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Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 6:00 pm
by Cookie
G'day,

I'm on my 2nd Coopers GB brew and I've added 1.5 kilos of white sugar each time. Both times when I initially tested the Specific Gravity I got a reading of 1012. The brew has clearly been bubbling and fermenting both times (currently into 2nd half of 2nd week), and the SG has only dropped ~4.

What's going on? Is my brew alchoholic or not? Why am I getting such low readings initially?

Answers to any of the above questions would be much appreciated.

Cheers.

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 6:03 pm
by Kevnlis
Did you add the yeast nutrient? Yeast is not able to survive on sugar alone.

1.012 is a very low original gravity for 1.5 kilos of sugar (unless you are making a 50L wort) are you sure you are doing it all properly?

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 6:05 pm
by Cookie
Making a 23lt brew. What yeast nutrient? The pack only comes with the one yeast sachet.

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 6:23 pm
by Kevnlis
Ok, I have only done one Coopers GB and that was ages ago. Maybe they add it at the brewery?

You have obviously done something wrong, just not sure what, can you explain your process please?

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 6:29 pm
by Cookie
Poured 2lts of boiling water into carboy, added 1.5kilos of sugar.

Whilst stirring, added tin concentrate.

Added water to filll up to 23lts.

Checked that temp was between 21 - 28C.

Added yeast sachet and lgihtly stirred.

Took specific gravity reading - 1012.

That was the current brew.

Last time, I dissolved the sugar and concentrate in a pot of boiling water on the stove before adding to the carboy.

Both times gave an initial SG of ~1012.

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 7:04 pm
by Kevnlis
Have you taken gravity readings before? Have you calibrated your hydrometer to be sure it is not off? It just is not possible for 1.5 kilos of sugar (not to mention the GB kit) to be 1.012 in 23L.

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 7:41 pm
by Cookie
I've done three beer brews prior and always achieved initial SG readings around 1040.
I am using the same Hydrometer but maybe it's gone off.
How do I calibrate it to check?

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 8:04 pm
by Kevnlis
Most can be calibrated in 20C tap water, if it reads zero (or close enough to) your alright.

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 8:12 pm
by Cookie
Thank you very much. I have been very concerned about these brews.

If the hydrometer turns out to be alright, any other suggestions as to these abnormal readings?

Re: Weird SG Reading on Coopers GB

PostPosted: Thursday Feb 28, 2008 9:45 pm
by KEG
you've mixed your hot water, sugar and the can of goo, but have you mixed the cold water in as you fill? i reckon all the heavy sugar etc is staying at the bottom. mix thoroughly (can't be too thorough), take SG sample, then sprinkle yeast on top.

Re: Weird SG Reading on Coopers GB

PostPosted: Friday Feb 29, 2008 6:48 am
by warra48
KEG wrote:you've mixed your hot water, sugar and the can of goo, but have you mixed the cold water in as you fill? i reckon all the heavy sugar etc is staying at the bottom. mix thoroughly (can't be too thorough), take SG sample, then sprinkle yeast on top.


I think KEG is right.
Are you drawing off a sample from your tap, or are you just putting the hydrometer into the top of your fermenter?
If the latter, you are likely to be measuring water rather than anything much else.
Make sure you have thoroughly stirred the brew to evenly distribute the sugar and the kit contents. They will take a while to dissolve before you can get an accurate measurement.

Re: Weird SG Reading on Coopers GB

PostPosted: Friday Feb 29, 2008 11:11 am
by rwh
Yep, sounds like a stirring issue to me. I wouldn't worry about it, it'll all dissolve over time, should come out fine.

Re: Weird SG Reading on Coopers GB

PostPosted: Friday Feb 29, 2008 11:37 am
by drsmurto
Kevnlis wrote:Did you add the yeast nutrient? Yeast is not able to survive on sugar alone.


just cos i am a pedantic mofo this isnt strictly true. I have never used nutrient in either my GBs or ciders and they ferment out fine they just take twice as long!

That said, i do have some DAP to add to my next cider which will hopefully be made from freshly pressed apple juice since its apple season here in the hills. Rumours are i can get it for 75c/L.

If you have any old dry yeasts packets lying around they can be added instead of the nutrient when boiling up the sugars.