Hydrometer Question

[Mesa512]

Hello. I have a quick question about a hydrometer.

So yesterday I took a hydrometer reading of my brew and it came out to be 1.032. Today I took a reading and I got 1.020. I am confused. I thought that as time progressed the number would be higher. Can someone explain how the reading on the hydrometer related to fermentation and alcohol content.

Thanks

 

[Brooklyn-Brewtality]

the Hydrometer measures how much sugar there is in the beer. as the sugar is converted into alcohol, the measurement is lowered.

 

[Mesa512]

See that is what I thought, but it doesn't make any sense. Also on my hydrometer there is a measurement for (potential % alcohol by volume). According to that scale my % alcohol went from 5% to ~3%. Is this normal?

 

[ArcaneXor]

Ethanol has a lower density than wort. The more sugars are converted into ethanol, the lower the gravity.

http://en.wikipedia.org/wiki/Specific_gravity

 

[Brooklyn-Brewtality]

Yes, because there is less sugar. the Potential Alcohol measurement only works before any fermentation has begun

 

[ArcaneXor]

See that is what I thought, but it doesn't make any sense. Also on my hydrometer there is a measurement for (potential % alcohol by volume). According to that scale my % alcohol went from 5% to ~3%. Is this normal?

yes - the more sugars get converted, the less there is available to be converted into alcohol. Note it's "potential % alcohol" - to get the actual, you have to subtract the final measurement from the original one.

 

[blackwaterbrewer]

you may want to read up on this in Charlie Papazian's "joy of homebrewing"