I'm new to this forum but have been all grain brewing for 6 months or so. Since I made the move to all grain I have noticed a definite flavour flaw in most of my brews. If I was asked I'd say it was the cardboard/papery flavour of oxidation but it's hard to say. I'm having trouble getting rid of it and think it might be due to hotside oxidation in the mash because I didn't notice it when I used extract.
I'm using an insulated water cooler as a mash tun and batch sparge with a 35 litre pot on a gas hob as a kettle. I'm leaning towards wort recirculation and clarity as the cause but really not sure at all.
Any help would be greatly appreciated
Flavour Flaw
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PieOPah
Sorry I can't be much assistance but one thing I will say is that it is unlikely to be due to HSA (Hot Side Aeration). I believe that many people have purposefully attempted to ruin a beer by splashing their hot wort around. It is likely that this is only a problem on a huge scale and not something for us home brewers to worry about.
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hendrixcat
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Matt
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hendrixcat
The worst one was an APA attempt:
4.5kg Maris Otter
450g 75L Crystal
30g Northdown 60 mins
20g Amarillo 20 mins
20g Amarillo 5 mins
I mixed up my yeast and used Safale T58 By mistake which gave it peppery tones I wasn't expecting.
It's also in another ale much the same but with Northdown and heaps of Styrian Goldings and Gervain English Ale Yeast
An Irish Red has hints of it also, but less prominent.
4.5kg Maris Otter
450g 75L Crystal
30g Northdown 60 mins
20g Amarillo 20 mins
20g Amarillo 5 mins
I mixed up my yeast and used Safale T58 By mistake which gave it peppery tones I wasn't expecting.
It's also in another ale much the same but with Northdown and heaps of Styrian Goldings and Gervain English Ale Yeast
An Irish Red has hints of it also, but less prominent.
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SteveD
If it is oxidation, you can rule out cold side oxidation as you say you didn't get it with extract, and after the mash and sparge, the processes are the same. HSA might be to blame. There are very experienced homebrewers who maintain that it is relevant, and I don't think many of the top guys let their mash wort splash about too much if they can help it. Another source of HSA is running from the mash tun into the boiler or underback via the tap and an airborne drop. That's one way to aerate a wort! Use a pipe to run off from the mash tun and into the boiler with a minimum of splashing, as if you were racking from fermenter into barrel. Try that, together with minimum hot wort splashing in general, and see if it makes a difference. It did to mine.
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steve_flack
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UserDeleted
Splashing hot wort around is not (necessarily) a cause of HSA.
Mistreatment of the MASH is much more likely to be a cause, which cause the precursors of trans-2-nonenal to be formed. Its much more likely to appear over time in lighter beers rather than darker ones as darker beers contain a large amount of natural anti oxidants.
There are two pathways to t2n production, one involving oxygen, but the other depends on the amount of lipase and lipoxygenase in the malt (controlled by malting and mashing) the amount of these enzymes that make it through the boil (they are thermally labile) directly affect the t2n potential of the beer.
The flavour threshold of t2n is incredibly small ~0.1ppb, and very few drinkers are insensitive to it.
So treat the mash gently, during stirring, and any transfer for lautering and sparging, and ensure that you get a good rolling boil to help destroy the enzymatic pathway. darker kilned malts have lower amounts of the lipase enzymes in general.
Mistreatment of the MASH is much more likely to be a cause, which cause the precursors of trans-2-nonenal to be formed. Its much more likely to appear over time in lighter beers rather than darker ones as darker beers contain a large amount of natural anti oxidants.
There are two pathways to t2n production, one involving oxygen, but the other depends on the amount of lipase and lipoxygenase in the malt (controlled by malting and mashing) the amount of these enzymes that make it through the boil (they are thermally labile) directly affect the t2n potential of the beer.
The flavour threshold of t2n is incredibly small ~0.1ppb, and very few drinkers are insensitive to it.
So treat the mash gently, during stirring, and any transfer for lautering and sparging, and ensure that you get a good rolling boil to help destroy the enzymatic pathway. darker kilned malts have lower amounts of the lipase enzymes in general.
I can't say I've ever noticed this in my beer, despite the fact that I take no precautions whatsoever against HSA while mashing or boiling.
Could this be happening later in the process? Maybe you should review your bottling/kegging procedures? It's possible that you're only noticing this now due to the otherwise clean flavour of the grain brew. Just a thought.
Could this be happening later in the process? Maybe you should review your bottling/kegging procedures? It's possible that you're only noticing this now due to the otherwise clean flavour of the grain brew. Just a thought.
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hendrixcat
Unfortunately the taste is quite evident straight from the primary. I've read up about T2N and lipoxygenase for my course at Heriot Watt but the theory doesn't seem to be much use to me if I can't get it to work in practice.Could this be happening later in the process? Maybe you should review your bottling/kegging procedures?
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Andy
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When I used to collect my sparge runnings in a bucket and pour the full bucket into the boiler I had a few brews develop a similar subtly unpleasant taste. These days I pump the mash output into the boiler and try to minimise splashing/agitation of the mash and sparge output. Haven't had the off taste since then.
Dan!
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SteveD
Apart from the reasons you mention, rough or prolonged stirring of the mash can increase the likelyhood of a set mash as you break up the grain and release more flour (farinaceous material) into the wort. I used to stir and stir to break up lumps and even out the temperature. Overdid it. Consequently I got a fair few set or slow run off mashes until I mentioned it to Norman of the Art of Brewing. He said minimise the stirring. Hey presto! No more set mashes! The most recent one did set, but, I had to stir that quite a bit when adjusting the temp with hot water.UserDeleted wrote:
So treat the mash gently, during stirring, and any transfer for lautering and sparging
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SteveD
It may be possible that there's a temperature factor as well. Your wort would be cooling down if you collect in a bucket...then you slosh. Cooler wort admits more oxygen. Wheeler is adamant; do not let your wort cool during run off and collection. Off-tastes could result.Andy wrote:When I used to collect my sparge runnings in a bucket and pour the full bucket into the boiler I had a few brews develop a similar subtly unpleasant taste. These days I pump the mash output into the boiler and try to minimise splashing/agitation of the mash and sparge output. Haven't had the off taste since then.
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Vossy1
