Experiment: BWV (bleach-water-vinegar) as no-rinse sanitizer

The first part of the famous Basic Brewing Radio podcast with the StarSan inventor (mp3, ~11MB) talks about effective, 30-second wet contact, no-rinse sanitizing with a pH-modified bleach solution.

The process is this:
add 1oz of plain cheap bleach (no fragrance) to 5gal water, stir.
rinse the measuring device!
add 1oz of plain white vinegar.

That's it. [Vinegar is used to drop the pH of the solution into the 6.5-7.5 range for effective santizing -- see below. This solution now has sufficient hypochlorous acid volatiles for no-rinse sanitizing but the absolute amount of bleach is low enough to avoid contributing unwanted chlorine components to the brew.]

I normally use iodophor (or starsan for bottling). I am testing the BWV approach today anyhow to see how it works. I was bottling a batch of apfelwein and mixed up the BWV, using a graduated cylinder to measure the bleach and vinegar portions accurately. I used the BWV to sanitize the racking gear, bottling bucket, bottles, and caps.

There was a distinct bleach smell at that 1oz concentration. The podcast indicates that the bleach smell (and sanitizing effect) is associated with hypochlorous acid, and that the vinegar addition increases production of hypochlorous acid. This may suggest that what we perceive as the bleach smell may be less in a Bleach-Water solution than in a Bleach-Water-Vinegar solution. I did not think to test this.

This paper (pdf) from an Oklahoma extension service suggests the best pH range for sanitizing with bleach solution will be between 6.5 and 7.5. Below 6 can be somewhat more corrosive to materials, below 5 can cause unsafe chlorine gas production, and above 8 loses sanitizing effect. I do not have pH strips to measure that range so I don't know what my actual pH was.

The apfelwein batch I was bottling was a no-sugar version so the flavor will be mild enough to show any corruption by chloromines or whatever. We shall see. The cost is certainly low enough. Using my gallons of generic vinegar and bleach I had in the house a 5-gal batch would cost about 5c, or about 1c a gallon.

If this proves to be an effective, tasteless, no-rinse sanitizer I may refer to it as 1ozBWV. Although somewhat unhandy it contains the liquid measure of both additions and specifies the order of safe addition (bleach and vinegar are seperated by water).


UPDATE 20090118: I opened one of the bottles of apfelwein after 1 week to see if there were any bleach notes detectable. None, it was completely clean.

UPDATE 20090320: Have used no-rinse BWV on a few batches of beer and apfelwein with no off-flavors. My work was sampled by the local homebrew club.

REMINDER: Do not use bleach solutions on stainless steel.