Low Original Gravity

[hedgehogbrew]

I just finished a brew session in which I had a low OG of around 1.034 when the target was 1.050. I was brewing the Cowboy Alt from Zainasheff"s Brewing Classic Styles. What do people think went wrong to achive the low gravity? There was a slight boil over but not much volume was lost. The recipe is below for reference. This was my 5th batch of extract brewing and have not had much issue hitting the OG previously at all.

1.5 lbs of Crystal (40 deg) Steeped for 30 in at 150 F
6 lbs of Pilsner LME
1 lbs of Pilsner DME


Thanks for the future comments and help.


Side note: This is my first post in the forum, although I have enjoyed reading comments from people for the last few months as I have began to enjoy the art of homebrewing.

 

[slowbie]

Was it partial boil? If so, it's probably because the wort and the top off water rarely mix fully, so the OG reading is often low. With a predominantly extract brew like that, it's nearly impossible to miss the OG unless you add the wrong amount of water at the end. The boilover might have lost you a couple points too, but I would guess it's mostly the mixing thing. And don't worry about having to mix it now, because it all works itself out through fermentation.

 

[Bheher]

Can you post a bit more detail as to your recipe. How much water did you use? Did you do a full volume boil or add water at the end?
Also, seeing as you have brewed a couple batches I assume you know the hydrometer reading needs to be taken at 68 degrees.

 

[hedgehogbrew]

It was a partial boil. I started the boil around 3.5 gal and endup around 3. I added to five at the end. The temp was around 69 to 70 when i took the reading. The not being mixed sounds like the most reasonable explanation. I did my best to shake the carboy for a 1 minute to achieve a good mix along with aerating the wort.

 

[Revvy]

Well in your last few batches you must have done a hellova good job mixing your wort and water, because normally this is a first batch question that gets posted....

It's a pretty common issue for ANYONE topping off with water in the fermenter (and that includes partial mashes, extract or all grain revcipes) to have an error in reading the OG...In fact, it is actually nearly impossible to mix the wort and the top off water in a way to get an accurate OG reading...

Brewers get a low reading if they get more of the top off water than the wort, conversely they get a higher number if they grabbed more of the extract than the top off water in their sample.

When I am doing an extract with grain recipe I make sure to stir for a minimum of 5 minutes (whipping up a froth to aerate as well) before I draw a grav sample and pitch my yeast....It really is an effort to integrate the wort with the top off water...This is a fairly common new brewer issue we get on here...unless you under or over topped off or the final volume for the kit was 5 gallons and you topped off to 5.5, then the issue, sorry to say, is "operator error"

More than likely your true OG is really what it's supposed to be. And it will mix itself fine during fermentation.

 

[hedgehogbrew]

Thanks. I understand operator error is completely possible. This was the first time I used a carboy to ferment in. On every other batch I used a 5 gal pail but didn't want to wait to have a pail free up in order to make more beer.