Brewing has gone downhill!

[DarrenSL]

I have made c.20 AG brews to date with great success. Generally my brews have been significantly better than most commercial offerings. However, more recently things have gone downhill and I have had several very poor batches now all with the same distinctive smell and taste.

I cannot find anything that accurately describes the smell (although I would love to know what cooked corn or horse blankets actually smell like!). It has a hint of dark roast malt (despite using only MO or lager malt + light crystal) and has a cabbage undertone. The taste lingers on the back of the tongue and leaves a slight acridity on the tip of tongue for some time afterwards. All the brews over attenuated (e.g. Mysterios SNPA finished at 1.008 86%, Galaxy Delight at 1.009 83%). Over time the beers get progressively worse over 2-3 weeks to the point of non drinkability.

My santisation is overkill (I think):
All equipment is fully dismantled and soaked in hot percarbonate solution overnight.
Everything is rinsed thoroughly
Immediately before use everything is thoroughly doused in fresh Star San

My equipment has been changed as well. I am currently fermenting in a SS brewbucket in a fermentation chamber at 19-20C. The only post boil equipment that is consistent is a 1m piece of silicone tubing and a straining bag that I use to filter while transfering to the fermenter. Suspecting the silicone tubing, I boiled this for half an hour before use on my latest brew but to no avail. The bag is soaked in starsan before use.

Other possible culprits??
I don't trust my wort chiller. It's often black with oxide. I wipe down with neat starsan before use and immerse (empty) in the boiling wort for 15 minutes (is this enough to kill everything!)
When chilling, I cover with the (starsan sprayed) boiler lid and aluminum foil around the gaps to prevent flies or dust getting in. This creates condensation, some of which drips back into the wort.

Hope someone can help

Thanks

[johnrm]

I feel your pain.
I had a series of off beers a while back.
I went back to basics - a medium strength bleach soak first for Everything, a good rinse then follow with your normal routine.
It solved my problems.

[boingy]

When chilling, I cover with the (starsan sprayed) boiler lid and aluminum foil around the gaps to prevent flies or dust getting in. This creates condensation, some of which drips back into the wort.

That may be where your cabbage is coming from. DMS can form during cooling and cabbage taste is a DMS symptom. Cool with the lid off.

Your attenuation and the quick degeneration of the beer is suspicious too. What yeast do you use and how to you prepare it?

[DarrenSL]

Yeah I did think about the risk of DMS condensate getting back into the beer but figured the risk of a fly or other debris getting into the beer was riskier (I brew outside on a gas burner).

The yeast in the examples above is Malt Millers West Coast dry yeast hydrated in pre boiled water before use. I got the same problem with WLP023 (Burton Ale) yeast as well.

The over attenuation could possibly be a red herring as most of my beers attenuate high. I use BIAB 20-22L mash. A combination of low temperatures (66 dropping to 64C), thin mash and prolonged sparging/rinsing times is probably contributing.

[Wonkydonkey]

I think boingy is right, have you ever gone pass a field with cabbages that have gone over ( started to rot)
Smells worse than an old lady's smalls. Not that ive had a sniff lately. I got over that fetish.

No really you don't need a lot of DMS to taste/smell it.

If you have to cover your brew while cooling, go and get an off cut of net curtain, it will do the job as a fly screen,

Ps it never hurts, to give your kit a spring clean, just tobe sure you have not over looked anything that needs a clean.

[Dave S]

The only thing you haven't mentioned in the clean routine is the fermentation chamber. I'd give it the once over to make sure there's nothing lurking. But cabbage - yes, DMS is a likely culprit.

[DarrenSL]

Thanks for the replies guys. Some definite food for thought.

Looking into DMS, it continues to be produced after flame out. It is quite plausible that it is still boiling off, hitting the lid, condensing and dripping back into the wort. It might also explain why my beers have suddenly deteriorated, i.e. the lid is colder at this time of year and so capturing more condensate.

What I don't get is
(i) given the intense aroma that DMS has (detectable at parts per billion range) I would expect to get a whiff of the stuff as soon as I lift the lid off. Although it could be that at high concentrations the smell cannot be detected (same as hydrogen sulphide)
(ii) When I take my OG hydrometer sample I always give it a smell and taste test and have never detected any DMS.
(iii) The beer tends to get worse over time (could be due to loss of hop aroma so the DMS becomes more pronounced).

Either way, it is clearly bad practice to put the lid back on while cooling so going forward I will be using a piece of voile.

I will be replacing the silicone tubing as well to eliminate that as a possible source of infection.

I'll give the fermentation chamber and all my equipment a good clean as well. I would have thought that percarbonate followed by a starsan wash would kill almost everything. Is there anything I could use that is more powerful! Perhaps neat bleach?


