Kit Beer Specs

[barls]

ok guys there was a thread where there was a excel file that had the ibu's and srm's of kits commercially but i cant find it. here is an updated version now including the country brewer range
View attachment 21035

 

[buttersd70]

Barls,
Good chart, however in relation to kits whose IBU rating is given as a concentrated value, and refering specifically to coopers....

Your calculations are absolutely correct for working a concentrated IBU back to a diluted value for a 23L batch, however I don't think Coopers deals in such niceties....I can't comment on the other manufacturers who give a rating in a concentrated formula, but have done quite a few coopers kits and find that the results are quite different than the numbers.

Taking the Mex Cerveza as an example, with IBU of 300, this should give 16.3 IBU in 23L. This would mean that any amount of malt added up to an OG of 1032 sould give a BUGU > 50%. ie any amount of malt up to 600g. Can you imagine 600g of ldm added to this kit without it being ridiculously sweet? I sure cant.....Having added 250g ldm (plus dex etc, which does not contribute to residual sweetness), and also having done this kit with reduced volume and 250g ldm with nothing else at (if I remember rightly) 16L, my conclusion is that the actual IBU in the kit is not a correct dilution formula, but a straight IBU/vol. ie 300/23=13IBU, as both samples had the same relative bitterness in a side by side. (which was also done blind). The calculations for this bear out the theory that coopers use a straight division as opposed to correctly stating the concentration. Similar results can be found with the Coopers Draught tin. At 420 IBU, corerectly worked out to 22.8IBU in 23L, this means that the addition of 1kg ldm in 23L would give og 1039 and BUGU of 58.5%.....and anyone that has ever added even close to this much malt without additional hopping knows that its nowhere near 58.5% BUGU.

As I said, I think your calculations are absolutely correct, at least the way it should be. But I think the Coopers information is pretty dodgy.

 

[Jamz]

Barls,
Good chart, however in relation to kits whose IBU rating is given as a concentrated value, and refering specifically to coopers....

Your calculations are absolutely correct for working a concentrated IBU back to a diluted value for a 23L batch, however I don't think Coopers deals in such niceties....I can't comment on the other manufacturers who give a rating in a concentrated formula, but have done quite a few coopers kits and find that the results are quite different than the numbers.

Taking the Mex Cerveza as an example, with IBU of 300, this should give 16.3 IBU in 23L. This would mean that any amount of malt added up to an OG of 1032 sould give a BUGU > 50%. ie any amount of malt up to 600g. Can you imagine 600g of ldm added to this kit without it being ridiculously sweet? I sure cant.....Having added 250g ldm (plus dex etc, which does not contribute to residual sweetness), and also having done this kit with reduced volume and 250g ldm with nothing else at (if I remember rightly) 16L, my conclusion is that the actual IBU in the kit is not a correct dilution formula, but a straight IBU/vol. ie 300/23=13IBU, as both samples had the same relative bitterness in a side by side. (which was also done blind). The calculations for this bear out the theory that coopers use a straight division as opposed to correctly stating the concentration. Similar results can be found with the Coopers Draught tin. At 420 IBU, corerectly worked out to 22.8IBU in 23L, this means that the addition of 1kg ldm in 23L would give og 1039 and BUGU of 58.5%.....and anyone that has ever added even close to this much malt without additional hopping knows that its nowhere near 58.5% BUGU.

As I said, I think your calculations are absolutely correct, at least the way it should be. But I think the Coopers information is pretty dodgy.

Coopers actually say in their FAQ how they expect everyone to use the data that they give for their kits...

To calculate the bitterness of the brew: multiply the quoted product bitterness by the weight of the product (1.7kg)* and divide by the total brew volume (normally 23 litres).
* We use the weight because our quoted colour/bitterness figures are base on a weight/volume dilution.

Product Bitterness x 1.7 / Brew Volume = Total Bitterness before fermentation

As an example, if a brew is made with Mexican Cerveza up to a volume of 23 litres:

270 x 1.7 / 23 = 20 IBU (International Bitterness Units)
This figure represents the brew bitterness prior to fermentation. Generally, fermentation reduces colour and bitterness by between 10 to 30%. So final bitterness of the fermented brew may be anything from 14 to 18 IBU.

