Gravity question

[marx102]

So I brewed an amber ale a couple of days ago. Five gallon batch. Used 6 lbs gold LME and a pound of table sugar. According to beer calculus the OG should be in the neighborhood of 1.056 or so. According to my hydrometer it's 1.040.
I added 3 oz of hops at flameout. I also strained the wort through a paint strainer bag.
Is it possible some of the fermentable sugars got trapped in the hops or the strainer.
I shook the carboy for about three minutes before taking a sample.
Thanks
Just trying to figure out if paint strainer bags are working against me.

 

[Jayhem]

Calibrate your hydrometer in distilled water to be sure it's reading right. it should read about 1.000 in distilled water at 60F.

When you do partial boils and add cold top off water it often does not want to mix in with the boiled wort. When I was doing extract beers and partial boils I had very inaccurate hydrometer readings as well.

 

[Revvy]

Was this a top off batch? If that's the case read this.

 

[marx102]

Ya it was a partial boil. I've done 50 batches over the last two years and haven't seen such a large discrepancy before. I thought it was a mixing issue but its impossible to actually know. I'm not really concerned with ABV just want to make good tasting beer. At 50 batches I still consider myself a noob.
I was really hoping that it wasn't the strainer bags because I love using them.
Thanks people

 

[Jayhem]

Was this a 5 gallon batch?

I just entered 6 lbs of gold LME and 1 lb of table sugar into beer calculus and it says OG should be 1.050 for 5 gallons.

 

[marx102]

Ya, I just pulled that number out of my ass, I will admit. I couldn't remember and I didn't have access to my notes.