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That's what i thought as well... but if that's the case then it would be difficult for me to measure the rate in which the alcohol oxidises to form acid... then again i wouldnt know as to whether acids are actually formed or not... But i did test the ph after one day after exposiing it to air and it was approx 3.03 whereas the initial ph was around 4.77... so yea im trying to find out a way to find out the amount of acid...

Hmmm here's what actually happened in the labs today as i tried to find out the amount of acid present within beer initially... I attempted using an indicator which totally blew it didnt work one bit and then i went on to using PH to find out the amount of acid that is present by titrating with a weak base. As the end point would be completely uncertain as it would be a basic ending ( titrating a weak acid [assuming acids in beer are all weak] with a strong base). I tried finding the PH curve to it but ended up more or less with a straight line and it's strange why there would be a linear line with a acid - base reaction PH curve...

Can someone answer my querie whether alcohols in beer under the influence of bacteria will oxidise to form aldehyde or will it fully oxidise to form ethanoic acid?

Oooo... sorry my knowledge of chemistry is rather limited... i didnt know carbohydrates get oxidised too... sigh i guess the KMnO4 would be useless then... so i'm thinking of using the website i gave by evaporating the amount of ethanol in beer but for that to happen i guess i need to have a quenching reagent for it to stop at the allocated time.

Hmmm, okay here are some of the problems im facing at the moment with my experiment. I have no intentions of changing my topic so yea... I'm gonna stick to it and figure out how i'm actually going to get results! First of all, i tried to find out the concentration of ethanol within beer by attempting to oxidise it using potassium maganate (but surely the sugars in beer will be reacting with it as well, i thought of just stating it in my error analysis), and back titrating with hydrogen peroxide to find out the amount of potassium maganate used so as to calculate the amount of ethanol present within beer. But when the reaction creates a brown sludge like substance which i cant work with as such i cant find out how to get the amount of ethanol present within beer. But i've found this website which shows how to get the amount of ethanol out from beer but now i need a quenching reagent which i cant seem to find. The site for this particular method is http://www.outreach.canterbury.ac.nz/chemistry/ethanol.shtml Secondly, I think this is more successful, i've tested the P.H of the beer at the initial stages which is approx 4.78 or so (this is half and hour after it has been exposed to air) and the beer P.H after 24 hours is around 3.01. So i know that it is possible but tedious to find out the rate of production of acids within beer. The only problem that i'm facing is the titration, as i'm using relatively pure sodium hydroxide so as to compeltely react with the weak ethanoic acids and with phenolphthalein as an indicator, the only problem is the colour change, which might be a bit inaccurate as the colour change in beer is not that significant compared to a normal acid-base titration where the colour change is obvious. As such if anyone has any advice on such a topic do help please any help is greatly appreciated! Thanks Dr.DNA for your help it helped me think through certain things

Hi, i've read the other posts on the oxdiation of alcohols in wine and i find it very interesting, however contrary to his experiment im attempting to design and conduct an experiment whereby i find out the rate of oxidation of alcohol in beer. It is known that the oxidation of alcohol in beer (if i leave it exposed to air) is mainly due to the bacteria that is working on it. I do not know how long i should hold this experiment and the way about to do it. If i use some Potassium dichromate or potassium permaganate to instantly titrate it to completely oxidise the solution and backtitrate with hydrogen peroxide ( for permaganate) or potassium iodide and sodium thiosulfate (for dichromate). The colour stands in the way, i have yet to try activated carbon though to see whether it is possible to remove any organic coluring within the solution, but my fear in doing so would be to remove the ethanol which im investigating into. So if anyone has any knowledge over this please do help i'm in serious need for some help