Makeup Water for Sanitizing Solutions

[mabrungard]

I had an interesting episode with some contest samples I recently prepared and submitted that should be a valuable lesson for others. Many may recognize me as someone that pays particular attention to my brewing water quality, so it may come as a surprise that those recent contest samples were afflicted with chlorophenols! Here is why.

I am one who likes to bottle with bottles that are freshly pulled from the sanitizer solution and shaken out the best that I can. The problem was that I was using unfiltered tap water as the makeup water for the sanitizer and that does have chlorine in it.

While tap water can often contain something like 2 to 3 ppm chlorine, that content results in about 4 to 7 ppm dichlorophenol. Since the taste threshold for that compound is on the order of 10 to 30 ppb, you can see that there is potentially about 100 to 500 times more dichlorophenol than necessary for perception. I was sadly mistaken that the teeny bit of liquid residue remaining in my bottles would not bring my beer's dichlorophenol content above that limit. It did.

So let my experience guide you and be sure to either use dechlorinated water when preparing your sanitizing solutions or be sure that the residue on your bottles or equipment is fully (OK, mostly) evaporated before introducing the beer or wort.

Enjoy!

 

[bucketnative]

Did you experience the dichlorophenol off-flavor yourself, or are you relying solely on the judges' opinions?

I don't think it's as bad as 100-500 times greater than the threshold. Let's assume that there was 1 mL of sanitizer left in your bottle prior to filling. The sanitizer would represent approx. 0.3% of your bottle fill. That would yield approximately 20 ppb of dichlorophenol (if we assume the upper limit of 7 ppm resulting from your sanitizer). Right on the threshold, correct?

However, I used to just untreated use tap water for my priming sugar dissolution. Yikes. I always had this slight astringency/medicinal flavor. I made the rookie assumption that 1 cup of water wouldn't affect 5 gallons of beer. I started treating my water for priming with Camden, and that problem went away. So, you should definitely worry about the small things when it comes to the potential for these compounds.

 

[shoengine]

In before someone complains about the hassle of bottling!

My methods these days are to perform the clean/rinse/sanitize process, and then to run them through the dishwasher on the sanitize/heated dry cycle. The hope is that any volatiles will be driven off through evaporation, and I will have fully dried bottles for dispensing into. I don't use a rinse aid or a detergent on those cycles.

 

[davidabcd]

I am one who likes to bottle with bottles that are freshly pulled from the sanitizer solution and shaken out the best that I can. The problem was that I was using unfiltered tap water as the makeup water for the sanitizer and that does have chlorine in it.

I'm not new but there are always brewing questions. A question regarding the "shaken out" part: would leaving them to drip-dry fairly well counter what you experienced? I use tap water (Detroit) and haven't had a problem yet; however, on occasion I have smelled a bit of chlorine from the tap.

 

[mabrungard]

I haven't left bottles to drain or dry out, so I can't comment on the effect. But I expect that it would be beneficial in reducing the accumulation of chlorine and the subsequent dichlorophenol in the bottle.