How much does WLP001 attenuate overnight?

[phillip_h]

I brewed a big double IPA yesterday and forgot to take a gravity reading when the brew day was over. I checked it this morning and it was at 1.071. Any idea where it may have started?

 

[sven945]

Did you make a starter? If not then it might have barely started at all. If you did then my semieducated guess would be that it was a bit higher than 1071.

 

[jrgtr42]

did you take other measurements?
Was there any sign of anything going on when you took your sample?
What was your expected SG?
What was your recipe? We may be able to guestimate based on that info, but there's really no way to know for absolute certain.

 

[phillip_h]

15 lbs of 2-row, .25 lbs of C60, 12 oz corn sugar. According to BeerSmith, the gravity should have been 1.089. I made a 2L starter and there was a lot of activity this morning when I took the sample.

 

[jerbrew]

Probably the easiest thing to do is wait for it to finish and work backwards from the average attenuation. If that number makes sense then go with it. Also, and this is more complicated. you can take a few readings along the way to being finished and guestimate where it started by fitting an exponential curve to your data points and interpolating out to day/hour 0 as your starting gravity. That in conjunction with the average attenuation might get you close.

 

[bajaedition]

Totally depends on cell count

 

[phillip_h]

I know that there's really no scientific way to determine what the actual OG is; I'm just wondering if anyone has checked the gravity of their wort the next day and found that it had dropped a point or more.

The wort should be very fermentable. There's almost a pound of corn sugar in there and I mashed at 150°F. I made a 2L starter with a stir plate about 48 hrs before pitching, so there should have been an immediate, active fermentation.

I checked this morning (about 36 hrs after pitching) and it's down to 1.038. Is it conceivable that the gravity dropped from the target (1.089) to 1.071 in the first 14 hours?

 

[bajaedition]

Yes

 

[burninator]

What method are you using to check gravity?

If you're using a hydrometer, as I assume you are, and there is a lot of activity happening at the time of the sample, then your reading is going to be off a bit, as suspended CO2 will push up the hydrometer, giving you a lower SG reading.

 

[phillip_h]

What method are you using to check gravity?

If you're using a hydrometer, as I assume you are, and there is a lot of activity happening at the time of the sample, then your reading is going to be off a bit, as suspended CO2 will push up the hydrometer, giving you a lower SG reading.

Yeah, I'm using a hydrometer, and there are a ton of bubbles when I first pour the sample, but I wait 10ish minutes to let the foam dissipate before I take a reading.