OG issues driving me crazy

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Fly_Guy

Fly_Guy

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In my past few batches I always seems to be a few points low when looking at my predicted gravity. Today, I was 9 points low. I had a predicted OG of 1.063 and ended up at 1.054. I can't figure out what else to do or try at this point. My recipe and methods are below. This was supposed to be a nice American IPA

3.5 gallons of RO water treated with 6.2g gypsum, 1.75g epsom salt, 0.70g canning salt, 0.30 calcium chloride, 0.75g chalk, and 0.50mL of 88% Lactic Acid.

Grain Bill:
2.5 lbs pale - ale malt (3.5L)
2.5 lbs Mutons Maris Otter (3.0L)
4.5 oz goldpils vienna malt (6.0L)
4.5 oz Caramel 40 (40L)

Predicted OG @ 68% Brew house efficiency was 1.063.

I heated up 3.5 gallons of treated water to 156.8, mashed in and hit a mash temp of 151.
At 15 minutes, heat dropped to 149, brought it back up to 151F and checked pH which was 5.3-5.4 (bouncing back and forth on my cheaper aperna)
By the end of the 60 minute mash, temp dropped down to about 147F, I brought that back up to 151F while I heated up 0.25 gallons of untreated water for a pour over sparge.
At 13 minutes, I added 8oz of water which had my yeast nutrient dissolved in it, and my whirlfloc tablet dissolved in it.

Brought this all to a boil
Added a total of 2oz of hops between the 53 minute mark and a 30 minute whirlpool which started around 130F.

Finished cooling, collected about 2.20 gallons of wort, with about 0.5 gallons left in the BK.

Measured OG with two different hydrometers at 60F and got a reading of 1.052 and 1.054
I did have 2 PBG readings of 1.042 and 1.044 with my refractometer but I know they aren't really as great as they sound for that.

So now my American IPA is like a super hopped up Session IPA (should end around 5.5% alcohol with 80 IBU's)

I ask the brew shop to double crush my grain, and I did not see any obvious whole kernels and all the bags had quite a bit of that powdery goodness.

Would not boiling off enough cause my gravity to be that low, I aim to get about 2.25 into the fermenter? Is the only other possibility grain crush? Should I give up and set my brewhouse efficiency incredibly low (like 60) moving forward and just buy more grain? I cannot for the life of me, figure out what I am doing wrong.

I use the free version of brewers friend to calculate my OG and IBU's for me. I use an Escali digital scale which I keep calibrated with a calibration weight and my pH meter I calibrated the night before brew day, lastly refractometer was checked and zeroed.

Any help, suggestions or critique's of my process would be greatly appreciated
 
Here is a picture of my grain. Maybe it is still too coarse?

20210715_151820.jpg
 
One explation is that you didn't boil off enough water to reach your target OG. Without accurate volume measurements, it's hard to know for certain. But if we assume 68% efficiency, we can estimate water volumes.
  • 5.5 lbs of grain at 68% efficiency is 135 gravity points (5.5 * 36 * 68%)
  • In 2 1/8 gal water, OG is 63 (135 / 2.125)
  • In 2 3/4 gal water, OG is 49 (135 / 2.75)
Again, assuming 68% efficiency, it looks like you ended up with around 2.7 gal wort at the end of the boil.
 
Hmm, maybe I need to relearn the points thing. I haven't read that chapter since I first read Palmers book a few years ago.

I ordered a stainless steel ruler so I can accurately measure out my water volumes
 
Fly_Guy said:
In my past few batches I always seems to be a few points low when looking at my predicted gravity. Today, I was 9 points low. I had a predicted OG of 1.063 and ended up at 1.054. I can't figure out what else to do or try at this point. My recipe and methods are below. This was supposed to be a nice American IPA

3.5 gallons of RO water treated with 6.2g gypsum, 1.75g epsom salt, 0.70g canning salt, 0.30 calcium chloride, 0.75g chalk, and 0.50mL of 88% Lactic Acid.
chalk doesn't dissolve well in the mash. If you need a higher pH you should use less lactic acid.

