Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: neilep on 19/06/2008 13:40:08
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Dear Alcys, imbibers of alcohol and peeps who know about stuff,
As a sheep I of course am just a tea-totaller.....so when I see drinks like these ....
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I think ....." hmm pretty colours...I wonder which I could ewese to bleach my fur with "
What I'd like to know though is how do the peeps who know, know how much alcohol is in each drink ?...is it like a litmus test kind of thing ?..or is it just a matter of ' here's the flavourings, here's the alcohol, therefore total drink minus flavourings must equal amount of alcy in it '...
...and why is it called ' proof ' anyway !!
Thank Ewe (hic !)...you're my beshtest frend...(hic !) [:o)]
Neil
Tea Totaling Wooly Thing
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A simple, even if not extremely precise, test is done with special instrument called Alcoholometer which is an Hydrometre specifically used for alcohol:
http://en.wikipedia.org/wiki/Hydrometer
Here you have a better picture of that instrument:
http://www.vebi.it/enologia/092.php
You put it in the liquide's container and it goes down of an amount which depends on the liquid's density, which, in turn, depends on the alcoholic concentration (if there aren't other compounds apart from alcohol which can significantly change the density); then you read the alcoholic conc. directly on the instrument's rod.
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Neily it tells you on the bottle what percentage alcohol some may be 12% or 100 proof meaning straight alcohol There is by volume or per bottle..I believe!
Technically I don't know how they measure it...when making it.. but I am only referring to the patron who purchases it!
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100% proof means there is 57% alcohol, by volume.
Why 57%? Because you could test for 'proof' by setting fire to gunpowder soaked in 100% proof rum. Any less and it wouldn't burn.
So, with 100% proof, you're only just over half way there to 'straight' spirit!
It is amazing that very high proof spirits have an effect out of all proportion with their strength. It must be to do with the alcohol boiling off in your warm mouth and getting into your system via mouth and nasal tissues, I think.
Ever tried 'sniffing' vodka? Instant effect - pow! But makes you sneeze.
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if there aren't other compounds apart from alcohol which can significantly change the density;
then you read the alcoholic conc. directly on the instrument's rod.
Compounds like sugar...
A saccharometer is a hydrometer used for determining the amount of sugar in a solution. It is primarily used by brewers and winemakers.
http://en.wikipedia.org/wiki/Hydrometer
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100% proof means there is 57% alcohol, by volume.
Why 57%? Because you could test for 'proof' by setting fire to gunpowder soaked in 100% proof rum. Any less and it wouldn't burn.
So, with 100% proof, you're only just over half way there to 'straight' spirit!
It is amazing that very high proof spirits have an effect out of all proportion with their strength. It must be to do with the alcohol boiling off in your warm mouth and getting into your system via mouth and nasal tissues, I think.
Ever tried 'sniffing' vodka? Instant effect - pow! But makes you sneeze.
OOOOH I did not know that.. I thought 100 proof was straight.. very interesting Thanks!
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lightarow
Hi, again.
When you are brewing, it it far easier to measure the Specific Gravity of the initial malt solution. It's called the Original Gravity ('OG') and is quite high compared with the final SG, after fermentation is complete. You use a simple Brewing Hydrometer which has, in addition to the OG scale, a scale telling you the final alcohol content, assuming it has fermented out completely. It's best to read it then because you will see two or three different scales once you have started to drink the shtuff.
I should imagine that, because the final SG is so near unity that the error in measurement of the actual alcohol content is more subject to error. Other additives would make more of a difference, as in your quote.
neil
Are you expecting a delivery of that lot next Tuesday, too?
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A simple, even if not extremely precise, test is done with special instrument called Alcoholometer which is an Hydrometre specifically used for alcohol:
http://en.wikipedia.org/wiki/Hydrometer
Here you have a better picture of that instrument:
http://www.vebi.it/enologia/092.php
You put it in the liquide's container and it goes down of an amount which depends on the liquid's density, which, in turn, depends on the alcoholic concentration (if there aren't other compounds apart from alcohol which can significantly change the density); then you read the alcoholic conc. directly on the instrument's rod.
Awesome !!!..Thank EWE Alberto
I specifically like the second picture because it's on an Italian site and as ewe know ..I luff Italy !!...and as a sheep..I am of course fluent in Italian !!.....merci !! (LOL)
Seriously though..thank you for the great links ...very interesting !!
Crikey !!..I would NOT want them to test the specific gravity of me using that thing !!
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Neily it tells you on the bottle what percentage alcohol some may be 12% or 100 proof meaning straight alcohol There is by volume or per bottle..I believe!
Technically I don't know how they measure it...when making it.. but I am only referring to the patron who purchases it!
