og way too low

[Melnyk]

i brewed a 4 gallon stout and my og was supposed to be 1.102 bout my measured og was 1.062 i hit my mash temp perfectly in 11.25 qt of water of 152 degrees for 30 minutes and sparged in 8 qt of water for 20 minutes at 170 degrees, my grain bill was

4.00 lb Amber Dry Extract (12.5 SRM) Dry Extract 30.77 %
6.00 lb Pale Malt (2 Row) UK (3.0 SRM) Grain 46.15 %
1.00 lb Caramel/Crystal Malt - 40L (40.0 SRM) Grain 7.69 %
1.00 lb Chocolate Malt (350.0 SRM) Grain 7.69 %
0.50 lb Barley, Flaked (1.7 SRM) Grain 3.85 %
0.50 lb Oats, Flaked (1.0 SRM)

do you think this was from my mix water or did i just mess my mash up?

 

[smagee]

From some quick calculations in Beersmith, your numbers were approximately correct (assuming a full boil, standard sparge, etc). From what I can tell, the only way you could've gotten that OG is from undermixing before checking gravity. How thoroughly did you stir/blend before drawing a sample?

 

[Melnyk]

From some quick calculations in Beersmith, your numbers were approximately correct (assuming a full boil, standard sparge, etc). From what I can tell, the only way you could've gotten that OG is from undermixing before checking gravity. How thoroughly did you stir/blend before drawing a sample?

I mean I thought I stirred well for about 2 minutes and shook the carboy to aerate I did have more trub than expected in the bottom about maybe 3/4 of an inch worth

 

[smagee]

I'd expect that to be enough, but some here advocate stirring for a solid 5 minutes before sampling. That said, it still shouldn't be *that* far off. Your final volume was still 4 gallons?

I'd suggest taking another sample just to verify (assuming you haven't already been fermenting for some time). Barring that, my only other thought would be that omitting either the DME or the pale malt would bring you to about that gravity, so silly as it may sound, are you sure you added everything listed?

 

[Melnyk]

Yeah it was four gallons and I added everything. Maybe my thermometer is off or the trub concentration threw the reading off. I took a sample after it was fermenting and I actually got a reading of 1.050 with a lot of foam. Well see how she tastes in a few weeks I guess. I'm starting to think my thermometer is reading 10 degrees lower.

 

[smagee]

It's possible. While you're at it, calibrate your hydrometer too, just in case. Fingers crossed that regardless of how much booze it has in it, it tastes great!

 

[Melnyk]

Yep my thermometer is off tested it against an alcohol one mine is digital and my mash temp was probably more like 145 probably didn't get conversion. Well poop live and learn I guess. It will still get you drunk but it's going to be more like an ipa in hoppiness now.