Grain Bill:
2.5 lbs pale - ale malt (3.5L)
2.5 lbs Mutons Maris Otter (3.0L)
4.5 oz goldpils vienna malt (6.0L)
4.5 oz Caramel 40 (40L)

Predicted OG @ 68% Brew house efficiency was 1.063.

I heated up 3.5 gallons of treated water to 156.8, mashed in and hit a mash temp of 151.
At 15 minutes, heat dropped to 149, brought it back up to 151F and checked pH which was 5.3-5.4 (bouncing back and forth on my cheaper aperna)
is this the pH of a cooled, room temp sample?

By the end of the 60 minute mash, temp dropped down to about 147F, I brought that back up to 151F while I heated up 0.25 gallons of untreated water for a pour over sparge.
At 13 minutes, I added 8oz of water which had my yeast nutrient dissolved in it, and my whirlfloc tablet dissolved in it.
why did you add yeast nutrient and Whirlfloc to the mash?

Brought this all to a boil
Added a total of 2oz of hops between the 53 minute mark and a 30 minute whirlpool which started around 130F.

Finished cooling, collected about 2.20 gallons of wort, with about 0.5 gallons left in the BK.

Measured OG with two different hydrometers at 60F and got a reading of 1.052 and 1.054
I did have 2 PBG readings of 1.042 and 1.044 with my refractometer but I know they aren't really as great as they sound for that.
so based on @BrewnWKopperKat calculations , your efficiency is better than 68%. You got basically 2.75 gallons of wort at the end of the boil, and had an OG of 1.053. If you had 68% efficiency, you'd be at 1.049.
Your Brewhouse efficiency is lower, but that's because you're leaving wort behind in the kettle, which is fine.
When planning batches, plan your gravity calculations off the volume in the kettle after the boil, and adjust kettle volumes to get what you want into the fermenter without trub.

So now my American IPA is like a super hopped up Session IPA (should end around 5.5% alcohol with 80 IBU's)

I ask the brew shop to double crush my grain, and I did not see any obvious whole kernels and all the bags had quite a bit of that powdery goodness.

Would not boiling off enough cause my gravity to be that low, I aim to get about 2.25 into the fermenter? Is the only other possibility grain crush? Should I give up and set my brewhouse efficiency incredibly low (like 60) moving forward and just buy more grain? I cannot for the life of me, figure out what I am doing wrong.

I use the free version of brewers friend to calculate my OG and IBU's for me. I use an Escali digital scale which I keep calibrated with a calibration weight and my pH meter I calibrated the night before brew day, lastly refractometer was checked and zeroed.

Any help, suggestions or critique's of my process would be greatly appreciated
Click to expand...
 
Depending on your batch size, remember that water does expand as it gets hotter and certainly when full of bubbles during boil the volume increases the most.
 
Fly_Guy said:
Like put in half a gallon, measure that height, then a gallon measure that height...etc.
That way during the boil I know exactly how much water I have in my boil kettle. Mine did not come with markings and I don't have any spare wire to etch my kettle
Click to expand...

Got ya, I was very confused their for a moment.
Fly_Guy said:
Like put in half a gallon, measure that height, then a gallon measure that height...etc.
That way during the boil I know exactly how much water I have in my boil kettle. Mine did not come with markings and I don't have any spare wire to etch my kettle
Click to expand...

Got ya, I was confused there for a minute!
 
Adjust your efficiency to 64% on your next batch and you’re set. If you’re consistently getting the same efficiency with the same process, well...you’re doing good.
 
DuncB said:
Well it's good consistency and room to improve efficiency.
Click to expand...


that's close to what iwas getting back in the beginning, before someone on the old morebeer forum gave me the tip to slow down my sparge....went straight from 62% using like 25lbs base malt for a 10 gallon batch to 83%, only needing like 18lbs. it's nice to have people to talk to!
 
