Can't believe I'm asking an OG/FG question.... help?

[DSorenson]

my first created recipe:

6 lbs pale DME
1 lb Caramel Malt (40 lovibond) steeped
3 ounces perle hops (divided evenly at 60, 15, 0 mins)
Nottinghams Ale yeast

For lack of a wine thief (somehow lost it before the crucial moment), I used a bit of scotch tape and sewing thread to put the hydrometer in the carboy assuming this was better than nothing. It read 1.030 which I figured was low due to the weight of said added materials. I tried to make sure I wasn't lifting the hydrometer. I just now did a test with the same materials to find my reading was probably off by 0.005 on the low side. I tried to keep everything the same. Right now after 2 weeks and 3 days I have a reading of 1.010 (using a proper wine thief). After doing the math, my ABV comes to 3.28 percent by volume. A huge disappointment from the 5 % I was looking for. Anyone have any help for me?

The formula I used: ABV% = (1.05 * ( OG - FG ) / FG ) / 0.79

 

[Hogarthe]

was this a 5 gallon recipe? I think your og should have been closer to 1.055, which would mean you'd be at a much higher abv %

 

[duboman]

What was the recipe's stated OG? What was your measured OG?

Many times the brewer's reading is off from the recipe when doing an extract batch due to the poor mixing of wort and top off water so you should use the recipe's stated OG. I will assume this is where your skewed reading is coming low from. If the recipe stated a 5% beer and you finished at 1.010 It's probably a 5% beer!

 

[DSorenson]

It was a recipe I created based on quantities I've done for IPAs using 7.5 lbs pale DME which yielded about 6.6 ABV. I assume Pale DME provides fermentables on a linear basis, so by doing a little ratio work, I figured out that 6 lbs would get me in that 5 - 5.5 range.

I suspect I didn't mix the top off water well enough...

Also, I took my first "terminal" reading today. I hope by tuesday taking another will yield the same reading so I can hurry up and bottle it. Tasted the sample, sweetness I would expect from using caramel malts, not highly flavored, nice hop presence.

Hogarthe: it is a five gallon batch! That estimated number you're giving me seems WAY better. where did you get that one?

 

[Pie_Man]

DME has about 42 gravity points per pound per gallon.

6 pounds * 42 = 252 total gravity points.

252 / 5 gallons = approx 50, or 1.050 OG

Your OG calculation had to be off. If you add top off water, this is the most common cause.

(1.050 - 1.010 ) * 129 = 5.15 ABV

 

[BandT]

Did you top off with water in the carboy and then take the OG measurement? If it wasn't thoroughly mixed first, your reading would be off. I've also heard about residual CO2 in the sample throwing off readings, but I don't know if this would apply in your case.

I would say the only way to tell for sure is to drink a six pack of it, then drink a six pack of a 5% beer to compare

 

[Hogarthe]

I plugged the recipe into the calculator at tastybrew.com it came up at 1.056, actually.

 

[Pie_Man]

I plugged the recipe into the calculator at tastybrew.com it came up at 1.056, actually.

The gravity contribution of DME varies between manufactures. It typically ranges between 40-43 gravity points ppg. I used 42, the online calculator must assume 43. We're both right, I was just trying to show the OP how to calculate their OG manually when using extract.

 

[DSorenson]

Thanks so much guys. In retrospect I see my mistakes. Thanks as always for sage wisdom!!!!