A variant of the metallic off-taste ussue

[robgoch]

Mindful that I'm treading on a comparatively well-blogged area (-I think I've been through relevant posts without any pointers) but I feel I have a twist on the 'beer tastes metallic' situation. I've mainly been a kit / partial-mash brewer but started my first all-grain brew, a dark mild in January: I let the mash run longer than the 1 hour suggested, and unfortunately took ages getting to pitch temp, so room for a few issues there. I also hit a stalled-at-1020 issue, and had to re-rouse a fair bit before reluctantly bottling at a higher FG than I would have liked: anything to save the brew etc.

Step forward 4 weeks, and the first samples pour well with a good head, but taste like coins in water, and smell like raw liver ! I haven't picked up other signs of yeast infection: no wet-card, no solvent odours or the like. The only metal of any sort in my kit is the basic kettle element in my plastic boiler, and a more recent brew suggests that this isn't damaged and leaching metals into the brews. Has anyone else encountered that combination of off-taste and odour?

 

[Agentgonzo]

I appear to be in the minority, but I get slight metallic tastes from oxidised beer. Normally it happens if I've been putting it in a cask or minikeg and it's been open for a couple of days. To my palette, it comes across as metallic before it goes into vinegar flavours - and definitely that copper/metallic taste you get on your hands if you've been handling coins. I've had this in pubs a very few times as well. I don't know what raw liver is like.

But never had it in bottles/fresh keg, so this may be different from what you're experiencing.

 

[robgoch]

Thanks, AgentGonzo: I might be overelaborating (!) with the liver odour, but it IS the first thing that comes to mind, ie opening a supermarket meat packet. The metal taste is a back-of-mouth thing that isn't the first sensation: it's almost coffee-ish at first, which has lead me to thinking the brew has worked. But then the metal takes over and takes the edge off. I can't discount oxidation: I was stirring it furiously after adding more sugar (-tho no extra yeast or nutrient: that might be an omission ?) when the fermentation seized. I've never knowingly lost a brew to infection either (-altho' I've probably finished a few near the edge years ago !) so I'm still not sure what I'd be looking for: but I don't think I've seen the 'classic' signs. That said, dark mild in pubs often tasted 'metal'-y when I first started drinking: thinking particularly Whitbread Mild here, so it might actually be a feature. But not at this level of taste, I think. I DID read a comment about it being possible to overload the wort with iron molecules, which might be a result of my prolonged mash. My main concern is throwing away beer (-perish the thought !) if it might actually mature given time: but I can't see this flavour disappearing easily.

 

[foxy]

Mindful that I'm treading on a comparatively well-blogged area (-I think I've been through relevant posts without any pointers) but I feel I have a twist on the 'beer tastes metallic' situation. I've mainly been a kit / partial-mash brewer but started my first all-grain brew, a dark mild in January: I let the mash run longer than the 1 hour suggested, and unfortunately took ages getting to pitch temp, so room for a few issues there. I also hit a stalled-at-1020 issue, and had to re-rouse a fair bit before reluctantly bottling at a higher FG than I would have liked: anything to save the brew etc.

Step forward 4 weeks, and the first samples pour well with a good head, but taste like coins in water, and smell like raw liver ! I haven't picked up other signs of yeast infection: no wet-card, no solvent odours or the like. The only metal of any sort in my kit is the basic kettle element in my plastic boiler, and a more recent brew suggests that this isn't damaged and leaching metals into the brews. Has anyone else encountered that combination of off-taste and odour?

Its more associated to kegged beer, where the keg needs to be passivated to restore the composition of the stainless surface eliminating any exposed mild steel. Or the unintentional use of mild steel in your process could be a cause.

 

[robgoch]

Thanks, Foxy: I'd read about passivation, but the lack of metal implements and containers would, I'd have hoped, head off any reactions from metal: the mash/boil was via a plastic Thruxton Electrim boiler, the FV a bog-standard Wilko plastic brew vessel, and all the beer is bottled, mostly in Wilko flip-tops. The only metal of any substance in the kit is the kettle element - I believe it's possible to corrode that via unsuitable sterilisers such as Campden tablets: I usually use BruClens - and I'm convinced it's unpitted and won't be leaching metal.

