fermenting sample?

[TacoGuthrie]

I took a sample on the weekend and it was much higher than i thought it was going to be at 1.032.

I forgot/ lazily left the sample with the hydrometer in it in the beer room and went back a couple of days later and noticed it was down to 1.024.

Does it make sense that a sample would continue to ferment? I suppose there is no reason a sample couldn't continue to ferment outside of the carboy.

How much of an indicator is this for the gravity of the beer still left in the carboy? Don't get me wrong I wouldn't say the beer in the carboy is done just because of a 4day old sample, I was just curious.

 

[kapbrew13]

Oxygen breathes life into everything (yeast) my guess

 

[Clann]

It would absolutley keep fermenting if it wasn't done.

 

[TacoGuthrie]

Ya, that's true.

I would guess that the ratio of oxygen:wort ratio is much higher in the sample than the carboy so it would ferment more quickly?

 

[audger]

after fermentation starts, there is zero oxygen in the carboy. pouring the sample into the container would give the yeast enough oxygen to wake back up. this is how you can fix a slow or stuck fermentation sometimes, just transfering it to another carboy sometimes oxygenates it enough to get it going again.

there is some really good yeast info here...
http://www.wyeastlab.com/he-yeast-fundamentals.cfm

 

[dcp27]

it could have still been fermenting, but a few days in the open air is also plenty of time for it to become infected with wild yeast/bacteria which would do the same.

after fermentation starts, there is zero oxygen in the carboy. pouring the sample into the container would give the yeast enough oxygen to wake back up. this is how you can fix a slow or stuck fermentation sometimes, just transfering it to another carboy sometimes oxygenates it enough to get it going again.

thats not realyl true. oxygens role in yeast is for growth, adding any oxygen afterwards is not recommended and leads to off-flavors. transfering can re-awaken the yeast due to getting them back up into solution, not the oxygen.

 

[Haputanlas]

Let your beer sit for another week or so and then re-sample to get an updated reading. You'll probably see the SG drop some more.

You can probably visually see the yeast still working (Although nowhere to the same degree as before)