1) Get your own mill and crush harder.
2) Sparge more, rinse out more sugars, boil harder, hit your volume, and don't throw away 0.5 gallon! Don't fear the cold break, just keep it.
 
Last edited:
Kickass said:
Adjust your efficiency to 64% on your next batch and you’re set.
Click to expand...
Perhaps.

Personally, I'd focus on measuring water/wort volumes more accurately so that I can more accurately calculate efficiency numbers.

eta: Also, back in #8, @marc1 had a good comment about the number of items involved in the water adjustments. FWIW, IMH, I would simplify the water adjustments before being too concerned about efficiency numbers.
 
Last edited:
Guessing it might be a combination of factors.
|When you said you had a half gallon left in the kettle, was that clear wort or trub? You (obviously|) want to leave as little clear stuff as possible, so you may not have boiled enough off (and that is a tough one until you really know your system and boil-off rates - myself, I keep tabs and |I'll increase the heat on my burner to increase it a bit if I think |I need to .
|Also it could be the crush isn't fine enough - you are doing BIAB, right? That does take a finer crush than traditionl mash.
 
It's not the cause of poor efficiency, but I noticed you added chalk (which doesn't dissolve properly anyway), and then added acid to neutralize the chalk you just added? Don't do that. In fact, don't use chalk at all unless you know how to bubble c02 through the water to dissolve it, and if you are using acid at all, keep the chalk a mile away. What was the mash pH?

And as was mentioned, when you throw away so much of your wort, and start with more water, your efficiency will suffer. Either accept that, or throw away less wort.
 
@marc1 I added the acid to lower the pH and added the chalk to keep all my ion's in balance (which is what bru'n water suggests to do. I added all my water adjustments the night before and stirred it up good with my spoon and a whisk and in the morning the water was about as clear as it has ever been.
My pH was measured at 74F, I know it should be a bit lower but I got distracted with the rest of the brewing process and forgot to check it again after the sample had cooled off a bit more in the fridge.
@marc1 I should have been more clear, I added the whirlflock and yeast nutrient with 13 minutes left in the boil, it was going to be 10 minutes but it looked like I had a bit too much water so I cranked up the heat and let it go for another 3 minutes...actually 8 in total but only 3 after those were added.

@dmtaylor I don't fear the cold break, I just like clear wort. The kit I got came with a siphon, funnel and a screen to put in the funnel. So at the end of the boil I always siphon my wort through the screen in the funnel, once it gets clogged with hops/trub I usually call it good. Sometimes I'll dump some in if I want a bit more volume or it looks like it won't take an hour for me to get the wort in while keeping all the hops out. Doing it this way might seem ridiculous, but I end up leaving very little trub in the fermentor when it is time to bottle.

@jrgtr42 yes this is BIAB, which I why I ask the brew shop to double crush the grain, but even with that I've been struggling to hit predicted OG.

I have an amber that I'm going to be brewing soon.
I'll take better water measurements, boil a bit harder, try to throw less wort away, do my pour-over sparge with more water and mash with a bit less water.

If all that STILL doesn't get me the OG I want, I might just have to buy a grain mill...or find someone who will let me use theirs to crush grain. If there are any adjustments I missed or anything else you can think of please let me know!
 
with the grain bill you have and the amount of water used, you're getting a conversion efficiency between 90% and 95% if the pre-boil gravity reading was between 1.042 and 1.044. Looks like total water was about 3.75 gallons?

therefore I'd say your crush is fine. You can do better (close to 100%) but 90-95 is fine.

so I'd say the boil off rate was off in the software calculations you have. Do you have a measurement for your pre-boil volume?
 
Fly_Guy said:
@marc1 I added the acid to lower the pH and added the chalk to keep all my ion's in balance (which is what bru'n water suggests to do. I added all my water adjustments the night before and stirred it up good with my spoon and a whisk and in the morning the water was about as clear as it has ever been.
My pH was measured at 74F, I know it should be a bit lower but I got distracted with the rest of the brewing process and forgot to check it again after the sample had cooled off a bit more in the fridge.

