Checking my fermeneter

[adamgm]

Hey all,
just checked my mixture in the fermenter. It has been in there for about a week and a half.
I read my specific gravity to be about 1.12 but the % (this is alcohol percent, right?) to be only about 1.5%

According to the intsructions, I should probably be bottling now because it's been about 3 days with no bubbles in the airlock. I only recently got the tools to read the specific gravity, but the alcohol percent seems weird. Will that change yet?
I'm considering reading it again tomorrow and maybe bottling then if I get the same reading.

Thanks!

 

[Newsman]

You have to know your *starting* gravity as well as your current/finished gravity. If you don't know your starting gravity, some of the more advanced folks here can help estimate what it should have been.

 

[flars]

The % alcohol scale on a hydrometer is mainly used in wine making. There is a formula for calculating ABV, but I always forget what it is, so I use a calculator. Original Gravity and Final Gravity are needed for both. The estimated OG can also be found by using the ingredients of the recipe.

This calculator is for ABV.
http://www.brewersfriend.com/abv-calculator/

Estimated OG can be found by using a recipe builder.
http://www.brewersfriend.com/homebrew/recipe/calculator

edit: Don't go by a calendar or air lock activity to determine when fermentation is done. Stable SG readings over a few days, most times, is the only way to know when the fermentation is complete. Some yeasts will take a week to finish the final couple SG points.

 

[RobertMT]

Your reading is more likely 1.012 and could be done, depending on style. The 1 1/2% is potential alcohol remaining. Reread instruction on hydrometer. http://beersmith.com/blog/2011/03/18/using-a-hydrometer-for-beer-brewing/ worth while read.

 

[eadavis80]

Depending on your beer, your FG should GENERALLY be somewhere between 1.020 and 1.010, but there are a zillion factors which influence this. Don't bottle until your gravity doesn't change for at least 3 days. If you do, you'll risk "bottle bombs" which can be very, very carbonated bottles of beer and at worst - exploding glass bottles which can be very dangerous. I have never bottled a beer until it's been at least 3 weeks since I brewed it just as a general rule of thumb. Others will say they've gone from kettle to glass in less than 2 weeks. To figure your ABV, you take your OG (which it sounds like you didn't take, but can figure out online if you know your recipe) - FG (the gravity that doesn't change over 3 days) and multiply that difference by 131.5. Hope this helps.

 

[adamgm]

Oops, yeah, I meant 1.012.
My starting was around 1.046

 

[Newsman]

Oops, yeah, I meant 1.012.
My starting was around 1.046

There's a good chance it is done. However, to be sure, you should take the gravity several times over a period of several days. If it doesn't change over three consecutive tests (over a period of about a week) then it's done.

 

[ncbrewer]

IMO it's a good idea to minimize the number of times you open the fermenter. I check gravity 2 - 3 days before I plan to bottle, and again on bottling day to be sure it's stable.

 

[Newsman]

IMO it's a good idea to minimize the number of times you open the fermenter. I check gravity 2 - 3 days before I plan to bottle, and again on bottling day to be sure it's stable.

I have a plastic BMB, so I just drop the hydrometer in there and leave it the whole time.