OG question -- left sample for awhile

[DCBrewer]

Was in a big hurry today. Post boil, I drew my sample and set it aside. I loaded my fermenter and pitched the yeast, and left for 3.5 hours. Came back and took the OG reading and it was higher than expected (the volume going to the fermentor was expected volume). The anticipated OG was 1.055and actual was 1.068 (hydrometer and double checked with refractometer). Could it sitting for that long mess with the OG? Thanks

 

[toast]

Did you draw the sample while it was still hot? If so, the difference in temperatures could have affected the readings.

**EDIT** My bad, I read your post wrong. I thought you took a reading before and then set it aside and read it again hours later. Sorry for the confusion.

 

[badbrew]

did you boil the extract for a long time? (assuming extract)

 

[DCBrewer]

It was all grain. 90 minute boil (Jamil CA Common recipe) was called for, and that's what I did.

 

[gmcastil]

Was in a big hurry today. Post boil, I drew my sample and set it aside. I loaded my fermenter and pitched the yeast, and left for 3.5 hours. Came back and took the OG reading and it was higher than expected (the volume going to the fermentor was expected volume). The anticipated OG was 1.055and actual was 1.068 (hydrometer and double checked with refractometer). Could it sitting for that long mess with the OG? Thanks

I'm relatively new at this, but do you know what temperature you took your OG at? In my brewing log, I measure both the temperature of the sample as well as the gravity each time I check it. You might be comparing apples to oranges if the expected OG was for a different temperature than you tested yours at.

Also, it looks like you measured your gravity after pitching your yeast. If you used a yeast starter with a lot of volume, then that might account for the discrepancy.

 

[DCBrewer]

Thanks. I'm pretty new at this myself (obviously). I pulled the sample before I pitched the yeast -- and then let the sample sit for 3+ hours in my garage. The temperature came down to an even 60 degrees, so no adjustment should be necessary.

One other factor I should mention. I was brewing outside yesterday and it was cold. My target mash temp was 152. After 20 minutes, the temp was 151. After 40 minutes, it had dropped around 142. I added hot water to bring the temp back up and it was 150 after 60 minutes. Maybe the lower temp for a period of time had something to do with it?

 

[helibrewer]

Lower mash temps will increase your fermentables and could very well give you a higher OG than recipe design indicates. I think you are fine for just pressing on. The lower mash temp will also make the beer a bit thinner so do not dilute the wort just to bring the gravity down.

 

[beerman0001]

I'm guessing you did not take a preboil OG? The sample you took sounds accurate so it will be a bigger beer then you expected.

 

[TipsyDragon]

Sounds like this was an all grain batch you didn't really mention. If so you just got higher than expected efficiency from your system. Nothing to worry about. If this sort of thing happens regularly you can actually start using less grain in your mash which will save you money.

If this was not all grain it's posable you drew the sample from the bottom of the pot. Sometimes the extract will settle there and give you a falsely high reading.

In any case you have a potentially stronger beer than expected. RDWHAHB.

 

[Yooper]

Lower mash temps will increase your fermentables and could very well give you a higher OG than recipe design indicates. I think you are fine for just pressing on. The lower mash temp will also make the beer a bit thinner so do not dilute the wort just to bring the gravity down.

Could you please explain that further? I've been brewing a long time and never heard that before. I know that lower mash temps will increase the fermentability of the wort, but it will certainly NOT affect the OG. Same OG whether you mash at 145 or 160. But the FG may be different, and the body of the beer will be different.

 

[beerman0001]

Could you please explain that further? I've been brewing a long time and never heard that before. I know that lower mash temps will increase the fermentability of the wort, but it will certainly NOT affect the OG. Same OG whether you mash at 145 or 160. But the FG may be different, and the body of the beer will be different.

Thats how I understand it.

 

[Dan]

Was in a big hurry today. Post boil, I drew my sample and set it aside. I loaded my fermenter and pitched the yeast, and left for 3.5 hours. Came back and took the OG reading and it was higher than expected (the volume going to the fermentor was expected volume). The anticipated OG was 1.055and actual was 1.068 (hydrometer and double checked with refractometer). Could it sitting for that long mess with the OG? Thanks

"Could sitting that long mess with the OG?" Are you thinking evaporization might have caused the OG to be higher? That might be possible but not probable. Did you note the initial volume of your sample and the volume after 3.5 hours. Were they the same? I wouldn't think cooled wort would evaporate enough in that short time to cause a significant difference in gravity. But I have nothing to back up that assumption.

You said you met your expected volume and you measured at 60 degrees with a hydrometer and refractometer and I assume they gave you the same reading. I think your brew house efficiency was just better than assumed. Note it and use on your next all grain batch Cheers!

 

[DCBrewer]

Dan -- Evaporation wasn't my theory. I really didn't have a theory! Thanks all for the responses.

 

[BOBrob]

Good grain crush and very good efficiency, along with the 90 min. boil worked like magic to get the 1.068 OG. the hydrometer is measuring sugar not liquid. Like Yooper said the FG may change, but no big deal. It's how you made the beer and how much you like it. I can make the same brew and get different numbers most of the time. Good job, Cheers