TOPIC:

Hi all-

I have been thinking, since yesterday, about something I heard a couple of times over the past few months (Once on this forum, from a poster in the context of a thread about pricing, and once in person from a brewery employee at the RDS craft beerfest).

The suggestion was that although a particular ABV might be listed on a bottle or in respect of a particular keg of beer, in actual fact the reality could be different.

In the RDS case, it was suggested to me that the keg that was tapped at the RDS was from a batch that in fact had a higher ABV than was ordinarily listed by the brewer for that beer.

Now, before getting into whether or not this is a good or bad thing, I was curious whether this is actually the case. Could anyone with a bit more brewing knowledge shed a little light? Is there any noticeable deviation in ABV from batch to batch - different bottlings, kegs, casks etc. ?

Batches can and do vary in ABV. Even the most exacting brewer will have variations from batch to batch.

Materials are a large variable. Mated barley, even from the same maltster, can have slight variations in starch content and/or enzymes, leading to variations in wort strength.

Variations in mash temperature can cause one wort to be more fermentable than another, meaning a variation in final gravity, hence alcohol content.

Fermentation temperature and yeast viability can be a factor too, but that is unlikely in a well run brewery.

The large mega-brewers blend batches and add sterile water to achieve absolute consistency from keg to keg, but it is a rare mico that is set up for that.

As far as trading standards goes; the beer can be 0.2%ABV either side of the stated ABV, so a beer that is down as 4.3%ABV may be as low as 4.1%ABV or as high as 4.5%ABV.

Whether microbreweries stray outside that, I do not know, but I strongly suspect that the macro brewers, with their ability to achieve precisely the ABV they are looking for, are consistently 0.2%ABV below the stated amount. I have no evidence to back up this suspicion, but it seems like a no brainer from a business standpoint. If you have a beer at 4.3% and you can legally water it down to 4.1%, while telling people it's 4.3%, then you get to sell more beer for the same outlay.

Well AB-InBev were accused of watering down their beer in the US so you're right that it's definitely something a business would get up to.

I'd say micro beer does fluctuate but I'd personally be more concerned with how it tastes each time rather than the alcohol content.

"irish_goat":2tl9qsn7 wrote: I'd say micro beer does fluctuate but I'd personally be more concerned with how it tastes each time rather than the alcohol content.[/quote:2tl9qsn7]

+1 on that. As long as it's somewhere in the ball park when it comes to ABV.

There can also be a gap between label and contents when there are legal thresholds involved.

Spoke with a Canadian beer geek who said that 11% is the point at which a beer magically becomes a wine in Canada and is subject to different tax and transportation rules; therefore several big Canadian craft beers are tagged as 10.8% though results may vary.

Haven't heard of the same for the tax break at 2.8% in the UK, but I wouldn't be surprised.

The label is not what concerns revenue in Ireland. They charge alcohol duty on the actual ABV of the beer, according to your brewery records (with occasional lab testing to verify your ABV declarations are correct), not what's on the label. What you tell the public is one thing and can be fudged a little, what you tell the tax man is another matter entirely.