Thank EWE Kareny Mam ....so that's how they know how much alcy is in the drink...because it says so on the label !!.......hee hee !!..
You managed to highlight a failing in the way I worded the post....It's my fault for not explaining it better....what I meant was how do they determine the alcohol content ?
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100% proof means there is 57% alcohol, by volume.
Why 57%? Because you could test for 'proof' by setting fire to gunpowder soaked in 100% proof rum. Any less and it wouldn't burn.
So, with 100% proof, you're only just over half way there to 'straight' spirit!
It is amazing that very high proof spirits have an effect out of all proportion with their strength. It must be to do with the alcohol boiling off in your warm mouth and getting into your system via mouth and nasal tissues, I think.
Ever tried 'sniffing' vodka? Instant effect - pow! But makes you sneeze.
WOW !!..Thank Ewe sophieCentaur ...are ewe saying that me ...as a hater of alcohol**.....can enjoy getting drunk by sniffing vodka ? (hic !) ..I appreciate your explanation of 'Proof' !..Thank you !
**This is not a principle thing ..I just hate the taste !!
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if there aren't other compounds apart from alcohol which can significantly change the density;
then you read the alcoholic conc. directly on the instrument's rod.
Compounds like sugar...
A saccharometer is a hydrometer used for determining the amount of sugar in a solution. It is primarily used by brewers and winemakers.
http://en.wikipedia.org/wiki/Hydrometer
Thank EWE RD..great info !!
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lightarow
Hi, again.
When you are brewing, it it far easier to measure the Specific Gravity of the initial malt solution. It's called the Original Gravity ('OG') and is quite high compared with the final SG, after fermentation is complete. You use a simple Brewing Hydrometer which has, in addition to the OG scale, a scale telling you the final alcohol content, assuming it has fermented out completely. It's best to read it then because you will see two or three different scales once you have started to drink the shtuff.
I should imagine that, because the final SG is so near unity that the error in measurement of the actual alcohol content is more subject to error. Other additives would make more of a difference, as in your quote.
neil
Are you expecting a delivery of that lot next Tuesday, too?
If ewe care to join me in North London..I'll order a batch just for ewe.....for next Tuesday !!. [;D]
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Keyring Breathalyser £8.95.
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The smallest breathalyser in the world. Our keyring breath tester will allow you to check whether you are safe to drive after drinking alcohol. It also has a built-in high brightness LED torch. 3 Level Measurement : * Level 1 (Green light illuminates). Blood Alcohol Content (BAC) is lower than 0.05% (0.25mg/L BRAC). Safe to drive. * Level 2 (Yellow light illuminates). Blood Alcohol Content (BAC) is between 0.05% (0.25mg/L BRAC) and 0.079% (0.39mg / L BRAC). Safe to drive but may be wise to call a taxi. * Level 3 (Red and Yellow light both illuminate). Blood Alcohol Content (BAC) is above 0.08% (0.40mg/L BRAC). Call a taxi - You are over the limit to drive ! 0.08% BAC is the current UK drink drive limit This product is not to help you see how much you can consume and still drive - it is there to make you think “Should I be driving?” In no way do we promote drink driving - This unit is to aid you into making an informed decision. We accept no liability arising from the use of this product.
http://www.shopblue.co.uk/product346926/product_info.html?utm_source=google&utm_medium=base&utm_campaign=google%2Bbase
Cheap enough for an experiment, but I wouldn't gamble my driving licence on the accuracy of a device costing less than a tenner.
Could come in handy to convince a bladdered party guest that they are unfit to drive.
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OK, so it says on the label. But how do they know what to put on the label. Well, the official method is to distill a known volume of the stuff, take the distillate (which will have practically all the alcohol) and dilute it back to the volue you started with. Then you measure the density of the diluted distillate with a hydrometer or an S.G. bottle and a decent balance.
Then you look up what alcohol concentration corresponds to the denstity you measured, at the temperature you are working at.
The distillation removes acids, sugars etc that would mess up the density.
If you are making beer or wine, there are tables that tell you the expected alcohol concentration for a given density of the starting material. If you need better accuracy you can measure the density before and after fermentation, the difference (so called "lost gravity" is a better predictor of the final alcohol content.
Or, you can do what I did and run the stuff through a gas chromatograph.
btw "but I wouldn't gamble my driving licence on the accuracy of a device costing less than a tenner". What about gambling your life?
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Or just see how much it takes to make you fall down. If you can still count then it's not very strong.
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I never have problems with counting, now getting back up thats another thing!
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I never have problems with counting, now getting back up thats another thing!
and Bee knows a thing ot two about alcohol.
http://www.thenakedscientists.com/forum/index.php?topic=6730.msg76350#msg76350