Author Topic: Why is my OG lower than the projected OG of my recipe?  (Read 358 times)

Offline alekmager

  • 1st Kit
  • *
  • Posts: 15
    • View Profile
Why is my OG lower than the projected OG of my recipe?
« on: June 29, 2018, 10:23:17 PM »
I was following a recipe and the target OG was 1.065 but when we finished our OG was 1.044. Could this be from an incomplete extraction of the sugars in the mash itself? Could water chemistry play a roll in this? Should I increase mash time/temperature? Is there any advice on proper mash methods? We also did a BIAB FOR A 5 gallon used 10 lbs pale malt, 1 lb flaked oat, one lb flaked wheat, and 12 oz Carapils, with addition 12 oz turbinado sugar at 60 mins. Thanks any help is much appreciated.

Offline BrewBama

  • Senior Brewmaster
  • ******
  • Posts: 1491
    • View Profile
Why is my OG lower than the projected OG of my recipe?
« Reply #1 on: June 29, 2018, 10:45:13 PM »
Yes you did not extract all the sugar. Raising your time/temp depends on what temp you were mashing. Yes water pH could have contributed.

I recommend search online and reading ‘How to Brew’ by John Palmer.


Sent from my iPad using Tapatalk
Huntsville AL

Offline coolman26

  • Brewmaster
  • *****
  • Posts: 780
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #2 on: June 30, 2018, 01:28:06 AM »
I think you should 1st, download some software. I use Beersmith, but there are many. When you have this you can input your efficiency. You then know how much grain you need for YOUR system. There are many factors that can cause this. My guess is that being BIAB, you didn’t crush fine enough. Most modern Malts convert in less than the 60 min. Water/mash ph can play a roll. Also download Brew’n water and it will help you with this. There are so many perimeters that can cause low efficiency. I do not do BIAB, but my first batch was 51%. Chalk it up to a session beer. Lesson learned and make better beer the next time. I would crush fine, mash say 90 min, and make sure you take detailed notes. Make sure your boil vigor isn’t too intense too. That should get you started, happy Brewing.


Sent from my iPhone using Tapatalk
Jeff B

Offline oginme

  • Cellarman
  • **
  • Posts: 93
    • View Profile
    • My Farm
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #3 on: June 30, 2018, 02:31:25 AM »
The other aspect of this is volume.  Without the correlating volume readings, the gravity measurements alone will not tell you much.  If you were grossly over target for volume, this could be one reason the gravity was so low.  Likewise, if you did not boil off as much volume as the recipe was designed for your gravity would be low.

Offline soymateofeo

  • Cellarman
  • **
  • Posts: 36
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #4 on: June 30, 2018, 05:40:03 AM »
amigo!  This happens a lot.  I have a black belt in missing my target og. There are a few things you can do when this happens:

1. have some water on hand to dilute if you are over.  I think Denny is a big fan of this. (Denny?) I've done it a few times but my biggest problem is coming up short a few points. 

2. Keep some DME on hand to raise that gravity if you miss it. There's no foul in doing that.

But there are a plethora of ways to increase your efficiency.  I know that crush size has an impact.  Mashing out seems to have increased my efficiency. You can just calculate your recipes with the efficiency you get and make up the difference with grain.  It's a few bucks and it's probably the easiest solution. I used to batch sparge regularly and got around 78-82% efficiency but have since switched to no sparge and get around 68%.  Beersmith handles the calculations for me just fine.  IMO Efficiency is not an indicator of beer quality within acceptable levels.
Keep on brewing!

Offline Bob357

  • Assistant Brewer
  • ***
  • Posts: 241
  • I can't hang with Denny. My day ends at 1.060.
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #5 on: June 30, 2018, 11:31:00 PM »
The same recipe brewed using different equipment and/or procedures will almost always produce different results. Spend a few bucks on some decent brewing software and you'll have the ability to tailor recipes to work on your setup.


Beersmith and Brewers Friend are probably the 2 most popular, so likely the best choices. You could easily spend as much on ingredients for a batch of beer as either would cost you for a year.

Beer is my bucket list,

Bob357
Fallon, NV

Offline Joe Sr.

  • Official Poobah of No Life.
  • *
  • Posts: 4352
  • Chicago - NORTH SIDE
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #6 on: July 01, 2018, 03:06:29 AM »
The same recipe brewed using different equipment and/or procedures will almost always produce different results. Spend a few bucks on some decent brewing software and you'll have the ability to tailor recipes to work on your setup.


Beersmith and Brewers Friend are probably the 2 most popular, so likely the best choices. You could easily spend as much on ingredients for a batch of beer as either would cost you for a year.

Software will help  but first you need to know the efficiency of your system.

