I did some reverse engineering of Coopers recipes based on a photograph of a whyteboard at the old brewery. Here's the post I made to OzCBD:
After a post a while back about the 'Black and Amber' book which contained a photo of a whiteboard listing ingredients for Coopers beers and extracts, I did some hunting around to try to work out how to clone Coopers' beers. Not a big fan, though I don't mind it when I'm down that way - just a nosy *******
I found references to an article by Dr Tim Cooper, in which he said:
"The fermenation is now in cylindroconical vessels, after which the brew is clarified. A controlled portion of the fermenting beer that has not been clarified is added, along with sugar, prior to bottling or kegging, to promote the secondary fermenation."
This would seem to imply that there is no 'bottling strain' - they just add unclarified wort from the primary. It's possible that they add a bottling strain too, I guess, but it seems strange that the article (which seemed pretty detailed) didn't mention it. In any case, there's at least some of the primary strain in the bottle. However, the article goes on to say:
"The Ale yeast is particularly unusual being a mixture of two yeast types which must be maintained in a fine balance. This is necessary because the yeast does not focculate (clump together and settle on the bottom). It remains in suspension and is thus called powdery."
Some more 'reverse-engineering' research:
That whiteboard picture Sean referred to a while back is very interesting indeed. Not only does it give grain quantities for a lot of the Coopers beers, it also gives the ingredients for their extracts and kits. Here's the chart (dated 20.11.2000) (apologies for the dodgy formatting - figures are for pale, crystal, wheat and black malt, eg 4000.500.400.0 means 4000 of pale, 500 of crystal, 400 of wheat and no black):
EXTRACT BREWS
Pale Crystal Wheat Black
Malt N/O 6400.0.0.0
Lager 6400.0.0.0
Pilsener 5400.0.0.0
Draught 6400.100.0.0
Stout 5200.0.440*.880
Dark malt 5600.0.0.800
Ale 6000.240.160.40
Bitter 5000.400.320.120
Classic 5000.260.320.240
IPA 5700.280.320.40
Nut Brown 5000.280.320.240
Crystal 3200.3200.0.0
Amber 6300.240.0.60
Extra light 2900 BARLEY 4000
Light amber 6100.260.0.0
* This figure appears to have been erased, but is still faintly visible.
"LAGER CELLAR BREWS"
Pale Crystal Wheat Black
Birell 5500.160.0.0
DB 5100.80.0.0
Export 6200.240.0.0
Pale Ale 4600.40.200
Premium 5500.Medium 60.280.0
Dark Ale 4650.0.200.200
Ale 5900.40.240.0
Stout 5000.0.440.600
Vintage 6200.Medium 60.350.0
Several of the quantities have an equivalent number of 'bags' written under them. For example, the amount of wheat malt for the Premium is written '280 7 bags'. The bags all seem to be 40kg, although some of the recipes seem to use a 'near enough' approach (eg, the wheat malt for the Vintage is only 350kg, but has '9 bags' written under it, which is 360kg).
Some of the recipes seem to have been 'fiddled with' at some time in the past. The amount of crystal in the Ale recipe seems to have been changed from a number starting with '2' to the present value of 40. The figure for wheat malt in the stout extract recipe looks like somebody tried to erase it but didn't quite get rid of it completely (damn permanent markers) with the black malt figure altered. The Vintage recipe looks like it had only been added recently. Not sure hat the 'barley' is for the extra light extract recipe - any ideas?
A couple of the other recipes specifically state 'medium' for the crystal malt, so I guess the other recipes would use light. (Note - Brad McMahon later advised that the 'medium' malt was MAC Medium, a light chocolate malt.)
A brew at the new Regency Park brewery averages about 10 t / 800 HL, but the picture of the whiteboard was taken when the brewery was still at Leabrook and had a much lower capacity. Most of the recipes on the board seem to run around 6 t, so you could go on a brew length of about 460 HL. This figure would jibe with the move to Regency Park increasing capacity by about 60%.
So if we know the brew length, grain bill and ABV, we should be able to suss out the amount of cane sugar to add. If we scale the the Pale Ale grain bill down by a factor of 1000 and plug it into beertools (46 litres - hmmm, exactly twice a Coopers kit :>, 100% efficiency, 77.5% attenuation) we get a beer of OG/FG/ABV 1.033/1.007/3.34%. Bung in 1kg of cane sugar and you're up to 1.042/1.009/4.3% - pretty close. This would also mean that the kits require you to use exactly twice as much cane sugar as the 'real deal'.
However, this doesn't gel with an article by Dr Tim Cooper quoted on HBD, in which he gives an FG of 1.1 to 1.3 oPlato (1.004 - 1.005). That 'famous octegenarian yeast' must be a mega-attenuator. If we up the attenuation rate to 81%, we get an FG of 1.007 and an ABV of 4.48% - closer again. On the other hand, the yeast might not be as attenuative after all, and it's just the the 4-6 weeks of bottle conditioning that drop it those extra few points.
Cheers!
...Matt...
