Why Is 23l The "standard" Single Batch Size

[pint of lager]

TD, it's a very fine ale, passed on to me by Graham Sanders many years ago. Makes a great house ale.

 

[Ash in Perth]

Any one seen the movie 'number 23'

i always thought it was just carried on from US home brewers, 6gal = 22.7L but your right, they seem to work on 5 gal.

 

[SpillsMostOfIt]

An obvious batch size (for some people, at least) is one that accommodates a Cornelius keg.

Nineteen litres. Easy.

After 19, the next largest natural prime number is 23.

The sum of two and three is five, the number of US gallons in 19 litres.

Makes perfect sense.

 

[Kai]

23L is also a good amount to lift comfortably and safely.

 

[Sammus]

British or American pints?

Be careful if you are converting recipes to metric. Often American recipes will not state a volume and expect you to know that it is 5 American gallons or 19 litres. Australians expect it to be 23 litres.

AG brewers often negate this by expressing a recipe in the form of percentages such as
70% Pale ale
20% Munich
10% Wheat
og 1.050
IBU 25 Styrian Goldings
Flavour 1 gm /litre 10 minutes from flameout
Aroma 1 gm/litre 1 minute from flameout

I've always been a little confused with recipes in this format, because the flavour (and aroma to a lesser extent) hops add to the IBU rating, so should it be the bitterness addition brings it to 25 IBUs, then with all the others it may be closer to 30 or 35? Or should it be bittering with styrian, plus the others, should total 25?

 

[Kai]

I always read and write them as the bitterness being the sum of all the hop additions.

 

[alexbrand]

23L is also a good amount to lift comfortably and safely.

But most of the time it's not enough for a real party...

Alex

 

[chovain]

haven't got time to read all the replies but isn't it because that is legally what a homebrewer is allowed to brew each week in australia?

There's no limit on the batch size for home brew, as long as it's not commercial.

 

[Whistlingjack]

I always thought it was because the usual fermenter size was 25 litres and putting 23 litres in there left enough headspace.

WJ

 

[MHB]

Slightly OT but:-
I usually assume that the stated IBU's are the total for the beer. Most recipes give OG-FG, Colour and Bitterness - for the finished beer

If the recipe calls for 25 IBU's from what ever hop you have 2 choices.

Add 25 IBU's with the bittering hop; then ignore the 3-5 IBU's you will get from the late additions.
Or subtract the 3-5 IBU's from the 25 so your total matches the recipe.

Either way as people generally can't discriminate closer than about 5 IBU - not going to make a big difference. But you get to choose.


Back OT
I think the assumption that gear is made for home brewers is generally wrong - we get to use what is out there, long before home brewing was legal; there were lots of 5Gallon containers.
They and their metric equivalents were just adopted by brewers as a matter of convenience.

Same for the Americans they adopted 5 US gallon containers; Cornelius kegs were made for the soft drink industry - we utilise them - it wasnt until the short fat SS kegs came onto the market a year or two ago that we first saw "Purpose Built HAnyway standard plastic fermenters are available from my suppliers in a number of sizes 15 L, 20 L, 22.5 L, 27.5 L 30 L, 60 L and occasionally 120 L, pick your favourite standard size and brew some.

MHB

 

[mfdes]

For me, as I have the old Schweppes Firestone 21L kegs, 23L is a natural batch size. After accounting for losses to trub and yeast, I end up with a full keg and enough liquid in the fermenter to stir up the yeast sediment for bottling to re-use (if I'm using liquid yeast).

I always assumed it was because of both the headspace issue and it being equivalent to 6 US gallons or 5 imperial gallons, which brewers in the US and UK often use.

MFS.

 

[SpillsMostOfIt]

When I first started brewing, I just did whatever the fine people at Coopers (and their ilk) told me. Doesn't count.

I moved to AG brewing at about the same time I got me a fridge for fermenting. Annoyingly, I had to do some research.

I forget which order it all happened in, but a Bunnings 25litre drum fits nicely in the fridge and holds the contents of a Willow 20litre plastic jerry can (with a little left in there for yurk I don't want in the fermenter). This translates to (conveniently) 23 litres meaning I can brew in step with people who package yeast and stuff.

This clearly does nothing to address the original question, but does kinda provide 'me too' support for MHB.

I think as a rule of thumb, if a piece of equipment is stupidly expensive, it is probably designed specifically for home brewing and vice versa.

 

[I like beer]

I always thought it had something to do with government laws, as in larger batches where illegal

 

[randyrob]

haven't got time to read all the replies but isn't it because that is legally what a homebrewer is allowed to brew each week in australia?

There's no limit on the batch size for home brew, as long as it's not commercial.

From Here

Home brewing was legalised in Australia under Prime Minister Gough Whitlams Labor government in 1973 in fact, the home-brew law was one of the very first among a raft of new legislation introduced by the highly reformist regime. Before that, it had been legal to make beer at home but only if it was around 1 per cent alcohol (in other words, gnats bladder weak).

The exact wording of the new law introduced under Whitlam allows home brewers to make 22 litres of beer per week. Of course, thats more than enough for any individual to consume but, really, this is only a guideline and I dont know of anyone who has ever been prosecuted for making more than the allowable volume.

Rob.

 

[enoch]

5 gallons. 4.5l per gallon = 22.5l rounded up to 23.

Don't even need the rounding - 4.54 litres per gallon
http://www.google.com.au/search?num=100&am...allons&meta=
23 litres = 5.05929062 Imperial gallons

 

[ibast]

5 gallons. 4.5l per gallon = 22.5l rounded up to 23.

Yep and all the recipes in older books are set up around this.