View Full Version : Tank PH

A Brady
04-13-2004, 03:38 PM
I was wondering what PH other brewers are leaving empty tanks at until they are used again.
I would also like to hear how you are getting these PH conditions and what you may do before using these tanks again to alter the PH, if anything.

I am currently using chlorine dioxide for sanitizing and am looking into the PH values involved in using this product.
I know the issues involved in PH and activating this sanitizer, thats not what I need to hear, just looking into dry storage conditions (storage meaning a day or two).

Thanks to all in advance!!

04-14-2004, 07:27 AM
A Brady
I have not recently checked the ph of the chlorine dioxide sani when I run my cip. However, what has been working well is leaving the tank packed with the sani after cip is complete and having the brewers dump it before they fill it with product whether it is immediatly or a day or two. This way the chlorine dioxide fumes/solution continue to sanitize the tank untill it is used.

04-14-2004, 07:48 AM
My understanding is that a chlorine dioxide solution is only effective for a few hours after activation. One article on the subject suggested an 8 hour shift as the maximum time to use it. Once it is activated and the gas is released there is no residual effect. As far as tank PH it is a good idea to leave the unused tank in an acid condition which could be acomplished by a post cleaning acid rinse or if you are properly activating your sanitizer that would also leave the tank acidic. However you should only be sanitizing the day your going to use the tank not the day before. Hope this helps.

04-14-2004, 10:58 AM
Good tip. I agree with the 8 hour max. time limit. For the brewery I am at now I CIP tanks/misc cellar work from about 8pm-4:30am and the brewers usually start at 3:30-4am so it works for us.

A Brady
04-14-2004, 02:43 PM
Thanks to everybody for your info.
I wanted to clarify the info Im really looking for...
I clean my tanks when they are emptied and sanitize them before filling them.
I want to see how others are leaving the tanks during the cleaning/sanitizing gap.
If they are left acidic, how is this ph achieved?
So on...


04-15-2004, 05:51 AM
Like almost everyone else, I caustic wash, rinse, acid wash and rinse prior to tank inactivity. pH only applies to aqeous solutions, it has no relavance to a dry tank. And any acid residuals rinse very well, unlike caustic solutions.

scott isham
04-15-2004, 06:03 AM
I also caustic wash and then use an acid (phos/nitric blend) rinse and then let the tank air dry. From what I hear, allowing a tank to air dry after an acid rinse will build up a passivation layer, which will make future cleanings a lot eaiser.


04-15-2004, 06:16 AM
This is straight out of some 5 star literature regarding cleaning fermenters, and I paraphrase "Use a hot alkaline wash on the vessel for 30 minutes, burst rinse with hot water and then Acid rinse with cool water at a rate of 1 oz acid per 10 gallons water. This will leave your tanks in an acid condition and retard bacterial growth." So basically if you want an acidic tank, after your final water rinse put a very weak acid solution into the fermenter and recirculate for a couple minutes and drain but don't rinse with water. This is different than an acid wash. I hope this helps. As far as measuring the PH of a dry tank I don't know. Maybe you could Acid rinse let dry and then spray just enough distilled water on the inside to collect a sample for your PH meter. If you acid rinse, and don't flushthat tank with water your tank should be left in an acid condition, and if that is your goal the actual PH shouldn't matter too much. As a precaution you might want to check the PH of your chlorine dioxide solution after it has recirculated in an acid rinsed tank to make sure the residual acid doesn't drop your PH below safe levels or you could quickly do a water rinse directly before sanitizing to eliminate any acid. Actually I think a potable water rinse is required by law if you use an acid cleaner that is not 100% food grade acid. You could do your acid rinse with food grade phosphoric acid and not rinse with water. Sorry this was supposed to be a short answer.

A Brady
04-15-2004, 05:43 PM
The "tank ph" is measured by rinse water collected off of a dry/stored tank, so in that respect it is an available number dry or wet (based on the ph of the first liquid running off the tank).
Thanks again to everyone for the info and to some for the attitudes...

I remind everybody that this is but one of the sources pro brewers use to share info and add to the community of PROFESIONALS.
This isnt a pissing contest and we arent emailing resumes to each other.
If you cant add to a subject without trying to make yourself sound more experienced than you really are, go check your email or something.

For all of you who truely help everyday I say cheers, everyone else, Dont worry, have a homebrew....
(this is all based on other probrewer experiences)

05-10-2004, 10:46 AM
This is probably a bit stale since the conversations happened a while ago. However, chlorine dioxide is active when it has been activated or not. Unactivated ClO2 is effective at higher concentrations and does not require a change in pH to release the chlorine gas which is safer for the employee, but also requires nearly double the concentration (=$). Nevertheless, activated ClO2 is plenty good and should you be storing a tank for longer than 24 hrs. before filling, bring the tank temperature down a bit (40-45 F) to inhibit the growth of any microbes should they be present. This has worked well for us provided the tank has been effectively cleaned. Cheers!

02-04-2005, 08:44 PM
At our brewery we CIP our tank and let it sit open so it will stay dry and them right before we use it we pump about 15 gallons of mild iodine solution through the spray ball and let it run out the bottom of the cone and then push the rest out with a little co2 then filler up.

dick murton
02-05-2005, 12:31 PM
Have to say that having had beer spoilt through iodine and chlorine contamination on a number of occasions over the years, I would prefer to use peracteic acid or chlorine dioxide as the final sterilant unless you rinse off with guaranteed sterile water.

And how would you sterilise it ? - ClO2 or UV are most commonly used