm, but unusual. Is it possible that I left the solution in the fermenter for so long that it seeped into the walls of the bucket and that it’s now seeping out, killing my yeast?


Iodophor is a no-rinse sanitizer so don’t rinse. It’s also iodine based so it stains. The stain will not hurt you but it bothers you, bleach it out of it then rinse thoroughly.

Iodophor is a contact sanitizer, it sanitizes while it’s in contact with your equipment. Do not air dry. Just drain and use.

It’s best used with cold water as hot water reduces its effectiveness.

Here are some causes for a lag in start time:
1. Old or insufficient yeast cells. Patience or re-pitch sufficient healthy yeast.
2. Incorrect wort temp. Too high kills or at least shocks yeast or too low which will put them to sleep.
3. Bad seal on bucket which can mean that there is no lag at all.