FG/ABV question - did I do something wrong?

[gridder]

I just bottled a scottish ale from kit by Brewers Best. My OG reading was 1.035 (I had problems taking this reading and didn't stir the wort really well, which in hindsight may have been a problem. It was supposed to be between 1.034 & 1.038). I fermented for 9 days in a primary, and just less than 2 weeks in a secondary. My FG reading today was 1.012, which according to the calculator on the BB sheet comes out to 3.01 ABV. Kinda wimpy! It was supposed to come out to between 3.25 and 3.5.

So, did I leave it in the secondary too long? Move it off the yeast too quickly? I tasted it and it tastes fine, if a little thin. I don't drink a lot of flat beer, so I'll have to wait and see. But, I was curious for any input.

 

[Doc Robinson]

Your numbers seem dead on. With an OG @ 1.036 and a finish of 1.012, you are going to be in the low to mid 3's as far as ABV is concerned. Your fermentation schedule is more or less perfect. If you are looking for something with a bigger alcoholic punch, starting OG is the key. ABV grows proportionally to the variance between your OG and FG.

 

[BillyBroas]

Well if your OG was 1.035 and it was supposed to be between 1.034-1.038 then you're good, no?

On the other end, if your FG was higher than it was supposed be it could be because your beer wasn't done fermenting yet. Did you check it with a hydrometer to know it was done fermenting before you bottled?

Also, your OG could have actually been higher but if you diluted the wort with water after brewing you may not have stirred it well enough, which I think you were referring to.

I've actually made the Brewer's Best Scottish Ale kit and agree that it was a little thin. Overall I wasn't too impressed with that kit.

 

[gridder]

Yes - you are right about the water - that may have been a problem with the OG.

So how do I know what the FG is supposed to be? It didn't say on the kit. Is there a range I am shooting for? (Or do I have to backtrack the math and figure it out that way using the ABV I am aiming for?)

It tastes ok, but I am used to much bigger beers I guess!

 

[Doc Robinson]

So how do I know what the FG is supposed to be? It didn't say on the kit. Is there a range I am shooting for? (Or do I have to backtrack the math and figure it out that way using the ABV I am aiming for?)

Multiply the average attenuation % of the yeast you are using by the starting gravity [((OG - 1) x 1000) x (1 - attenuation %)] = FG*.

*Then obviously FG / 1000 + 1 to convert to 1.xxx format.

 

[anthonyb15fd]

I have a question.. I have seen beer with 6.4% and even 10% ABV.. How do you get those numbers..? Is it because of the beer itself or do you add more of something when making the beer..? I just made my first batch of True Brew Amber Ale and it also came out in the 3% ABV.. Am I missing something..?

 

[BillyBroas]

I have a question.. I have seen beer with 6.4% and even 10% ABV.. How do you get those numbers..? Is it because of the beer itself or do you add more of something when making the beer..? I just made my first batch of True Brew Amber Ale and it also came out in the 3% ABV.. Am I missing something..?

Yep and they get even higher than 10%. Brew Dog just set the record with a 32% beer but I'm sure that will be broken soon.

You were correct with "You add more or something." In general, the more grain you add, the more sugar your beer will have for the yeast to convert to alcohol, and then stronger your beer will be. So if you're making an extract recipe you could add more extract to get a higher alcohol beer.

There are other factors too such as yeast strain and attenuation, but I think this answers your question most directly.

 

[anthonyb15fd]

Thanks, so my next batch is going to be a classic english pale ale, if I want more ABV i can add an extra can of the extract...?

 

[BrewinJack]

do you often use kits? It is in my observation that kits very often don't have enough extract or have instructions which have leave ones OG a bit lacking. I have found that often enough even that when youve completed your boil the OG is fine but when topping off you lower the temp cause a significant drop. Say if your kit says it will make 5 gallons but post boil you only get 4 gallons. You add water to help the wort cool faster before you take your first OG read. Then when your now five gallons is cooled you have just reduced your OG by 20% (say from 1.050 to 1.040) and youve lost a whole percent off your final ABV. This would explain why a beer which would normally be around 4.5% -5% is struggeling to get to 3.5%

I would sugest looking at the recipes on this site and buying your own stock to make it, and to nuts with the kits. If you want to do kits, just grab an extra pound of dry malt or canned malt just to give it a good boost, and alwasy cool your wort and check your OG before adding water. Kits are nice, but they are made by somebody who might not be in possession of all the facts.

Cheers and good luck

 

[BrewinJack]

Thanks, so my next batch is going to be a classic english pale ale, if I want more ABV i can add an extra can of the extract...?

Whats your recipe look like?

 

[jbambuti]

You can't just add extra extract, because that changes the balance of all the other things in your beer. Here's a recipe that I made recently for an English Pale Ale that turned out pretty well.

Steep .5 lbs Simpsons Crystal at about 155 degrees for 30 minutes
1 lb. light DME @ 60 min.
6 lb. Pilsen LME @ 20 min.
.5 oz. Magnum (12.1%) @ 60 min
1 oz East Kent Goldings (5.4%) @ 20 min
1 oz East Kent Goldings (5.4%) @ 1 min
1 packet of Safale S-04 (but Nottingham would work well also)

Leave in primary for 3 weeks and then bottle. Let condition for at least 3 weeks. I also used Whirlfloc during the last ten minutes of the boil, but that's not a necessity.

 

[gridder]

Multiply the average attenuation % of the yeast you are using by the starting gravity [((OG - 1) x 1000) x (1 - attenuation %)] = FG*.

*Then obviously FG / 1000 + 1 to convert to 1.xxx format.

Brilliant! Thanks!

And good to know about bumping up the fermentables. I feel like I made "near beer" instead of beer, and I've got 40 bottles of it conditioning now!

 

[BillyBroas]

do you often use kits? It is in my observation that kits very often don't have enough extract or have instructions which have leave ones OG a bit lacking. I have found that often enough even that when youve completed your boil the OG is fine but when topping off you lower the temp cause a significant drop

Hey Jack, can't say I've had the same experience with kits coming in under their stated OG. They rate them for a certain volume, typically 5 gal, and if you come in at 4 gal after the boil then you should have a higher OG than what is stated. After top off to 5 gal, it should equal the stated OG. I'd hesitate to add extra malt extract before I knew for sure a certain type of kit was consistently coming in low.

Also if you take the OG reading before you dilute, then you are going to have the wrong OG reading. Unless of course you do the math to factor in the water you add, but I'd recommend just mixing really well and taking then taking the reading to keep it simple.

You're right about the kit instructions though, they're always lacking.