Gravity issues...

[Steeev]

Hi all.
Hope Easter was chocolate-malty enough for you.

I just started my second kit brew, a Woodforde's Nelson's Revenge. The question I have is over the Original Gravity.

It says on the side approx 5% abv. And it also states 36 pints.
Due to this, I carefully measured out a total of 36 pints of liquor (or is it liquer? Never mind)

After the trials and tribulations of my last, lazy fermentation, I vigoruosly aerated this one (at one stage by picking up the entire fermenter and giving it a shake - The Hulk's got nothing on me
(It kept blowing the lid off my fermenter for a day and a bit )

Before pitching the yeast, I took a measurement of the OG, which came out at 1042. the instructions state to bottle when fermentation steadies at around 1014.

I read on a website that the way to calculate alcohol content is:
(Original Gravity-Final Gravity) x 0.129

If this is the case, I'm looking at less than 4% abv.

Am I getting something wrong here, or worrying too much? I'm not worried about drinking 4% beer, probably a nice refreshing summer session beer, but more concerned for future brews.

Cheers as always

Steve.

[bitter_dave]

Great equation - I've never seen that before. Your beer will be below 4% though - I've made beers which have an OG of 1040 and finish at 1010, and I know this to be about 4% (3.9% to be precise).

Until someone replies with a more definitive answer three things occur to me:

1) The obvious - are you sure you added the right amount of water?

2) A more trivial point, but may be a small contributing factor, did you rinse out the can thoroughly with hot water to make sure that all the extract was removed? I didn't do this when I made wherry, and I'm sure I must have ended up with a slightly weaker beer as a consequence (I didn't take an OG reading). Despite being a bit weaker, it still tasted mighty fine in the end, as will your Nelson's Revenge

3) Do you know what temperature your wort was at when you did the OG reading? Temperature can affect the the reading, but not to any great degree.

I'm a novice though, so I'm sure others will have other things to add.

[Steeev]

Thanks bitter_dave.

the wort temp was at 20 degrees, and I rinsed the cans with boiling water. Remembering to use oven gloves to pour it this time! (Maybe I should suggest that for the kit making instructions?)

I guess the water must've been wrong, although I did spend an age measuring it out. i may have to borrow something with a higher degree of calibration from my lab I guess.

Making a small mistake on a pint measurement 36 times could lead to a biggish mistake I suppose.

I did mark the side of the fermenter, but it's difficult to see it when the wort has a 5 inch head on it.

Now it's settled, the liquid is below the 5G mark, but hey, that could be out too,

[Jim]

Dave summed it up pretty well! You'll need an OG of 50 or more to get 5% alcohol if your final gravity is 12.

A rough estimate of abv is to divide the gravity drop by 8.

[Andy]

You could let the fermentation continue past the 1014 point and bottle at say 1012. Even then fermentation won't completely stop and you may well end up at 1010 by the time you drink the end product!

OG 1042
FG 1010

gives 4.2 ABV

I've never bottled beer so don't know if the above is sensible advice in this case though

[noby]

I only use my hydrometer reading as a guide.
I have a cheapo-hydro and didn't buy a trial jar, so my readings are often off. This may be the case with yours too. According to my SG readings, I have made beer in the 3.5-4% range, which felt stronger than that when drinking them (unless I've turned into a complete light weight)

As for andy's suggestion, there's no harm in letting it ferment right out (this may get it down to 1010). The priming sugar will , er, prime your beer in the bottle, and give you about another 0.2% or so, so you'll edge up towards the 4.5% mark.

[Steeev]

Thanks fellas.

I'll leave it there until it ferments right down then. Probably taste better with a bit more time spent on it too.

[Steeev]

Thanks DaaB.

Good tip on the campden tablet.. I was crushing mine up and adding it at the end (15 minutes before yeast pitchage), and there was so much froth I was getting a bit paranoid that a bit wouldn't make it into the wort, meaning more shaking for good measure. Good point on infection too, didn't consider that.

I've got a 10L bucket around here somewhere.. Just got to get that old mop out of it..

I've heard nothing but praise for Nelson's Revenge. Should be ready when I get back off holiday. What a coming home present!