unusual OG

so I just finished brewing a batch of american pale ale, see recipe below....
however when I took an OG reading it said 1.026! The predicted OG from www.beertools.com and my own calculated OG should be up around 1.042! Even if you remove the specialty grains and only add 5lbs of the 6lb container, the OG should still be around 1.035! It's only when you get down to about 4lbs of LME that is says I'd get an OG of 1.028.....and I scraped the inside of the jar out, so there's no way I misplaced 2lbs.
There was nothing unusual at all in the brew, so I have no idea.
I'm thoroughly bemused as to why this would happen - any ideas anyone?
happened to anyone else before?

Malt extract: 6lbs Muntons Light, unhopped LME

Specialty grain: 0.35lbs English grain CaraPils Dextrin malt
0.25lbs Crystal Malt 10’L

Bittering hops (60min): Cascade 1oz (6.7 AAU)

Flavoring hops (30min): Kent Goldings 1oz (5.3 AAU)

Finishing hops (10min): Perle 1oz (5.9AAU)

You didn't mention the temp when you took the reading.

It's calibrated for about 59 F (I use 60 because the math is easier).

Chances are that's what's wrong with your reading....

homebrewer_99 said:

You didn't mention the temp when you took the reading.

It's calibrated for about 59 F (I use 60 because the math is easier).

Chances are that's what's wrong with your reading....

Click to expand...

hi mate
yes the temp correction issue is true, I didnt correct for that. However, I measured it at 77F, but that means I should have a correction of only +0.001! I need to make up a good 0.018 on this.....so temperature isn't going to cut it. It seems as though I'm way too dilute somehow.

drvodka said:

hi mate
yes the temp correction issue is true, I didnt correct for that. However, I measured it at 77F, but that means I should have a correction of only +0.001! I need to make up a good 0.018 on this.....so temperature isn't going to cut it. It seems as though I'm way too dilute somehow.

Click to expand...

now i'm confused - I've just read elsewhere that i have to add two degrees to my hydrometer reading (i.e. making it 1.046) when measuring at 80F, so at 77F, I should be about right. thats pleasing, but why on earth does my hydrometer chart that comes with the hydrometer have incorrect temperature conversions?!?! weird.

thanks for the help, at least I can now sleep easy.....

Not sure, but your numbers seem more on track for the malts you used if you have only 5 gals.

I've never really trusted them (but I use them all the time) because a piece of paper in a glass tube surely can't be a proper calibration method.

I've tested mine. At 60F in water they're supposed to be at 1.000, but that'll never happen so you need to realign the chart inside the hydrometer to what you think 1.000 really is for you. Meaning, your 1.000 at 60F may be 1.012.