• Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure.
    Jump in and join the conversation! You can learn more about the upgrade and new features here.

1st Brew in 7 years

D

Derek Toering

Brewer
Joined
Dec 13, 2010
Messages
46
Reaction score
0
Hi.  Had my first brew in a while and included some new technique in the system.  I tried too many different things though, and now can't tell where I went wrong.

Looking for some advice before I rebrew.

OG was 1048 and I have fermented down to 1032  Ferment is no longer active so has not fermented properly.  Things I did differently...

Single step mash.  (Should be fine, but is the first time I have done it so may attribute to the unfermentable sugars) Used Caramalt, wheat malt and pale malt.  Unsure of modifivation levels from Joe White and Best maltz but assumed fully modified.  I typically always did a 2 step mash

Stir plate starter.  Should be fine but it is a point of difference.  I used dme for the medium.  I usually use wort from previous brew for yeast culturing which gives much better result imo.  Didn't aerate the wort as usual but relied on the stir plate.  Conflicting info web if airation is required when using stir plate.

In line wort oxygenator.  Used oxygen cylinder to aerate the wort after the plate heat exchanger.  Typically I used to splash the wort into the fermenter.

After the changes, the yeast initially went mad and I had an overflow like never before.  Possible that I have lost a lot of yeast in this, but repitching extra yeast didn't really do too much so not convinced that this is the issue.

The beer although only at 3.2% is sweet, but tastes good so I rule out infection.  I am leaning toward the single step mash as the issue. 

Appreciate any thoughts before I hit it again.

RIMS system.
 
Just a few questions:

How long has it been fermenting?

You think that the fermentation is over, what leads you to this conclusion?

What yeast did you use?

Your gravity reading is with a hydrometer or refractometer?

More when we get answers to above...
 
Greetings Derek,

My initial reaction is to suggest your yeast has simply stalled out.  This is typical (and problematic) for certain strains of yeast known to stall out at about 1.030.  Another thought I have is pH level.  Is it possible you're beer has become too acidic?  My suggestion is to give your beer a gentle stir and while doing so, take a sample and test the pH.

Another thought is possibly too much oxygen.  Below is a quote from a book by Chris White, White Labs:

"Contrary to what many brewers believe, it is possible to overoxygenate your wort when using pure oxygen. If you provide an overabundance of oxygen, too much growth can occur, creating an overabundance of fermentation by-products and resulting in a less than ideal fermentation character."

Just some thoughts...
 
Oginme said:
Just a few questions:

How long has it been fermenting?  2.5 weeks

You think that the fermentation is over, what leads you to this conclusion?  FG unchanged in 7 days

What yeast did you use? German ale

Your gravity reading is with a hydrometer or refractometer?  Refractometer

More when we get answers to above...
Click to expand...
 
OK, when you are taking your gravity readings with your refractometer, are you correcting for alcohol content?  The  refractometers used for measuring sugar solutions do not account for the lower density of alcohol, so the reading must be corrected.  In the refractometer tool in BeerSmith, you can set the measurement type for "fermenting wort gravity'.  You will then need to enter the original gravity along with the refractometer reading in Brix.  BeerSmith will then calculate out the corrected gravity reading.

So, your present gravity reading of 1.032 would be 8.04 Brix.  When I enter 8.04 Brix as the present reading with an original gravity reading of 1.048, I see a corrected gravity reading of 1.022.  This is still only an apparent attenuation of around 54%.

Unless you mashed at a fairly high temperature, such as 160F or so, this is way too low for a German ale strain, which should be in the 73% to 77% range for attentuation.

So this gets back to what KellerBrauer suggested in that your yeast may have stalled out for whatever reason.  You can (1) try adding a bit of yeast nutrient to see if that will restart the yeast, (2) make a very small starter of that yeast or another strain and add that to see if it will complete the fermentation, or (3) start over again (not always a bad choice).

 
Oginme said:
OK, when you are taking your gravity readings with your refractometer, are you correcting for alcohol content?  The  refractometers used for measuring sugar solutions do not account for the lower density of alcohol, so the reading must be corrected.  In the refractometer tool in BeerSmith, you can set the measurement type for "fermenting wort gravity'.  You will then need to enter the original gravity along with the refractometer reading in Brix.  BeerSmith will then calculate out the corrected gravity reading.

So, your present gravity reading of 1.032 would be 8.04 Brix.  When I enter 8.04 Brix as the present reading with an original gravity reading of 1.048, I see a corrected gravity reading of 1.022.  This is still only an apparent attenuation of around 54%.

Unless you mashed at a fairly high temperature, such as 160F or so, this is way too low for a German ale strain, which should be in the 73% to 77% range for attentuation.

So this gets back to what KellerBrauer suggested in that your yeast may have stalled out for whatever reason.  You can (1) try adding a bit of yeast nutrient to see if that will restart the yeast, (2) make a very small starter of that yeast or another strain and add that to see if it will complete the fermentation, or (3) start over again (not always a bad choice).
Click to expand...

Hi Oginme.  THanks very much for your post.  THe refractometer may well (is) be something I am misinterpreting / reading.  I measure 6 brix on my refractometer.  So checking BS app now, I have 6 brix entered with fermenting wort gravity as my setting.  With 1048 entered as the OG I see a revised corrected gravity of 1.009.  I am unsure of the meaning of OG of finished beer but will use BS help to check this when home.

So...not so bad maybe.  And also maybe I need to sometimes cross check to a hydrometer as reference in future.

Derek
 
Derek Toering said:
So checking BS app now, I have 6 brix entered with fermenting wort gravity as my setting.  With 1048 entered as the OG I see a revised corrected gravity of 1.009.  I am unsure of the meaning of OG of finished beer but will use BS help to check this when home.

So...not so bad maybe.  And also maybe I need to sometimes cross check to a hydrometer as reference in future.

Derek
Click to expand...

Derek,

The OG is your starting gravity.  This is needed for the calculation of the correction for the amount of alcohol in the fermenting wort.

Generally, I find good practice is to do my OG and FG (at bottling time) readings using my hydrometer. 

 
Thanks yes I understand what OG is just wasn't sure of the context of this is for the dropdown menu 'OG of finished beer'.

ON the whole...might not be as bad as i thought.  Time to get that hydrometer tube fixed...

Appreciate your input.

Derek
 
Ah, got it.  If you take the final gravity with both a refractometer and a hydrometer, you can back calculate the original OG of the beer.  I use this when I have a large addition of sugar(s) or fruit during fermentation. 
 
Ok that's a good tip.  I was thinking of doing a fruit beer next so that is some thing to implement.

I feed my spent grains to Pierre and Louis...sheep.
 
You must log in or register to reply here.
Back
Top