Track it for a few brews and then you can dial it in. Software alone I not the answer. Repeatable efficiency on your system and using software to tailor recipes will give you the results you're looking for.
It's all in the reflexes. - Jack Burton

Offline Robert

  • Senior Brewmaster
  • ******
  • Posts: 1665
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #7 on: July 01, 2018, 11:22:42 AM »
It looks like the recipe was assuming ~65% efficiency, which is pretty crappy but many people will put up with it.  The OP only got about 2/3 of that. (That grain bill, for 5 gal with normal efficiency in a conventional sparge, would deliver an OG around 1.100.)  So dialing in software is not the first agenda item.  Something is fundamentally wrong with the process.  +1 on the book learning.
Rob
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline KellerBrauer

  • Cellarman
  • **
  • Posts: 71
  • Bottoms Up!
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #8 on: July 01, 2018, 12:14:12 PM »
Greetings alekmager - I just plugged your fermentables into BeerSmith and used an equipment profile of 73% and I came up with an OG of 1.071.  So, somehow you estimated an OG of 1.065.  That’s would put the brewhouse efficiency at about 65%.  So, I’m wondering how you derived that number.  Are you using a brewing software?  Describe your equipment.

As I played with the numbers I found the grain bill without the turbinado sugar was very close to your projected 1.065 so I’m wondering if your projection included the sugar.  In any case, there are - as the other brewers pointed out - a number of reasons why we miss our target.  So, perhaps you can offer more information and we can help you further.
« Last Edit: July 01, 2018, 12:17:48 PM by KellerBrauer »
All good things come to those who show patients and perseverance while maintaining a positive and progressive attitude. :-)

Offline joelv

  • Cellarman
  • **
  • Posts: 35
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #9 on: July 01, 2018, 02:40:11 PM »
There are often times likely and less-likely culprits for questions like these.

Likely
Grain crush - I think with BIAB, you can get away with much finer crush without worry of a stuck sparge.

Mash Temp - out of whack thermometers could be an issue if the temp was too low. Especially if the mash was shorter in length of time.

Less likely
Length of mash. (Unless it was ridiculously low like 15 minutes). Conversion is pretty high in 30 mins and an hour is definitely enough to insure a normal conversion - assuming temps are 145f - 160f

Mash PH - while not optimal to be too far out of range, it is less likely to make this big of a difference and mash PH kind of likes to be close to normal all by itself (meaning most normal drinking water and grain combinations tend to be in a range that isn’t obscenely off target).





Sent from my iPhone using Tapatalk

Offline goose

  • 1st Kit
  • *
  • Posts: 21
    • View Profile
Re: Why is my OG lower than the projected OG of my recipe?
« Reply #10 on: July 06, 2018, 02:20:06 PM »
This is a bit long winded so I apologize in advance.

This happens from time to time for me as well.  Mostly missing the gravity is because of several possibilities.

1) Setting your brewhouse efficiency to high.  I use 80% for my calculations in BeerSmith for my darker beers and 85% for my lighter beers.  My light ales are usually right on or within 1-2% of the target OG.  My darker ones usually are in the 77-80% range or so.  I shoot for no more than 3-4% error and if I am less than that I do my happy dance.

2) As mentioned by others, if you volume is off, your OG will be off.  I always look at the sight glass on my boil kettle before I start chilling (about 5 minutes after EOB to let the wort settle down a bit) and adjust the OG calculations for what I see.  Remember to correct the volume for cooling shrinkage (4%) to get the correct volume for OG measurement.  If you are making 10 gallons, you should see about 10.4 gallons of hot wort in the kettle.  Also, if you pitch your yeast before taking an OG measurement, you need to include the volume of the starter as a part of your overall volume.  I always take my measurements pre-pitch.

3) Old grain or grain that yields poor extraction.  Grain that starts to go slack will not give you the sugars you are looking for.  We used to run into extraction efficiency problems from time to time when I did my professional brewing gig.  Although the malting process is well controlled, we sometimes did not get the yield we were looking for from certain lot numbers and had to adjust.

4) Not extracting all of the sugars mentioned by others.  Doing a mashout at 168 degrees will make the sugars more soluble and easier to run off.


I was following a recipe and the target OG was 1.065 but when we finished our OG was 1.044. Could this be from an incomplete extraction of the sugars in the mash itself? Could water chemistry play a roll in this? Should I increase mash time/temperature? Is there any advice on proper mash methods? We also did a BIAB FOR A 5 gallon used 10 lbs pale malt, 1 lb flaked oat, one lb flaked wheat, and 12 oz Carapils, with addition 12 oz turbinado sugar at 60 mins. Thanks any help is much appreciated.
Goose Steingass
Wooster, OH
Society of Akron Area Zymurgists (SAAZ)
Wayne County Brew Club
Mansfield Brew Club
BJCP Certified
AHA Governing Committee Member