@marc1 I should have been more clear, I added the whirlflock and yeast nutrient with 13 minutes left in the boil, it was going to be 10 minutes but it looked like I had a bit too much water so I cranked up the heat and let it go for another 3 minutes...actually 8 in total but only 3 after those were added.

I have an amber that I'm going to be brewing soon.
I'll take better water measurements, boil a bit harder, try to throw less wort away, do my pour-over sparge with more water and mash with a bit less water.

If all that STILL doesn't get me the OG I want, I might just have to buy a grain mill...or find someone who will let me use theirs to crush grain. If there are any adjustments I missed or anything else you can think of please let me know!
Click to expand...

I don't think Bru'n water suggests adding chalk to "balance" ions - you may be misinterpreting something. The last version that I have of it is 1.25. Here's what it says:
Bru'n Water Instructions Tab said:
Acids and Bases (Baking Soda, Chalk, and Pickling Lime) should not both be added to water since they counteract each other. Add either an acid or a base as needed to control mash pH, not both. If both an acid and base are entered on the Water Adjustment sheet, warnings will be displayed on the Water Adjustment sheet (red cells) to alert the brewer of this error. This warning is also displayed if acid malt is included in the grain bill and a base is added to the mashing water.

The bicarbonate contributions shown for Baking Soda, Chalk, and Pickling Lime in the Water Additions area represent their equivalent bicarbonate alkalinity contributions. Baking Soda and Pickling Lime will easily dissolve in water or the mash. Since Chalk has limited solubility in water or in the mash, special measures will be required to dissolve the Chalk and produce its expected bicarbonate and alkalinity contribution. Adding Chalk powder directly to the mash has been proven to be ineffective in adding alkalinity to the mash.

To effectively use Chalk, the Chalk has to be fully dissolved by mixing it with water in a sealed container and then pressurizing with Carbon Dioxide (CO2). The CO2 dissolves the Chalk in the water, changing the water from cloudy to clear. This process is not quick and requires planning and preparation. Therefore, using Chalk to add alkalinity to mash water is not recommended unless the brewer is going to perform these measures.

If the Desired Water Profile has a significantly lower than desired bicarbonate (HCO3) concentration (Alkalinity), then a preferred method to add bicarbonate to mashing water is to add Pickling Lime or Baking Soda since Chalk is difficult to dissolve in water or the mash. When alkalinity needs to be added to the mash water, Pickling Lime or Baking Soda will provide more certain results. Care should be exercised when adding Baking Soda since the Sodium concentration should typically not exceed 100 ppm for good brewing results. ONLY MASHING WATER SHOULD HAVE ITS BICARBONATE CONCENTRATION INCREASED. SPARGING WATER NEVER NEEDS ADDED ALKALINITY.

A variety of minerals used for water chemistry adjustment are referenced in the spreadsheet. Vary the mineral amounts and compare the Target Water Adjustment and Actual Water Adjustment results to find the combination of minerals that best approximate the Desired Water Profile. When using Excel to run Bru'n Water, the Target and Actual adjustment cells will turn GREEN when the values are within 10 ppm of each other. You should not be too concerned with a difference greater than 10 ppm, but that is a reasonable target range. In general, you should use a lower than targeted concentration when they have difficulty in finding the correct combination of minerals to add to meet the targeted concentrations.
Click to expand...

The pH at that temp should be fine, if you used a calibrated meter.

If the measurements that you posted above are accurate, then you don't have much of a problem. You might be confusing mash/sparge efficiency with brewhouse efficiency in the software.