Thanks

[orlando]

I would look a little closer at the plate chiller. These are notoriously difficult to keep spotlessly clean and running boiling wort through it for 15 minutes is usually fine but if it isn't rigorously cleaned afterwards it presents a lovely warm, moist, sugar filled vector for bugs. I think you should try some serious degunking of it and put it in a pressure cooker at 15 p.s.i for at least 20 minutes after a thorough rinsing. Worst infection I ever got was with a dirty plate chiller. My routine with it now is serious but never being able to see what lurks in there probably gives these things only a certain number of years before replacing. The high attenuation can be down to a wild yeast infection, a plate chiller provides a great opportunity for spores to survive boiling wort and continue on into the beer.

[GrowlingDogBeer]

I would look a little closer at the plate chiller. These are notoriously difficult to keep spotlessly clean and running boiling wort through it for 15 minutes is usually fine but if it isn't rigorously cleaned afterwards it presents a lovely warm, moist, sugar filled vector for bugs. I think you should try some serious degunking of it and put it in a pressure cooker at 15 p.s.i for at least 20 minutes after a thorough rinsing. Worst infection I ever got was with a dirty plate chiller. My routine with it now is serious but never being able to see what lurks in there probably gives these things only a certain number of years before replacing. The high attenuation can be down to a wild yeast infection, a plate chiller provides a great opportunity for spores to survive boiling wort and continue on into the beer.

He has an immersion chiller, which he wipes with neat starsan.

Personally I wouldn't bother wiping the immersion chiller with Starsan, infact I would not use neat starsan on anything, thats not how it is meant to be used. Just rinse off any dust off of the chiller before putting it in the boiler.

[timbo41]

Just wondering and throwing it out there.....what yeast are you using. Although dms seems most likely, as all above have said, I have found that using dry yeasts particularly old packs gives a vegetal sulphury tang to brews...yes I know that some do, but a few brews I've done with wilkos gervin and danstar notty have had that effect to my pallate

Edit sorry just re. Read original post.... So its probably not the yeasts. What strikes me is that both the recipes you mention are likely from MM . Perhaps Rob might have some ideas....although I very much doubt there's been any change in these well known and respected mixes

[DarrenSL]

Thanks again.

Was thinking of getting a plate chiller next but need to sort out the basics first and get back to brewing decent beer!

I've used MM loads in fact this is my 5th batch of SNPA. Everything prior to January this year has turned out fine other than an experimental batch using recovered yeast and various left over hops and malt. Even that was drinkable despite ending at 1.004!

All facts considered I think DMS but my worst fear is stubborn resistant wild yeast so I would like to do an intensive clean and sanitisation to be sure. Anyone got any spare cobalt 60

[boingy]

1.004 makes me wonder if your hydro is accurate.

[Fil]

i dont know if its relevant, but my IC chiller always exited the brew a lil brighter than it went in, but was never black!,, i did try cleaning some copper bits in hot citric acid and that tube went black??

imho the chiller should just be clean, no need to sanitise in advance of plunging into the boil, to remove the black, probably due to the strong acid wash? a bit of wire wool will soon scrub it off, and a cold water rinse should be all you need to do before use..

fwiw i too have had a few less than spectacular brews of late, ever since upgrading to a bigger brewkit, im hoping its just a case of working with new equipment and refining the techniques now used. tho i am now adding some copper back into the kettle after investing in 100% ss pots bits n fittings - HA!

[orlando]

He has an immersion chiller, which he wipes with neat starsan.

Personally I wouldn't bother wiping the immersion chiller with Starsan, infact I would not use neat starsan on anything, thats not how it is meant to be used. Just rinse off any dust off of the chiller before putting it in the boiler.

Agh, didn't twig that, well he can forget all that advice until he gets one. Neat Starsan is not a good idea and a waste.

[DarrenSL]

That's the first thing I thought Boingy but no, the hydrometer is spot on. The problem with that particular brew was that I had harvested yeast for the first time (WLP007). I thought it was a good idea to take a bit of the less flocculant layer only (most active being my reasoning) and build a starter. That, coupled with my general over attenuation problem led to my super dry beer. But that's for another thread ("what can I do about my over attenuation problem!")

I may be a bit overly worried on the chiller. I tend to go way over the top on sanitisation but the chiller was being overlooked. I just pull it out when finished and leave it on the patio until I get round to quickly hosing off and sticking in the shed. I thought if there is anywhere that wild yeast or any bacteria are going to love, then its my used chiller. Btw, it comes out of the wort nice and clean Just goes black when it gets oxidised.

Back to my latest brew... I've just poured a glass and drank with a view of DMS not infection. It's amazing what tricks the brain plays. It's actually not a bad beer when you cut through the cabbage Time to try CO2 scrubbing!