Water Levels

simonb · Post by **simonb** » Tuesday Apr 26, 2005 2:45 pm

When brewing kit beers - how much water do you put into the fermenter?

I used to do the standard 23ltrs, but recently have dropped it down to 21ltrs - I find that it ferments better (quicker) and the beer has a better texture

Do most people go the standard 23ltrs?

Do I get more alcohol from dropping the water level?

cheers
simonb

Hillbilly · Post by **Hillbilly** » Tuesday Apr 26, 2005 3:16 pm

That depends on what kit your brewing, each brand or kit requires more or less water but a liter or two less does improve the taste and body.

Jay · Post by **Jay** » Tuesday Apr 26, 2005 3:20 pm

I too have started brewing at 21-22 litres rather than the 23 and have found I get better beer (regardless of style - well 18L for stouts).

Cheers,
Jay.

Evo · Post by **Evo** » Tuesday Apr 26, 2005 5:58 pm

Yeah, I do a bit over 18 litres as that's what fits in my kegs. A bit over to allow for the sediment in the bottom of my fermenters x 2 (racking). I think it's the general concensus that dropping the volume will give you a better beer.

Jay · Post by **Jay** » Tuesday Apr 26, 2005 6:11 pm

What's 5 American Gallons...19L? Alot of American recipes quote 5 gallons and have about the same amount of fermentables that we put in 23L. This made me start making my brews to roughly 21L (half way

.

Actually I think I may have ruined a stout on the weekend by accidently filling to 21L while on auto pilot

Should be right as the predicted OG was 1.066 for 18L and mine was 1.062 at 21L so fingers crossed.

Cheers,
Jay.

gregb · Post by **gregb** » Tuesday Apr 26, 2005 7:01 pm

Relax Jay, you'll probably get away with it.

Greg.

Tay · Post by **Tay** » Tuesday Apr 26, 2005 8:55 pm

Hi, I'm a newbie here. I just started my first batch ever and wouldn't you know it I went on auto-pilot and put too much water in. 5 litres extra! I was tempted to abort but a mate reckoned if I add some extra sugar it may taste a little weak but still have decent alcohol content.

The fermentor has been bubbling away for the first 3 days so there's definitely some activity.

Does anyone have any thoughts on what I might end up with?

Thanks in advance. This is a great site!

Tay

Post by **Oliver** » Thursday May 05, 2005 11:57 am

Simonb,

Yep, if you reduce the quantity of water you'll increase the amount of alcohol (by about 8.6% over what it would have been).

Tay,

I reckon your mate is right. Even though the beer will be a little on the thin side, adding some extra sugar will boost the alcohol content to a reasonable level. Try adding malt instead of sugar, as this will help the body, too, rather than just adding alcohol, making it less "watery". Perhaps 500g would be a good amount. Dissolve in boiling water, cool and add to the fermenter.

Cheers,

Oliver

Bob the Brewer · Thursday May 05, 2005 12:55 pm

Oliver,

Does it increase the alcohol by 8.6% or was that meant to be 0.6%

This is a sensational site mate

well done to you and your members for such excellent discussions on such a noble pursuit!

Post by **Oliver** » Thursday May 05, 2005 2:27 pm

Bob,

Thanks for the kind words.

It's 8.6% (not 8.6 points) above what it would otherwise have been.

Here's the maths:

23 litres - 21 litres = 2 litres
2 litres / 23 litres * 100 = 8.6
So 21 litres is 8.6% less than 21 litres.

Putting that to use, say at a volume of 23 litres you got a beer than was 5.0% alcohol. By reducing the volume to 21 litres you're adding 8.6% to the original 5.0%, resulting in a beer that's 5.43% alcohol.

Maths:

5.0% * 1.086 (This is the same as multiplying by .086 and adding the original figure) = 5.43%

But maths was never one of my strong points.

Someone tell me I'm right.

Oliver

Guest · Post by **Guest** » Thursday May 05, 2005 2:31 pm

Sorry Oliver I see maths and switch off

You're on your own.

Jay.

peterd · Post by **peterd** » Thursday May 05, 2005 3:38 pm

Actually, I think Oliver switched off when maths was happening as well

But it turns out the errors involved with his calcs are relatively insignificant, and the figure comes out to be (according to my calcs, and assuming alc production (i.e. attenuation) is unchanged in the smaller volume, a risky assumption) is approx 5.4762% for his example.
Sorry to seem so nitpicking, but I always wanted to find a use for a fairly expensive education, spread across several decades and continents

peterd

Bob the Brewer · Post by **Bob the Brewer** » Thursday May 05, 2005 4:43 pm

Well done lads!

The guy at my homebrew shop said that the rule of thumb was a 0.5% increase in alcohol level for every litre of water reduced. So unless the unchanged attenuation assumption peterd mentioned is in fact invalid, it would seem that my HBS rule of thumb greatly over stated the change in alcohol %.

I think the actual result may lie somewhere in between the two schools of thought. HBS says 2 litres reduction leads to 1% higher alcohol; Oliver's calculations indicate about a 0.5% increase.

Regardless of any of that, reducing the water definitely leads to a fuller flavoured beer and that's what its all really about

Cheers,
the brewer

p.s. I'll admitt that i did miss read Olivers message

gregb · Post by **gregb** » Thursday May 05, 2005 8:57 pm

What ever happend to guessing and or making it all up as you go along?

Greg

Dogger Dan · Post by **Dogger Dan** » Thursday May 05, 2005 9:05 pm

Greg

Thats what they are doing,

It is just a very good guess, the better the guess the better the beer

I love it when Science and Art can come together

Dogger

JAZZA · Post by **JAZZA** » Thursday May 05, 2005 10:04 pm

hey oliver,
I think pythagoras's therom my have worked better

just jokes

good job we aren't so serious at this web site

lifes just tooo short, so drink home brew and enjoy it

gregb · Post by **gregb** » Friday May 06, 2005 7:09 am

Is brewing a science or an art?

I prefer it to be an art, because art just leaves me so much more room for me to bullsh*t myself sillly.

Greg

Dogger Dan · Post by **Dogger Dan** » Friday May 06, 2005 10:31 am

I am thinking it all depends on your state of mind as to what relm it belongs to

Dogger

peterd · Post by **peterd** » Friday May 06, 2005 11:52 am

Bob,
the HBS guy overstates the increase by a factor of about 2. That is, the increase is 0.5% (absolute, not relative) increase for a two litre decrease in water. Any effect of the attenuation issue would be to make his figures even less correct.
Of course, the effect on alcohol level of reducing water is not linear (because the measure is % by volume), but for the sort of figures we are dealing with, a 0.5% increase (decrease) for every 2 litre decrease (increase) in water level is a reasonable hueristic.

and yes, I acknowledge that I am a pedant, but higher degrees in maths and computer science seem to do that to a guy every time

peterd

Jay · Post by **Jay** » Friday May 06, 2005 12:51 pm

If you wanna work it out plug different volumes of water into this (http://www.brewcraft.com.au/wa.asp?idWe ... etails=120) brew calculator along with the rest of your recipe and see what happens. Maths is all done for yah.

Cheers,
Jay.