off flavours

[heeler58]

Hi, one of my beers has off tastes of melting plastic and a sourish cidery flavour!😕 Any ideas please.☺

[johnrm]

Is that a bottle or a can of Heineken?

Please enlighten with recipe, equipment and process.

[heeler58]

Firstly, thanks for replying and secondly, it's not a doomsday situation so no Heineken here!😂
It's a blonde beer, simple as you like and the same as others that I've made. It's the first out of 25 all grain brews that I've done that tastes off with a mild sour taste like an underlying tangy plastic taste. Its only happened to me in total 3 times in all my brewing career of 30 odd years. Maybe it's a lapse of cleanliness or a beer fly got in?

[auralabuse]

Firstly, thanks for replying and secondly, it's not a doomsday situation so no Heineken here!😂
It's a blonde beer, simple as you like and the same as others that I've made. It's the first out of 25 all grain brews that I've done that tastes off with a mild sour taste like an underlying tangy plastic taste. Its only happened to me in total 3 times in all my brewing career of 30 odd years. Maybe it's a lapse of cleanliness or a beer fly got in?

Could your water pH have gone up for any reason?

[heeler58]

No, it's excellent water from the same source.

[johnrm]

So, allgrain and blonde.
No mention process or equipment, ingredients, yeast.
What do you sanitise with?
I suggest a deep clean on all cold-side equipment.
Light bleach solution, followed by boiling water or steam, followed by Starsan.

[heeler58]

I guess the deep clean is the thing, hard work up ahead! Thanks everyone☺

[johnrm]

No steam or boiling on Autosyphons and bottling sticks - These tend to deform

[beerfly]

plastic like taste = chlorophenols; can be caused by high levels of chlorine in the water or not properly rinsing off chlorine based cleaners
sour like taste = most likely caused by wild yeast or bacteria

if most of your brews are fine then you can rule out the water. depending what you use to clean it might not have been washed of properly or something did get in.

[johnrm]

If chlorinated water is a concern, you could add a charcoal water filter.
No affiliation, but I found these guys...
http://www.waterfilterireland.com
I was given an under counter, just need the filters.

[Ohnidog]

If the beer had chorophenol it would be much more intense then you're describing, the smell alone would put you off tasting it! Its a very flavour active compound so even a small amount will dominate

It could be down to a wild yeast which produces a styrene flavour, it could be a sulphur or yeast bite

At what stage is the beer? Are you tasting this from the fermenter or draft/bottle? Is it hazy?