 

[foxy]

Thanks, Foxy: I'd read about passivation, but the lack of metal implements and containers would, I'd have hoped, head off any reactions from metal: the mash/boil was via a plastic Thruxton Electrim boiler, the FV a bog-standard Wilko plastic brew vessel, and all the beer is bottled, mostly in Wilko flip-tops. The only metal of any substance in the kit is the kettle element - I believe it's possible to corrode that via unsuitable sterilisers such as Campden tablets: I usually use BruClens - and I'm convinced it's unpitted and won't be leaching metal.

For me I would focus on the element, make sure it is stainless steel, a lot of elements are coated nickel which the acid wort will chew through, the mild steel under the nickel will leach into the beer. Buy yourself a new stainless steel element off Aliexpress, it will eliminate the most probable cause.

 

[An Ankoù]

I make a couple of milds on a regular basis and I always mash for a long time, often overnight. I've never had the metallic taste you describe so well that I can almost taste it from your description. But I have had the flavour in beer when I've reused 5 litre party kegs. There, the answer was obvious, they were rusting inside. So in your process, there's no contact with Iron, and extending the mash doesn't leach iron out of the dark malts because there isn't any there to start with! I know Guinness was prescribed for anaemic patients during the dark ages, but that was just a marketing ploy based on myth, "Guinness is good for you". I think there must be something in your recipe that's giving you the flavour. Could you give us full details including a description of your water and any water treatment you use. I might even knock up a small batch to see what happens.

 

[robgoch]

Thanks, An Ankou: I've attached the kit spec. (-it didn't give malt proportions); we're a hard-water area, and, perhaps significantly, I used no treatment: I've since read a couple of comments elsewhere that imply that treatment is crucial for milds, especially light mild. The other comment I'll make - this might be very much a newbie error - is that I didn't obsess about the strike/sparge volume differentials: this is because I contacted the kit supplier (-they also brew), who got back to say that he wasn't that particular where sparging was concerned, and aimed instead to get the accurate pre-boil volume. This area might be a lesson I've got to learn: sparging hadn't seemed to make much difference to the part-grain brews I've done so far, but all-grain might require a much more scientific approach.

 

[robgoch]

For me I would focus on the element, make sure it is stainless steel, a lot of elements are coated nickel which the acid wort will chew through, the mild steel under the nickel will leach into the beer. Buy yourself a new stainless steel element off Aliexpress, it will eliminate the most probable cause.

Foxy: will pick up a spare/replacement as a matter of course, just in case. Thanks..

 

[The Baron]

I would certainly use Campden tablets and change the element if possible for a SS one in a ideal world. Not saying it is absolutely that but they are standard brewing essentials the campden and only SS in contact with the boiling wort

 

[hoppyscotty]

Water treatment might be an element. I do find some commercial beers have a metallic taste....especially St Austell's beer...I actually find it quite pleasant in this case. I did stumble on an interview with James from Verdant and he mentioned it as being a specific characteristic of the mains water in Cornwall and they had decided to work with that rather than try to dial it out with water treatments.

 

[Caramel Ox]

The strike/sparge quantities look very strange so I wouldn’t have followed those anyway. You would have sampled the beer a few times before bottling so I wonder if you are looking too far back for the issue? It has only been a problem post bottling?

 

[robgoch]

The chap at the kit supplier essentially said that RE the balance of volumes ! He said he'd check and change for future versions, but basically implied that he didn't really sparge, and suggested I concentrated on achieving the boil volume listed, which I did. The OG came out at 1042, which I took to be a good sign, and vindication of my ignoring the sparge instructions (folk on here will no doubt upbraid me for being so casual !). So, yes, RE your comment about it manifesting post-bottle: there was nothing off-tasting in the FV - it just wasn't very interesting. I tried the first bottle on 28th February and only the metallic taste was prominent: 2 bottles opened this week both exhibited the 'bloody meat' odour I referred to in my opening post. So things appear to be happening in the bottle. Sadly, I expect that my hope that bottle conditioning would even out odd flavours, etc, to not be achieved!