Campden Tabs, Chlorophenols and Precursors in Dark Grains

Over the last 10 batches or so, I switched back from RO to my local Austin water. While mostly low mineral and relatively low alkalinity, Austin water reports usually show more than 2.8 mg/L of Chloramines.

To combat this, I’m using a carbon block filter and then Campden tablets at the package recommended dosage (1/2 tablet per 10G of water).

My lighter beers seemed to be fine with this, but I’ve had feedback from trusted BJCP certified tasters on beers with more roasted grains (i.e. Bock) suggesting that there’s a Chlorophenol issue. I do detect something off, though I would not have immediately picked it out as Chlorophenol .

A few questions:

  1. Has anyone seen good info on the amount of Campden required to neutralize a certain amount of Chloramine?

  2. Has anyone noticed a change in the character of Chlorophenols in beers with more roasted grains?

  3. If it’s not a character thing, is it possible that somehow beers with more roasted grains have more precursors and are more likely to display Chlorophenols with the same level of residual Chlorine/Chloramine present?

It seems that simply adding a full Campden tablet would likely solve the problem. However, I’m also curious why this issue isn’t obvious in other beers. Maybe it’s a coincidence, but id there’s a relationship there it seems worth understanding.

I think you might be asking a lot of the right questions!  My experiences on this are a bit vague, but I do seem to detect a higher probability of chlorophenols in darker beers, and I must admit I have even experienced very very slight levels of chlorophenols in my beers with the “regular” dose of 1/4 Campden tablet in 5 gallons.  Perhaps it truly, truly is time to step up the Campden and use more, just to see if that helps.  I really don’t think it will hurt anything.  Why aren’t we using 1/2 Campden for 5 gallons or a whole Camden for 10 gallons?!  It’s cheap and effective!  Maybe more really is better!!!

I don’t use Campden tablets, but I have noticed that the stuff does not readily dissolve in water.  Are you giving the Campden tablets enough time to dissolve and work?

They dissolve pretty quickly.  Crushing is important though.

I use a whole tablet of campden for five gallons, primarily because I am too lazy to cut a tablet. I had raised the question whether this was too much and seemingly on this forum, it was the consensus that it did not really matter. Anyway I have never received any complaints about my darker beers. Perhaps I was addressing a problem without realizing it.

Are the darker grain beers “registering” phenolics along the lines of light smokiness or straight up medicinal/plastic/bandaid?

  1. one tab per 20 gal. so you’re god there
  2. Nope
  3. Not that I’m aware of

Have you tasted the chlorophenols yourself?  How many people have?  How much roasted grain are you putting in a bock?  Can you tell I’m skeptical?  :wink:

Perhaps more likely you are seeing other changes in the beer due to different water chemistry. I’d suspect you’re seeing greater tannin extraction due to incorrect sparge ph and/or pulling ashy flavor out of roasted grains again due to water chemistry issues.

My typical procedure is to filter and salt the water about 24 hours before brew day. I do crush the Campden tablet prior to stirring it into the water. Also, on brew day I use my pump to recirculate the water as I approach strike temp and then pump it into my mash tun, so it should be plenty stirred and should have had plenty of opportunity to dissolve by that point.

My understanding is that with modest stirring, Campden should get the job done almost instantly. My only concern in reconsidering this is that maybe if I stir in the Campden and then immediately put the lid on the cooler, I’m somehow inhibiting the process?

Mash pH on this one was 5.25. I’ve made that mistake before and I know that taste, but this is something a bit different.

I was wondering if larger amounts of chloramine would somehow require more than the recommended dosage to fully neutralize. It may be that the difference between 2ppm and 4ppm chloramine only requires and extra 1/16 of a tablet, but I’ve never seen any info on how to check that.

I taste something “pool like”, but not the classic plastic/band-aid/medicinal thing (which I did have in some very early attempts to use my the local Austin water). When I first started all-grain I was using RO. For the last several months I’ve been brewing with the local water just filtered with carbon block and using Campden to attempt to neutralize all the chloramine. I’m not sure if this is just a lower-level presentation of the same thing, or some other issue. I did end up adding some chalk and baking soda to the kettle as I undershot my desired pH a bit in the mash (5.25 but I’ve discovered I prefer 5.4 for this beer). Given the opportunity for a do-over I would probably not try to “fix” that.

This beer is on the most recent episode of Brewing with Style, so the folks that detected it were JP, Tasty, Jamil (and I believe one other guest brewer). I think the podcast is posted this week so I’ll be able to listen to the comments again. Now that they’ve pointed it out, it sticks out to me like a sore thumb. Before I knew there was something I didn’t like about that beer, but couldn’t really place it.

