IBU help

[breadnbutter]

G'day readers,

Ok, I'm struggling to come to terms with this IBU stuff. I've explored several links and read Palmer's info. Basically I'm trying to find out how best to work out the amount (metric) of hops to add to a high gravity wort boil (and how best to estimate this as it never occurred to me to take hydrometer readings of a concentrated wort boil ) so that I end up at a reasonable IBU# for the style of beer once final volume is made up.

I'm sure I'll eventually figure out that the best way is to enter the full Tinseth equation into a spreadsheet but if someone could shortcut my quest I'd be most grateful.

Cheers

[Chris]

Convert the IBUs into MBUs and go from there. I don't have the formula on me at the moment- can anyone help out?

[chris.]

Sorry can't help with the MBU's. I suggest getting yourself brewing software like promash, beersmith, or beertools.

If I was to do it by paper I'd just work it out using the BU/GU ratio's. It's probably not 100% accurate but should get you close.

Firstly figure out the SG of your boil by using a calculator like this & subbing your boil volume with the "total volume in fermentor":

http://www.brewcraft.com.au/wa.asp?idWe ... etails=120

Take the final OG & IBU your aiming for (after topping up to 20L or whatever volume your aiming for) & divide the IBU by the last 2 digits of your OG (when working below 1.100 that is). Lets just say you want a beer with an OG of 1040 & an IBU of 32.

32/40 = 0.8.

Then take the last 2 digits of the SG of your boil & multiply that by the above result. Say your boil gravity is 1.080 - 80*0.8 = 64. The IBU you should be aiming for in your boil should be 64.

Now take your boil volume, boil gravity, required IBU, hop AA% & plug them into this calculator to give you the quantity of hops required:

http://grainandgrape.com.au/Calculators/hop_calc.htm

ie. to make 20L of beer at 1.040 with an IBU of 32 with a 10L boil (using 2kg of DME) you will require a boil IBU of 64 using 49g of 5%AA hops.
...I think I don't have a copy of promash to check it out on at the moment.

[rwh]

Sorry can't help with the MBU's. I suggest getting yourself brewing software like promash, beersmith, or beertools.

Or qbrew, which is free software.

[chris.]

Sorry can't help with the MBU's. I suggest getting yourself brewing software like promash, beersmith, or beertools.

Or qbrew, which is free software.

Even better rwh
I havent used qbrew myself. But looking at the screenshots I'm unsure of whether it works concentrated boils?

By the way BnB the method I use above will only work if your topping up post boil with just water (ie. not adding extra fermentables)

[breadnbutter]

Cool,

Thanks Chris, rwh.

I've tried q-tools and from what I reckon it doesn't factor concentrated boils. Still reading but more enlightened, ta.

Cheers

[Ed]

breadnbutter, I have all that in an Excel spreadsheet. Where in Perth are you? You're welcome to a copy, but the workings need a bit of explanation. The other thing you could do is use the chart that Palmer has. Or if you like, I can try to extract the formula and post it. Just a bit complicated because I have it linked to ingredients used, boil volume, efficiency figures, etc.

Cheers, Ed

[chris.]

breadnbutter, I have all that in an Excel spreadsheet. Where in Perth are you? You're welcome to a copy, but the workings need a bit of explanation. The other thing you could do is use the chart that Palmer has. Or if you like, I can try to extract the formula and post it. Just a bit complicated because I have it linked to ingredients used, boil volume, efficiency figures, etc.

Cheers, Ed

Ed, if you could post the formula, or pm me a copy of the spreadsheet it'd be greatly appreciated. I've been messing around in promash & the figures I punted on earlier don't seem to match up with what I assumed they would.
I'm toying with the idea of making myself some 15L wort kits using the no-chill method & am interested in the formula's for caluculating IBU's in relation to dilution rates.
Cheers

[Ed]

chris I can't PM you, that facility isn't available. I have just now allowed emails to be sent to me, so send a message with your email address in it, and I'll send on the spreadsheet. Sorry, but the formula is a little complex and would take me a while to actually put down in any sense. I can explain how to use the spreadsheet in the email (or at least try to).

From memory, all I did was use the formula provided by Palmer and then apply a conversion to take it to metric and also allow for a decrease percentange.

Cheers, Ed