What's my infection?

[neilpcraven]

Hi all,
It seems I've got an infection somewhere in my brewing process and I'd like some help to identify it.
No visual clues, so sorry, no pics.

I'm getting an off flavour but no off smell. I can't describe it very well. It's not nasty but it's not super nice. Maybe like old hay, but not as grassy? If it were more mellow it wouldn't be a bad flavour in a beer. The flavour hits you on first sip, and also leaves the mouth very dry, almost like tannin astringency. It's not sour/bitter astringency either. After half a glass of beer or so, it becomes less noticeable - I guess your mouth adjusts to it?

I'm certain it's an infection because I have had this off flavour in two batches of cider (brewed with very different raw ingredients at different times, with mostly different equipment) and now in one batch of beer.

I'm using RO water with nothing weird about the chemistry.
As far as sanitation, I've been generously cleaning with One-step (can't get star-san here) so I have a feeling this is something that is resistant to that sort of 'sanitation'. I guess it's time to switch to bleach until I can get something less smelly.

Since it's affected my cider as well as the beer I guess it's something that lives in abundance in the area where I brew - the FV for the cider was brand new and it's not like it needs to be open for long when you chuck in the cider ingredients, which is unfortunate as it's gonna be an uphill struggle for any brew

 

[calumscott]

Grassy is described here as being attributed to acetaldehyde...

http://www.bjcp.org/docs/OffFlavorFlash.pdf

 

[pittsy]

Are you adding anything to the water as RO needs adjusting for brewing .

 

[neilpcraven]

Are you adding anything to the water as RO needs adjusting for brewing .

I did for the beer but not the cider. Used Beersmith to calculate. Some Gypsum and some table salt if I remember rightly.

 

[neilpcraven]

Grassy is described here as being attributed to acetaldehyde...

http://www.bjcp.org/docs/OffFlavorFlash.pdf

Yeah - I don't notice any sort of acetic/cidery flavours. Tt's more farmyard than cut grass.

 

[neilpcraven]

Well, I've just discovered that sour cream pringles mask whatever the off-flavour is so I guess I'll just need to keep a stock of them for whenever I open one of these brews :P

 

[Jeltz]

Sounds like Brett to me

 

[neilpcraven]

So I took it to my BJCP qualified friend. I'm relived to know it's metallic - probably from cleaning my chiller too well before using it.

So relieved it wasn't infection! But, it doesn't really save the batch