Here’s the recipe – relatively low on roasted malt, but more than my other beers (brewing a lot of lighter beers lately):

Brew Method: All Grain
Style Name: Dunkles Bock
Boil Time: 90 min
Batch Size: 6 gallons (fermentor volume)
Boil Size: 8.25 gallons
Boil Gravity: 1.052
Efficiency: 62% (brew house)

STATS:
Original Gravity: 1.072
Final Gravity: 1.019
ABV (standard): 6.93%
IBU (tinseth): 21.75
SRM (morey): 21.88

FERMENTABLES:
11 lb - Avangard Munich (61.1%)
5 lb - Best Malz Pilsener (27.8%)
8 oz - German - CaraMunich III (2.8%)
8 oz - American - Caramel / Crystal 120L (2.8%)
8 oz - United Kingdom - Extra Dark Crystal 160L (2.8%)
8 oz - German - Melanoidin (2.8%)

HOPS:
16 g - Magnum, Type: Pellet, AA: 12.4, Use: Boil for 60 min, IBU: 21.75

MASH GUIDELINES:
1) Infusion, Temp: 153 F, Time: 55 min, Amount: 6.5 gal
2) Sparge, Temp: 165 F, Time: 20 min, Amount: 4.5 gal
Starting Mash Thickness: 1.5 qt/lb

OTHER INGREDIENTS:
0.5 each - Campden tablet, Time: 60 min, Type: Water Agt, Use: Mash
5 g - Calcium chloride, Time: 55 min, Type: Water Agt, Use: Mash
2 g - Calcium sulfate, Time: 55 min, Type: Water Agt, Use: Mash
2.42 ml - Lactic acid, Time: 55 min, Type: Water Agt, Use: Mash
2 g - Calcium carbonate, Time: 90 min, Type: Water Agt, Use: Boil
2 g - Baking soda, Time: 90 min, Type: Water Agt, Use: Boil
0.5 each - Whirlfloc, Time: 15 min, Type: Fining, Use: Boil
1.25 tsp - Yeast nutrient, Type: Other, Use: Boil

YEAST:
White Labs - German Bock Lager Yeast WLP833

I do believe it is important to let the treated water offgas in the open for at least 5 or 10 minutes.  But that is just a hunch at this point – I have not looked up the actual chemical reactions.  If chlorine gas needs to escape but is trapped, this could be a problem.

+1;  Acidify sparge?  If not, I’d say that’s it.  Honestly though, I find it best to stick to RO (I prefer distilled) for lagers and I HATE paying for it but I get much more authentic results than treated tap.  If this is the issue, then you have an issue with POLYphenols.  Good news is, it is easy treated with polyclar.

Yes, 2.4mL of 88% lactic. That was actually almost twice as much as I intended, so the mash pH was 5.25 rather than the 5.4 I was targeting.

As I mentioned above, I’ve tasted the polyphenol harshness from a high pH mash/sparge, and it’s not that. I’m not really sure how to describe it except that it tastes a little like pool water – maybe even plastic-like? It’s not the over the top Band-Aid / Chloraseptic thing (I’ve made that beer before too, so I know what that tastes like), unless it’s a low level of that flavor interacting with something in this beer to make it taste different.

If I didn’t know better, I’d assume that I left a quart of chlorinated pool water in the bottom of the keg and then racked the beer on top of it.

I am not fully versed on chloramines but I do think there can seasonal variance and water treatment may require more than tested.  Heavy rain, drought, etc.  Something to keep in mind.  Also, too low of pH can present similar off flavors like too high pH and even though you later raised you might have managed to extract some funky stuff.  All this being said your overall process/etc looks good and is a puzzler for sure.  Best of luck.

So the good news is I kegged a rebrew of this beer last night. It’s only 3 weeks old and uncarbonated, but the sample was smooth and did not show any of the off flavor discussed here.

The bad news is that I rebrewed this before I posted this question, so I changed several things with this batch (but not actually the Campden). That will make it harder to pin down exactly what happened. Relevant differences are as follows:

Good Bock

  • 5.4 mash pH
  • 1.2mL lactic added to sparge
  • No mineral additions
  • Hit strike temp of 155
  • 81% conversion efficiency

“Chemically” Bock

  • 5.25 mash pH
  • 2.4mL lactic added (half each to mash and sparge)
  • Minerals: 5g CaCl (mash), 2g CaSO4 (mash), 2g CaCO3 (kettle), 2g NaHCO3 (kettle)
  • Initially overshot strike temp of 155 by 4 degrees, took 15 mins to cool from 159 to 155
  • 78% conversion efficiency

Both batches were treated with half a Campden tablet in 11G of water. It’s possible that the chloramine content was drastically different between March and now due to some shock treatment the water utility was doing.

However, it seems more likely that the low mash pH and/or the minerals were contributing to the off flavor. I’ll update if any more data comes in, but otherwise it looks like I’ve learned all I can from this one.

Good to hear you are back on track. Nothing more frustrating than trying to isolate the cause of off-flavors in a beer made at home. So many variables and equipment in play that need to be looked at.

+1  RDWHAH

Stupid me. I think I know exactly what this was. Looking back at my logs I realized that I waited too long in between batches to do a straight repitch, so I made a “revival” starter to get the yeast going.

While my usual practice is to use distilled water for starters with DME, it appears that on this one I didn’t. My notes don’t mention anything about putting Campden into the starter water, so I probably just pulled it from the fridge filter.

Diluted into a 5G batch, the 2L of Chlorophenol laden starter wort was not as obvious as having the same issue with the full batch, but I’m almost certain that’s where this off flavor is coming from.