Originally Posted by Dwain
After your PBW circulation, what do you use for an acid rinse? Also, after the acid rinse, do you run "clean" water through it? Do you leave anything (sanitizer?) in the system between brews? If not, how do you make sure the lines are empty so they don't grow funk in them between brew sessions? Thanks - Dwain
I use a light solution (1 ounce per gallon) of Acid #5 from Five Star (38% Nitric Acid, 6% Phosphoric Acid). The acid rinse is my final rinse. I just drain the system and leave it exposed to air. The Nitric Acid in the product works to re-passivate the stainless steel. If a clean water rinse was done after the acid rinse it would defeat the re-passivation properties.
I don't leave anything in the system between brews (aside from air). I use Silicone hoses. The silicone combined with the alkaline cleaning and the acid rinse make for pretty sanitary conditions. Once clean, I disconnect the hoses, hang them and let them air dry. I suppose that even if there were some residual sugars that survived the cleaning process, the act of hanging the hoses keeps the ends pointed downward and in such nothing gets in them to get funky.
IIRC, Five Star suggests a brewday pre-rinse but, I haven't been doing that and have had no off flavors as a result. I usually only brew once or twice a month so, any moisture left on the system has evaporated before I pull it back out.
I could limit the rinse to every other cleaning but, my water is liquid rock and after 2 session I have scale buildup (especially in the HLT). With softer water only periodic cleanings would be needed to deep clean the system.
The Acid #5 is not marketed to HomeBrewers but is available and can be special ordered through LHBS. It aint cheap tho. I managed to buy mine in bulk and saved considerably. Even if I hadn't been able to buy it wholesale, I;'d still buy it and use it. I find it to be indespesible in keeping my rig spotless, shiney, and in prime condition. Not to mention the wonders it does for my plate chiller.
The only issue with Acid #5 is it will re-act with soft metals so, if you have copper or brass in your system this stuff may not be for you unless you only use the light solution and only for periodic deep cleaning plus limit conytact time to 15 minutes max. This assurance comes from Five Star as I currently have a copper heat exchanger tube (RIMS). I'll be replacing it as soon as a stainless chamber is released but based on the info above I don't expect (and have not found) any pitting or corrosion in the copper chamber.