Coopers' formula for determining alcoholic strength?

[ex0ja]

Hey, I'm just a little confused about what the formula for determining alcoholic strength is meant to be. In the manual that comes with the Coopers Micro-brew kit it says on page 11 that the formula is "[(1040-1006)/7.46] + 0.2". However, in the little instrctuctions that come with the beer concentrate cans it says the formula is [(1040-1006)/7.46] + 0.5.

The manual says the addition of 0.2 is to account for the priming sugars. Does the type of priming sugar used effect the alcoholic strength? Perhaps that's why these are different.

Can anyone explain why these two Coopers forumulas are different?

What is the formula meant to be?


Also, while I'm on the topic of the Coopers micro-brew kit manual there is also something else confusing. On page 9, under '4. Enjoy', it says "Storing (conditioning) your beer beyond two weeks and up to at least three months should see the flavour improve, the bubbles reduce in size and the yeast deposit becomes more compacts."

The part where it says "Up to at least three months" seems contradictory and makes little sence to me. It is either "up to three months" or "at least three months", which is it?

Thanks.

[gregb]

Ex,

The 0.5 or 0.2 is to account for the priming sugar. It was in the Coopers club newsletter a while ago that they revised thier formula after checking some experimental batches.

I split the difference and use 0.3.

Cheers,
Greg

[gregb]

Dunno about the storage thing, my own experimentation indicates that most batches will improve most noticibly in the first 3 months, but can be stored in some cases for more than 2 years. Some other batches staled after 12 months however.

CHeers,
Greg

[Rubber.Piggy]

The part where it says "Up to at least three months" seems contradictory and makes little sence to me. It is either "up to three months" or "at least three months", which is it?

I think what they are trying to get at is that is will improve for at least 3 months, but may keep getting better or may not. This is a commercial product so they are probably just covering themselves by saying "up to".

Sort of like saying you can store up to "this long", but the definition of "this long" might be longer than that. I agree that the phrase is badly written.

EDIT: wrong word, no sense make

[Auscol]

I split the difference and use 0.3.

Cheers,
Greg

Same here

[chris.]

0.3 here too.

Ex, there is no simple formula to use (along with a hydrometer alone) to accurately determine alcohol content as alcohol has a lower SG than water.

[Hashie]

I'm not overly fussed in getting 'acurate' alcohol measurements.
I use the hydrometer to get an idea ie 4 1/2 % alc or 6.8% etc.

All I know is all my beer makes my legs wobbly after having several.

If people ask, I just say it is around 5%, the same as commercial beer. That way they know they shouldn't be driving afterward.

[General]

Remember that you may not be priming if your kegging, so don't add anything to the OG-FG/7.46, but when I bottle I add 0.5, I've seen 0.5 on a few sites so trust it, but may just experiment with fGs after bottle conditioning for a few weeks.

I'll get back to you (bottling on Sat).

[Oliver]

... The part where it says "Up to at least three months" seems contradictory and makes little sence to me. It is either "up to three months" or "at least three months", which is it?

This is just really bad use of English on the part of the person who wrote it (and those who checked and approved it).

I'm afraid to say that this is not unusual for Coopers: Just have a read of their website, newsletter or instructions that come with their homebrew microbreweries. Sorry to anyone from Coopers who might be reading this, but sometimes it seems that whoever writes this stuff has English as their second language and has no idea about possessive apostrophes, singlulars and plurals and the use of commas, to list but a few common mistakes in their literature.

But to cease the rant and answer your question, they do, I suspect, mean "up to three months".

Cheers,

Oliver

[kurtz]

Ex, there is no simple formula to use (along with a hydrometer alone) to accurately determine alcohol content as alcohol has a lower SG than water.

Depends what % you are talking about.
I am BTW discussing the normal range of beer strength here and your results will be closer than your hydrometer resolution.

ABV is simple
ABV = (OpeningGravity - Finishing Gravity)/0.75
thus a beer starting at 1040 and finishing at 1012 (assuming no further fermentation) will be 3.75% ABV
ABW (which do not tend to use but others do) must take into acount the alcohol produced and as ethanol has an SG of 0.79 we use this formula
ABW = (ABV*0.79)/Finishing Gravity.

Does this help..well as you brew and discuss more and more you will find yourself saying things like "this had to ahve been a 1060"

K

[morgs]

hey all,

I noticed this same instruction and was also confused. I just assumed i could drink my beers after two weeks. However after looking on this forum and after trying the first couple of batches i've brewed up. My decision is to hold out until at least the three months

[Chris]

I'm with Oliver. The Cooper's manual is hopeless.

They are trying to split the difference between new brewers (making it sound as simple, quick and cheap as possible); and more experienced brewers.

The Cooper's instructions are fine to start brewing with, but once you are in to it a bit, start reading up on brewing a bit. And don't use Cooper's brewing sugars or "brew enhancers" just because they say so.