First 10 gal AG, misssed SG by 14 pts, please help

[Pjilek]

So, I brewed my first 10 gallon all-grain batch yesterday. I broke my hydrometer the week before, and had ordered one, but it didn't show up until this morning. When I took the gravity it was 1.030, it had been fermenting for a few hours, but this seems way too low. According to the recipe, I should have been around 1.044. I realized once I split the 10 gallons into two fermentors, that I had about an extra gallon. I am wondering what I should do with the low gravity. I tasted the hydrometer sample and it tasted great.

The recipe I brewed was biermuncher's ode to arthur guinness. The only change I made was substituting the acid malt with two pint cans of soured guinness. I used a 3 L starter, which was what Mr Malty reccomended. It tasted great, but I am worried that it will only end up around 3% abv, which is pretty low for the style. I could add some dextrose, I do not have access to a homebrew store, so I cannot obtain any DME until Sunday at earliest. Eh, I am worried, I dont want to have 11 gallons of "Light Guinness." Please help me out, this is the recipe

11.00 lb Pale Malt (2 Row) UK (3.0 SRM) 63.8 %
4.25 lb Barley, Flaked (1.7 SRM) 24.6 %
1.75 lb Roasted Barley (300.0 SRM) 10.1 %
0.25 lb Acid Malt (3.0 SRM) 1.4 %

3.00 oz Goldings, East Kent [5.00%] (60 min) Hops 31.2 IBU

1 Pkgs Irish Ale Yeast (WLP004)

Thanks

 

[pompeiisneaks]

that extra gallon means maybe you either a. put in too much water into the mash, or b. didn't boil long enough to evaporate down... Either way, you didn't have enough grain to hit 1.044 w/ one more gallon of water, would be my first guess. You can find on the forums somewhere here about adding DME, but that's something you should do in the boil. You may do okay if you boil the dme w/ some water to pasteurize it and then add it, but I don't know if that would really work well. I'm mostly trying to point out what I think you did wrong... don't worry, it will still be beer, maybe you just made a great session beer

 

[Pjilek]

Yeah, I added two gallons near the end because when I measured my wort towards the end of the boil, it seemed like I only had 7.5 gallons. My measurement method needs to be calibrated. My main issue, based on a abv calculator is that with my SG and Biermuncher's supplied FG, I am only going to have a 2.7% abv stout....Not very stout... I don't know how I should fix this though, I won't be able to get DME until maybe sunday, and I've heard that dextrose my affect the flavor. I wouln't think that dextrose would change the flavor much, because this recipe has quite a roasty, chocolate flvaor that would mask it, but I don't have any experience with it. The original recipe turns is suposed to be around 4.5% abv.

 

[JVD_X]

Boiling up 2 pounds of LME in a 1/2 gallon of water will raise 10 gallons of wort an additional 1.008

 

[ajf]

Another point is that 4.24 lbs flaked barley is a bit much for 11 lbs of UK pale malt to convert. The U.K pale malts do not have sufficient diastatic power to convert large amounts of adjuncts. I never go over 10% adjuncts, although you could probably exceed that a bit, but > 38% is almost certainly too much.

-a.