Troubleshooting chlorophenols & band-aid burps

[Holy_Hops]

Hey all.

So the last two batches I've made have given me band-aid burps.
The first was a Kolsch & the most recent is a Double IPA.

I can only pick up the off-flavor via band-aid burps (and it's really only every 3 burps, anyway). It isn't anything super noticeable and both beers turned out pretty well minus the plasticy aftertaste on a few of the burps. It's a fairly minor flaw that only I notice, but it's driving my OCD brewer side nuts.

After a lot of forum searching I'm scratching my head on this one. I use only RO water in the mash & sparge. I also don't *think* it's an infection. For both beers I pitched a nice starter (2 liters of WLP029 on the Kolsch & 2 liters of WLP007 on the IPA) and they took off right away with expected final gravities.

Two possibilities entered my mind...

When I rinse & sanitize my plastic fermenting bucket I use Star San with water coming from a shower-tap hose hookup I have in my basement. I do the same for rinsing & sanitizing my kegs - it's all tap water.

Would the little bit of Star San foam made from tap water give off enough chlorophenols for a 6 gallon batch?

The other possibility is that I accidentally used tap water for my 2 liter starter on each & did not decant at all. I just dumped the entire starter wort into the batch on the brew-day & let her fly.

I'm leaning towards the latter as the culprit and will use RO water in my starters from here on out, but was wondering if you all treat your Star-San & rinse water with Campden tablets as well.

Thanks in advance for any pointers!

 

[biertourist]

Hey all.

So the last two batches I've made have given me band-aid burps.
The first was a Kolsch & the most recent is a Double IPA.

I can only pick up the off-flavor via band-aid burps (and it's really only every 3 burps, anyway). It isn't anything super noticeable and both beers turned out pretty well minus the plasticy aftertaste on a few of the burps. It's a fairly minor flaw that only I notice, but it's driving my OCD brewer side nuts.

After a lot of forum searching I'm scratching my head on this one. I use only RO water in the mash & sparge. I also don't *think* it's an infection. For both beers I pitched a nice starter (2 liters of WLP029 on the Kolsch & 2 liters of WLP007 on the IPA) and they took off right away with expected final gravities.

Two possibilities entered my mind...

When I rinse & sanitize my plastic fermenting bucket I use Star San with water coming from a shower-tap hose hookup I have in my basement. I do the same for rinsing & sanitizing my kegs - it's all tap water.

Would the little bit of Star San foam made from tap water give off enough chlorophenols for a 6 gallon batch?

The other possibility is that I accidentally used tap water for my 2 liter starter on each & did not decant at all. I just dumped the entire starter wort into the batch on the brew-day & let her fly.

I'm leaning towards the latter as the culprit and will use RO water in my starters from here on out, but was wondering if you all treat your Star-San & rinse water with Campden tablets as well.

Thanks in advance for any pointers!

Chlorophenols almost always have their root cause in chlorinated water that hasn't been treated; your use of RO water SHOULD address chlorophenols unless something is seriously wrong.
-How old is the RO system?
-When did you last change the membrane?
-Have you tested the water coming out of your RO system recently for chlorine?


Obviously chlorine-containing sanitizers are a close second root cause of chlorophenols in chlorine containing water. -No equipment has touched bleach or other chlorine-based sanitizer, right? -Not washing yeast with chlorine tablets, right? (insanely rare for homebrewers; standard practice for large micros after several generations; acid washing is so 10 years ago)


Assuming that your RO system isn't failing to filter everything out: How do you know for sure that what you're tasting is CHLOROPHENOLS and not just regular phenols?

Kolsch and any ale yeast that would typically be used in an IPA/ DIPA shouldn't have the gene necessary to create phenolics (most brewing strains don't have the gene), so this makes me inclined to think it's not coming from your primary yeast strains.

-I hate to say it but this definitely leads us into the direction of infection very quickly if you know your RO filter is working properly and you haven't ever used a chlorine sanitizer. But that also probably means that this just a regular phenolic and not a chlorophenol, not that that technical detail makes your beer taste any better.


StarSan won't give you chlorophenolics.
I doubt that the level of chlorine that you get from using tap water in a starter would end up even close to the taste threshold, too.

RO membrane, chlorine sanitizer used in the past on SOMETHING, or infection; in that order.


Adam

 

[Minbari]

dont forget Chloramine. RO membranes do not filter them.

 

[Holy_Hops]

Thanks for the thoughtful reply, biertourist.

Normally I use grocery store RO water. Now that I think about it, on the Kolsch & IPA I used our home RO water tap on the sink. The filter on that def. needs to be replaced as we haven't done it in a year or so.

I also brewed an American Pale Ale in between those batches using the same equipment and got no phenols. The only difference was using the grocery store RO as opposed to our home one.

I'll change our home filter & give it a go on my next batch. Thanks for the pointers.

Cheers