Alcohol volume not right

[Motorbikeman]

I did my first all grain last week. 

This is exactly the recipe I used.   

http://www.brewmate.net/recipes/a8MqaiJMSp6tWrvuUyXY.xml

After nearly a week of fermentation I seem to be getting 1.006  and not the expected 1.013.    At the moment I have an ale over 5% and climbing by the looks of it.   

Why do you think it is so high when the brewmate recipe and the book that I loosely based it on give it around 3.8%. 

I dont fully understand what is happening.  I also dont understand the efficiency %  .     I used a blender and not a crusher, which gave me a small amount of flour. ( crushing device on the wish list)    Could this be the reason?

It tastes lovely by the way.    A good start for sure.   

[alealex]

Did you stick to your mashing temp?
I don't think blender has anything to do with it, it would rather have to do with filtration/clarity or efficiency.

[Motorbikeman]

the strike temp was 72 and dropped to 67.  I lost a few degrees over the hour then.    I did boil off more water than I intended and ended up with a little under 18L  .   I was supposed to have 18.7L   

The boil was quite vigorous even with one element on.

[alealex]

was the gravity readin the sameas in the recipe?
or else Im thinking of false temp reading at mashing

[Motorbikeman]

Thats what I dont know as the recipe had no expected original gravity.

It also did not have the carahell grains which are quite sweet I think.  They smelled very sweet anyway. 

The temps where fairly ok although I am using a brewing thermometer  and not a probe type electrical one .

How does the temp effect the ABV%?       

Sorry for the questions.  Im very new and dont fully understand the chemistry behind brewing.

[Dr Jacoby]

First thing to check is whether your measuring device is calibrated properly. Are you using a hydrometer? If so, you should calibrate it by following this procedure.

1.006 is a very low final gravity for an all malt beer. To achieve this density you would avoid using too many speciality malts, mash at a very low temp (i.e. low 60's), oxygenate your wort very thoroughly, use a large pitch of highly attenuative yeast, and ferment at a high temp (say, 22C). Even by doing all of these things you would probably still struggle to get down to 1.006. That makes me think there may something else at work in your beer, maybe a wild yeast infection. Then again, you did say it tasted nice so I can't be certain that's the cause. It's very hard to judge what might have happened without all the details.

[Motorbikeman]

Thanks for that.  I took another test just now and it is sitting at 1004 and still bubbling. 

I added to much yeast.  I was trying to pinch  a bit in the bag while sprinkling on the wort , but the lot went in from the full sachet.   

We live and learn.   Maybe that with the boil reduction in water volume and my wayward stumbling process, I caused it.  I did not have a wort chiller and used a bath to cool which took 2 hours .   

Lots of little things that were not done accurately maybe to blame.  Although I was fairly sure i was in the ball park with my measuremnts and weights. 
    It was a first attempt .     I would love to stand in on an experienced beer makers brew.