Colour may be calculated in the same way. Ensure to add the colour contribution of all ingredients together. Colour figures are quoted for liquid extract are at the time of packaging as these products will darken with time. The darkening process is accelerated by exposure to elevated temperature.

 

[barls]

ok i cant claim the responsibility for the coopers data, i only got the country brewer section of it.

 

[buttersd70]

Coopers actually say in their FAQ how they expect everyone to use the data that they give for their kits...

I was unaware that they had this in their faq, thanks Jamz....but what a wierd way of doing it :huh: That means the cerveza is supposedly 22.17IBU - even more than with the straight division!

1x mex cerveza tin and a kilo of malt anyone? Just keep the insulin handy in case.

Barls, I know you're not responsible for coopers data, I hope I didn't come over as having a go, cos I wasn't. You can only go off the information that is publically available, after all. Having read the faq data posted by Jamz, it seems to me that coopers is on another planet, maybe? strange, strange stuff.....

 

[barls]

it didnt come across that way mate, i just couldnt find the original thread on it.

 

[Adamt]

Butters: I'm pretty sure the IBUs quoted (and colour) will be very close to the actual levels encountered in the kits. The brews that go into the kits are made on the same equipment as the commercial products and are subject to similar quality control.

The cerveza, draught, lager kits are not meant to be made with 1kg+ of actual malt, so the BU:GU ratios may seem out of whack but with simple sugar additions you shouldn't get the same sweetness through.

IBU is roughly a measure of concentration of isomerised alpha acids. So the proper formula should be: IBU = product ibu / 1.25 * Final Volume, as the volume of the cans is 1.25L.

 

[Macca17]

Was going to do a two can with the Mex Cerveza and add 1kg of LDME and some dry enzymes, if what you say is correct
then this would be too sweet, may just leave out the LDME I think, or use some Dextrose instead.

 

[buttersd70]

Butters: I'm pretty sure the IBUs quoted (and colour) will be very close to the actual levels encountered in the kits. The brews that go into the kits are made on the same equipment as the commercial products and are subject to similar quality control.

The cerveza, draught, lager kits are not meant to be made with 1kg+ of actual malt, so the BU:GU ratios may seem out of whack but with simple sugar additions you shouldn't get the same sweetness through.

IBU is roughly a measure of concentration of isomerised alpha acids. So the proper formula should be: IBU = product ibu / 1.25 * Final Volume, as the volume of the cans is 1.25L.

Adam, I think you've hit the nail on the head here, that when dealing with simple sugars, you don't get the same residual sweetness through. But when dealing with BUGU, only the malt component should be used in the calculation anyway due to the reletive fermentability differences between malt and other sugar types. And yes, the proper formula is as you stated, that is the same formula that barls has used in the spreadsheet. (and obviously, from jamz's post, is not what coopers actually use, hence my stupefied headscratching). I think that the ratings that coopers use, in particular, are more indicitive relevant to the adjunct suggestion for the particular kit, as opposed to a strictly correct formulation of what the actual IBU is. So in the case of cerveza with BE2 (ie 250g ldm), 22 IBU -10% ie20IBU (calculated the coopers way) in 1040 gives 50%BUGU, which makes absolute sense for what this kit with BE2 would give perceptually. It's not really 22IBU in 1040, though....if you discard the fermentables that leave no residual sweetness and therefore don't contribute to the sweetness, its actually more like 13IBU (ie IBU/vol) in 1026, ie 50%BUGU, with the rest of the grav made up with dex and matodex, which don't contribute to sweetness post-ferment.

I know that (product IBU/vol) is not correct. All I am saying is, that with the IBU ratings as advertised by coopers, it gives, in practice, at 23L, a closer indication of the relative bitterness of the kit, when made with all malt, or malt in excess of whatever is in the adjunct pack that is reccomended for it.

One of the reasons why I don't use kits anymore