Iodophor Discovery – Cold Storage & Light Exposure

[BrissyBrew]

Idophor Discovery – Cold Storage

I have recently started kegging. I have an ultraflow which I disconnect and store in the fridge during the week. Being a sanitation nut I mixed a solution of idophor 1ml to 1000ml and put it in a spray bottle to sanitise everything! As I was using it to spray my quick disconnect and tap out I thought it would be easy to store the spray bottle in the fridge. What I noticed was the solution almost never faded in the fridge. When at room temperature I notice the colour normally fades over a day or two. So I decided to do a little experiment:

First I made a 1 L solution up 1ml to 1L. This was mixed well.
Then I put half of it in the spray bottle the other half in a 500ml bottle. The spray bottle when in the fridge the 500ml bottle (lab bottle clear) when into the fridge a 3*C and the lab bottle sat on the bench.

Result the Iodophor left the fridge has hardly faded after two weeks. Meanwhile the bottle on the bench has almost faded away.

So being a lazy experimenter I did not control for light. I should have put the bottle that went on the bench in a light proof container.

I would hazard to guess that storing your idophor in the fridge would assist in prolonging its self life.

 

[apd]

But can you draw the conclusion that the unfaded iodophor is still active? Is the level of colour of an iodophor mixture a standard way of measuring its sanitisation power?

 

[Finite]

Is the level of colour of an iodophor mixture a standard way of measuring its sanitisation power?

[post="112739"][/post]​

I was under the impression it is.

 

[Keith the Beer Guy]

Is the level of colour of an iodophor mixture a standard way of measuring its sanitisation power?

[post="112739"][/post]​

The colour is directly proportional to the concentration of the active ingredient. Once its done its job it is a colourless speicies.

So being a lazy experimenter I did not control for light. I should have put the bottle that went on the bench in a light proof container.

[post="112736"][/post]​

You will find that light, especially UV, makes more of a difference than the temperature.

 

[Trev]

I'm with Keith, light seems to be the major determinant.

I routinely leave a solution in kegs, bottles etc and if it is in the dark, or in the keg, it seems to last forever.

I also remember reading that colour is indeed an indicator of effectiveness. Keep in mind that the iodine-something_or_other that is the active ingredient is the same basic mechanism as Betadine. It keeps forever in the medicine chest out of the light.

Trev

 

[Finite]

You will find that light, especially UV, makes more of a difference than the temperature.

probably why it comes in brown or light resistant bottles. Much like beer in brown bottles has less chance to be skunked.

 

[BrissyBrew]

I might try again sometime this time with a few test tubes (smaller quantity to play with)

 

[Uncle Fester]

For what the Iodphor cost me, ($12 for 250ml), I use a fresh mix everytime I need it.

It also means that I dont have a toxic spray bottle hanging around within kids reach.

M

 

[smashed jaffa]

I have had a 1L spray bottle which I keep in my room at the back of my garage(read-brewery).

The light is never on unless I am in there, which is usally at night as I am at work during the day. I made a 1L solution two weeks ago and used the solution on the weekend to bottle a batch of Malt Shovel Nut Brown Ale.

I was a bit worried about it being OK, so I read the bottle and it states "solution loses it's effectiveness once the colour fades".

After two weeks in a room with a temp of around 24C but mostly dark, colour was still good so I used it! :blink:

I will let you know if the batch goes skunky! :huh:

Broken Aisle Candy.

 

[Jazzafish]

The following is from: http://www.howtobrew.com/section3/chapter14-5.html

The brewer can use iodine (or iodophor) to check a sample of the wort to see whether the starches have been completely converted to sugars. As you may remember from high school chemistry, iodine causes starch to turn black. The mash enzymes should convert all of the starches, resulting in no color change when a couple drops of iodine are added to a sample of the wort. (The wort sample should not have any grain particles in it.) The iodine will only add a slight tan or reddish color as opposed to the flash of heavy black color if starch is present. Worts high in dextrins will yield a strong reddish color when iodine is added.

Maybe next time spray something with starch and see if it turns black? Like a cut in half potato? If it turns black the idophor should be sweet.

 

[Airgead]

Maybe next time spray something with starch and see if it turns black? Like a cut in half potato? If it turns black the idophor should be sweet.

[post="112890"][/post]​

Jazz


That will tell you that there is iodine present but not at what concentration. You need a certain concentation to be an effective sanitiser. I suspect that it will turn a potato black long after it stops being effective. Same goes for colour. The colour shows that iodine is present but without a reference sample to check the degree of fading I wouldn't trust it.

Cheers
Dave

 

[BrissyBrew]

ok my last lot of test results are in, I thing I let my experiment run a little too long.

The three test tubes are from left to right

1. Exposed to light (not direct it is in my garage), and exposed to heat +30*C
2. No light, exposed to heat +30*C
3. No light, kept below 16*C (would have been nice testing a largering temps but I have an ale, well ginger beer, going in the fridge at present)

The photo is not as good as the naked eye. Tube 1 turned the lightest colour, next lightest was tube 2. Tube 3 faded the least.

Conclusion temperature does have an effect on storage of mixed idophor. Light also has an affect.

 

[homebrewworld.com]

My spray bottle is red in Colour.( cheapy from $2 shops )
I think this keeps the light out a fair bit, as my solution of Iodophor last for months, and keeps a real blood red colour.
Kept in the garage sometimes at 40c in /out of direct light.

 

[peas_and_corn]

When it comes to iodophor, it's best to just mix fresh when you need it. If you leave it, even if you are going by the results of these experiments, you are still not assured of its concentration

 

[pint of lager]

The stuff is cheap. Make a fresh batch up.

 

[BrissyBrew]

I do make up a fresh batch all the time,however I do keep a spray bottle around, I use it to spray the disconnect for my tap and the tap itself.

If you have some leftovers where you going to put it.
I have since wrapped my idophor (concentrate) in foil to cover it from the light.

 

[pint of lager]

That's great to read Brissiebrew. I was worried that the experiments meant that brewers wanted to keep the stuff and reusing it. The discussion has come up before about saving and re-using no rinse sanitisers and the tight fisted brewers keep wanting to save it.

On brewday, I make up a 4 litre solution and small items are soaked in there, and it also is used for rinsing fermenters etc. The following day, even after very cold nights, the solution has faded significantly. So you can definitely add sealed or unsealed container to your experiment.

I also use a spray bottle, the dilution is made a little stronger and it is kept in a cupboard. After a few weeks, that solution is dumped, the bottle recieves a napisan treatemnet, rinsed and a fresh lot made up. Using a syringe makes it very easy to make the correct solution concentration up.

 

[jagerbrau]

interms of it sanitsing what is the common use, ie fermenters etc

 

[warrenlw63]

Jagerbrau

I add 5ml to 5 litres of water. Then you just shake the fermenter around.

Warren -

 

[pint of lager]

Jagerbrau, the correct amount depends on your source concentration.

If you do a search on iodophor, there are a few pages of topics.

Have a read of this Iodophor link There are some excellent posts included.