First BIAB - Gravity Readings Not Adding Up

[avw0516]

Alright guys... I've brewed about half a dozen 5 gallon all grain batches and wanted to do a trial run in a 1 gallon brew in a bag version for a big beer. I've been having great luck with my normal all grain setup and generally speaking my numbers add up pretty well.

Go figure, I thought this was going to be a breeze and it's got me stumped. My pre-boil gravity was 1.074, after a 90 minute boil where 1.2oz honey and 4oz sugar were added my post boil gravity is reading 38 brix (1.168)?!

What's going on here?

Recipe is as follows (mad elf clone)
3lbs 10oz Pilsen
14.6oz Munich
0.6oz Chocolate Malt
1.2oz honey (boil for 20 minutes)
4oz sugar (at flameout)
.25oz hallertau 90 mins
.25oz saaz 20 mins

Using Wyeast 3787

I'm thinking my refractometer must not work at higher sugar contents? Typically I stick to around 1.065 beers so I've never tested it's accuracy up so high. My pre-boil was dead on what beersmith said and my volumes worked out perfect so the only thing I can think of is that...

Any thoughts would be appreciated.

-Andrew

 

[PADave]

My thoughts......use a hydrometer.

 

[avw0516]

Yeah... I've gotta get one. I've been enjoying the convenience of the refractometer but this episode has made the need for a hydrometer more apparent.

The measurement repeated 4x - but I can't believe that it's accurate. Do the late sugar additions or honey addition have some impact on the refractometer?

 

[bransona]

That is a HUGE recipe for 1gal. Did 1gal hit the fermenter? Or is that the bottling volume?

 

[avw0516]

1 gallon is the bottling volume. It's ~1.25 in the fermenter.

It's intended to be about 12% ABV.

 

[doug293cz]

How well did you stir after adding the flameout sugar? It takes a lot more mixing than you think it does to homogenize solutions after sugar additions. It's possible that your post boil SG sample may have been taken from from a sugar rich portion of the wort.

Brew on

 

[avw0516]

That may be possible... I took the reading a few times but maybe I was just unlucky. I've never added sugar at flameout before so I'm not positive I stirred enough if it really is that resistant to homogenization - I stirred a fair bit though. I pitched the yeast anyways and we'll see what happens.

 

[bransona]

Between thick honey and sugar, that's a good possibility. Guess you'll have to brew another supr high gravity batch and test it out