Medicinal taste in two recent batches of pale ale

[Elyob Tap]

Hi, I'm a reborn AG home brewer in the last six months having invested in a Grainfather. Previously (2008 - 2011) I brewed on a 40L home built system.
Anyway having brewed maybe 7 or 8 batches on the GF, two recent batches have ended up with a medicinal flavour (Chloroseptic spray) one dumped today and the second not as bad as the first was kegged today.

From what I can research it is likely caused by one of the following:
(1) Phenols`
(2) Bacteria
(3) Sparging too hot above 76C
(4) Sparging after run off gets below 1.010
(5) Chlorine

I use stainless steel FVs with thermowells for fermentation temp control.
I haven't been using an airlock during fermentation (a close fitting lid), but the flavour is not indicative of oxidisation anyway.
I prepare my water (50L) in advance of each brew adding one campden table crushed to the water.
I add salts based on an old water report I have from around 2009.
I haven't been checking pH as I didn't have any buffer solution (received this week and testing will commence going forward).
I have no way to check sparge run off gravity as you cant do this with the GF. I have been letting the grain bed drain until it stops pretty much. Maybe this is the problem.
I also haven't removed the thermowell and tap when cleaning the FVs.
I used milton initially as a sanitiser for the the FVs but moved to Chemsan prior to the issue occurring the first time. I spray the FVs to coat well and then drain prior to use without rinsing.
I have a temp controller on my sparge water heater set to 75c so I don't think this is the issue.
I have ordered a small RO system, and intend to remove taps and thermowells etc before use the next time
Fermentation takes place at 18.5C +/- 0.5 in fermentation chanber that I built.

Long post I know but I wanted to include as much detail as possible.
Any similar experiences, thoughts and advice greatly appreceiated.

[Pheeel]

I doubt it's due to 3 and 4. It's almost certainly because of 2 or 5 and I'd bet its 5. But seeing as you're going with a Camden tablet it's possible it's not. I'd try it with the RO bit don't change anything else about your process to keep the other variables the same

[DEMPSEY]

I'd say 5 is the most likely. grainfather water volumn is usually bang on but you can easy get a last run off the sparge to satisfy that number using a refractometer. when sparge is finished I sit the grain pipe on a white bucket lid and enough wort drips out to get measurement. I find taking copious notes on brew day is great as often its months since you have brewed and memory is not great.

[Elyob Tap]

Thanks for the feedback.
I tend to agree that 3 and 4 (sparging) is unlikely the issue given the temp control and that GF have the volumes worked out most likely to prevent low gravity last runnings.

1, 2 and 5 are my targets. I also just read that water supplied through a garden hose can contribute by picking up vinyl and phenolic flavours. I connect my garden hose to an inlet in my shed for water supply. I used to use a special short hose length for this back in the day (2008), but got lazy this time around and just connected my long 30 metre hose up.
I just realised too that I don't flush the hose before using so water could be sitting in the coiled hose for weeks and then it goes into my beer (doh!). I sure as hell wouldn't drink it.
Interestingly, I brewed twice last weekend saturday and sunday. The saturday beer has the problem and the sunday beer is fine. This could support the hose theory.
A new dedicated piece of water supply hose required immediately.
So new hose, sanitisation check and RO system and lets see how next brew goes.

[DEMPSEY]

Change one thing. That what the dentist said. By changing one thing at a time and recording it you eventually get to the cause.

[Elyob Tap]

Change one thing is all very well and as an engineer that would normally be my philosophy, but I can't afford to waste two batches eliminating two things if I don't eliminate the right cause the first time. Pouring 40L of beer down the drain for science is not my bag
Given that I use campden tablets the chlorine should not be the issue, so that leaves phenols (garden hose?? x yeast) and bacteria (sanitisation).
The sanitisation is good I think so changing the water supply hose is the obvious choice for me. Ironically, the hose I run from my chiller outfeed to drain is the food grade hose i used to use for water supply to HLT. It will be returning to proper service for next brew.

[LordEoin]

6) bad ingredients.

I had the same at one point and couldn't figure it out for ages. I had some dodgy grain.

[pob]

I connect my garden hose to an inlet in my shed for water supply ... but got lazy this time around and just connected my long 30 metre hose up.
I sure as hell wouldn't drink it.
Interestingly, I brewed twice last weekend saturday and sunday. The saturday beer has the problem and the sunday beer is fine. This could support the hose theory.

It is probably definitely sitting water in hose that is contaminated that is causing the issue.

For the next batch can you just fill the GF & HLT (sparge heater) with a clean/new bucket not using the hose.

If it's not drinkable water, don't let it near your system.

[Elyob Tap]

I finally got to the bottom of this issue.
It turns out it was contamination in the FV tap.
I removed the the garden hose from the equation and still had the problem.
I bought and installed an RO kit which I partially abandoned during first use. The amount of waste water to RO water was more than my conscience could live with (on top of chilling water). I bypassed the RO filter and just used the other two filters.
I removed the FV tap after my normal cleaning process one day only to find yeast residue in it.
I thoroughly cleaned it and reverted to ensuring the tap was submersed in sanitiser when sanitising. I had changed to giving it a quick spray around the time the issue started.
Now the tap comes off for inspection prior to brewing and once replaced on the FV tap is always immersed in sanitiser.
I lost three consecutive batches to this issue. The off flavour was pointing me to everything except sanitisation until I read an article that said 'any of the above can cause the medicinal taste'.
It goes to show its not always what you think.
10 years ago I brewed probably 50 batches (half 40L size) and only ever had one infection and that was due to using a piece of unsanitised string to tie a dry hop muslin bag.

Brewer beware!

[Emot]

(4) Sparging after run off gets below 1.010

I have to admit this is the first time I've come across this as something I should be doing! How do you all monitor this? I batch sparge so I'm not sure if this is even possible. I use Beersmith to work out volumes of water which looks like 2.6l/kg + some number it comes up with. Do I just hope that Beersmith gives me the correct sparge volume and if not, adjust so that my sparge water is >1.010?

[nigel_c]

As long as mash & sparge water ph are correct you will not extract anything from over sparging.

[delzep]

I use this to calculate water amounts

https://www.jimsbeerkit.co.uk/batchcalc.php

[stevosan]

Yeah I have a few plastic fermenters with the cheap plastic taps but decided to just buy new ones without as I dont like thinking the beer is inside the tap during the ferment. just go with racking to keg now through a siphon. Good catch!