Estimated Original Gravity

[Fencemaker]

Howdy, Folks,

First of all, let me say how informative and enjoyable I have found this forum since I started brewing 2 months ago - you guys (and SWMBO's) are great!

So, I brewed my fifth batch tonight. I typically have purchased kits from the LHBS and followed them to instruction. BUT, my OG tends to be a little lower (5 - 15 points) than the recipe advertises. I suspect there is one of three things going on:

1. The OG is over-estimated in order to sucker me into buying

2. I need to measure my water additions more carefully

3. I'm not mixing well enough before taking measurements

Curious to know what the more experienced brewers think...

Thanks in advance! And thanks for the awesome forum!

 

[mbird]

I would like to see the ingredients and quantities to get an idea what is expected from the recipe. Thanks
www.backyardbrewer.blogspot.com
www.thebackyardbrewer.com

 

[C-Rider]

3- sounds like it could be the problem.

pop your recipe into Beersmith (free trial) and see if you come out matching the LHBS figures.

 

[jaycount]

2 and/or 3 I would say. Your water measurements: are you going off of the lines on a bucket fermenter? I was having a similar problem in my setup and weighed water by the gallon in my fermenter and found my lines to be a little off.

Also getting a good mix of wort and water helps

 

[Fencemaker]

jaycount: sort of - I'm eyeballing from a gallon jug that is dedicated to that purpose. Perhaps I need to put some exact amounts into the jug and mark them on the outside somehow.

c-rider: haven't tried a calculator program... suppose I should.

I guess my big question is: how much of an emphasis should I put on mixing the wort and the top-off h2o? And what is the prefered method?

 

[Calder]

You probably are not mixing as well as you could be. Don't worry, the yeast will still find the sugars.

It is a good idea to see if the marks on your fermenter are correct.

 

[unionrdr]

Well,to mix the wort & top off water,I pour the chilled wort roughly into the fermenter,then do the same with top off water. Then grab my brewing spoon & spend maybe 3-5 minutes stiring it to a froth. Then take hydrometer sample. Works pretty well.

 

[Revvy]

We get this question every day

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.

 

[unionrdr]

I like the "revcipes" part. hey! Maybe that's what we should title your stickeys!?!

 

[Fencemaker]

Revvy: Ok then, none of the instructions I have followed have really placed that much emphasis on mixing in that final step. I haven't ever mixed anywhere close to that amount of time; a situation that will be remedied in future batches.

In retrospect (it was late and I was about 4 RDWHAHB's in...) the smaple in my thief was much darker toward the bottom than the top and that was probably the case in previous readings.

Thanks for the tip! You truly are the Yoda of the forum.

 

[torque2k]

Keep in mind, the mixing part of this is not only to get an accurate OG reading, you're aerating the wort. The oxygen introduced at this step is essential for healthy yeast production. The more you aerate (that's just "frothing it up", not injecting pure oxygen) at this stage, before you put the top and airlock on your fermentation vessel of choice, the better your fermentation will be.

AFTER fermentation is complete, that's when you DON'T want that air mixture to touch the beer.

 

[unionrdr]

True,but you don't need o2 cylinders to oxygenate wort. Unless it's some really heavy gravity monster. You're not just whipping it up by shaking,pouring roughly,stiring vigorously. I've done them all,& they work. Besides,what do you think froth is? An aerated liquid. So,getting that,you had to have introduced air into the wort,not just the surface if the head of the spoon is on the bottom of the FV while your hand on the handle is on top.
So that's not completely accurate. It's air,not pure o2,unless you burn more money using o2 cylinders. Not necessary to make normal gravity beers.

 

[Fencemaker]

Keep in mind, the mixing part of this is not only to get an accurate OG reading, you're aerating the wort. The oxygen introduced at this step is essential for healthy yeast production. The more you aerate (that's just "frothing it up", not injecting pure oxygen) at this stage, before you put the top and airlock on your fermentation vessel of choice, the better your fermentation will be.

AFTER fermentation is complete, that's when you DON'T want that air mixture to touch the beer.

Right on. I've learned and adapted my process with each batch and now with this final tidbit, I think I can start making some killer brews. The learning process is almost as much fun as drinking the product!!

BTW, the brew in question from last night is currently growling away through its blow-off setup like an angry tiger. Love it.