Off beer

[steve123]

Hello, I’m new to the forum, I’ve used the site many times for information but only recently joined.

I’m after some advice on a recent beer I’ve done. It has a vinegary taste, just trying to work out where it went wrong.

It was AG mainly pale malt, with some crystal and roasted barley. Fermented in a blue 60 L plastic barrel drum, batch size was 48 litres, was kept in garage in water bath, fermentation was kept about 19 C. Fermented 25 days then bottled. I used Safale 04 yeast but only one packet, OG 1.058, FG 1.016

Tried after about 10 weeks, no vinegary smell to it but has a vinegary taste to it, just after thoughts of where I went wrong, could it of been that I didn’t use enough yeast and the yeast in there was too strained, or just an infection, my sanitation is generally quite good. Thanks

 

[Oneiroi]

Welcome to the forum!

Unfortunately the only thing I know of that causes vinegar flavours is an infection of Aceto bacteria, although other forumites might know of other sources.

One sachet of yeast for 48 litres does sound like a bit of an underpitch, although I'm not sure if this can cause the off flavour by itself, my understanding is that the long lag time while it builds up does leave it slightly more vulnerable to infection.

 

[Mavroz]

Is your 60l blue plastic barrel drum food grade plastic?
If not you may get a taint from the plastic.

 

[steve123]

I think it is, it’s classed as HDPE and advertised as suitable for food stuff, but maybe it is this.
I normally use the standard 5 gallon fermenters and I have never had a problem with them, I have used the blue barrel once before with a 7.5 abc beer with no ill effect

 

[Mavroz]

Ok, I was always told not to use any vessel that isn't clear or white. Not sure how valid that is.
I am sure you will be just fine, just a thought but if you have used them before it can't be that.

 

[rank_frank]

I know of a micro brewery that used some second hand blue barrels for conditioning. It worked fine except that the taste of the previous contents was impossible to get rid of (it was orange juice). So I wonder if, although food safe, there's something about that plastic that stuff gets stuck in and could be an infection source?

 

[Dads_Ale]

You have certainly underpitched with only one sachet of SO4, I would probably have used at least three. It may be that the lag in fermentation has allowed bacteria to take hold. Also it was quite a long time in the FV so plenty of time for nasties to take hold.

 

[Zephyr259]

Vinegar would mean acetic acid which needs acetobacter bacteria and oxygen. Is it specifically vinegar? Vinegar is often quite sharp to smell where lactic acid is less obvious. Both come from bacterial infection but lactic sourness can be pleasant, acetic generally isn't. Did you leave this in the FV for 10 weeks before trying it, or is the 10 weeks including time in the bottle?

 

[NIGHTSKY BREWING]

One packet.... please....sorry....April fools day is a long way off .....sorry.

Any how welcome...there's many Gents on here with many years brewing experience .