Ethanol Content in wine (1 Viewer)

[Commerce Freek]

Hi fellow chemists,

I have just been set an open ended investigation into finding the ethanol content in wine. So far i have searched the net with no sucess.
Any ideas?

Thanx

 

[Riviet]

One way that it could be done is by a series of separation processes that will isolate the ethanol as best as possible, allowing you to measure the mass and hence calaulate percentage composition in the sample of wine.

 

[Commerce Freek]

Thanks for answering,
So by using titrations or other methods?

 

[Commerce Freek]

I think I may try and keep it simple.
I think I may do it by heating the wine to just below B.p. which will evaporate the ethanol for about an hour (checking regualarly with a hydrometer to determine when the ethanol has stopped evaporating) and then allow it to cool and measure the weight difference...

What do u guys think? and do u see any problems with this method?

 

[Riviet]

I think it's a decent method, should be fairly accurate as long as you keep the temperature well below 100^oC so no water evaporates, 80s would be a good range. You can easily do this by removing the heating apparatus from your sample or the sample from the heating apparatus and allow it to cool a little.

 

[rama_v]

You can heat the same amount of water and measure the weight difference due to evaporation. Then the total mass of ethanol is equivalent to the mass loss in wine - mass loss in control (i..e the water). This is probably more accurate.

 

[Commerce Freek]

thanx you guys, u have been a world of help...