If you lost 0.5 gallons to trub, then that is 0.5 gallons/2.7 gallons = 18.5% loss of overall extract right there, meaning that the most you could get for brewhouse efficiency is theoretically 81.5%, but if say, you had a nice 80% mash/sparge efficiency, then you'd lose almost 20% more on top of that in brewhouse efficiency from the wort left behind. It's fine, and you can plan for a little more wort to account for that loss, or you can work at losing less to trub.
 
In my mind, the only efficiency to worry about is your preboil efficiency. What was your OG of a given volume of water, before your started the boil.

The rest is you are calculating losses due to evaporation, dead space, hop and trub absorption, etc. I believe that is called brewhouse efficiency.

I am not saying you should not account for these things. I am saying that you should not wrongly estimate those factors and then go chicken little and cry about your efficiency is falling.

If you calculated and allowed for .25 gallon loss dead space and .25 loss gallon for hops, but ended up with .50 gallon dead space and .50 gallon to hops, then your ferment volume will be .50 short. But the beer will be the same gravity, just less beer.

In that case try to get a handle on what your system losses are and anticipate and allow for them so you get the beer you were shooting for.
 
@jdudek I do not have an official pre-boil volume, just one that I can estimate. I began the BIAB with 3.50 gallons, poured over with another 0.25 gallons for a total water amount of 3.75. I tried to squeeze the bag to extract as much water as possible. Based on other's who have done the measurement (something I will try to do moving forward) I can assume I lost 0.07-0.08 gal/lb to grain absorption, which would bring my preboil volume down between 3.31-3.36 gallons.

In others' experiences, is brewer's friend usually pretty good about predicting OG? I know I was entering 3.75 gallons into the pre-boil volume instead of the corrected amount, but even when I switch that to 3.33 it does not change the predicted OG (at 68% brewhouse efficiency) and I entered 3.33 preboil, 2.75 post boil, with 2.25 hoping to get into the fermentor and the OG remains 1.063. Interestingly enough, when I change the target to boil kettle and enter 2.75, my OG drops to the 1.051 mark which is much closer to my measured OG.

I have no idea why entering the post-boil volume of 2.75 gallons, leaving 0.5 behind and getting 2.25 gallons to fermentor changes the OG. Any guesses on this? Am I over manipulating the software at this point or just using it wrong? The OG in the trub should be the same as the OG in the fermentor. Should I just use it like this?

I'll try a dunk sparge with the next brew as well now that I have access to my bigger pot again.
 
Fly_Guy said:
@jdudek I do not have an official pre-boil volume, just one that I can estimate. I began the BIAB with 3.50 gallons, poured over with another 0.25 gallons for a total water amount of 3.75. I tried to squeeze the bag to extract as much water as possible. Based on other's who have done the measurement (something I will try to do moving forward) I can assume I lost 0.07-0.08 gal/lb to grain absorption, which would bring my preboil volume down between 3.31-3.36 gallons.

In others' experiences, is brewer's friend usually pretty good about predicting OG? I know I was entering 3.75 gallons into the pre-boil volume instead of the corrected amount, but even when I switch that to 3.33 it does not change the predicted OG (at 68% brewhouse efficiency) and I entered 3.33 preboil, 2.75 post boil, with 2.25 hoping to get into the fermentor and the OG remains 1.063. Interestingly enough, when I change the target to boil kettle and enter 2.75, my OG drops to the 1.051 mark which is much closer to my measured OG.

I have no idea why entering the post-boil volume of 2.75 gallons, leaving 0.5 behind and getting 2.25 gallons to fermentor changes the OG. Any guesses on this? Am I over manipulating the software at this point or just using it wrong? The OG in the trub should be the same as the OG in the fermentor. Should I just use it like this?

I'll try a dunk sparge with the next brew as well now that I have access to my bigger pot again.
Click to expand...

The OG predictions of brewing software are based off of the parameters that you enter. Brewer's friend should give decent predictions if you put the correct info in for it to calculate.

Looking at Brewer's Friend, it comes down to basing things off of brewhouse efficiency for the fermenter volume, or kettle efficiency for kettle volume. Like I explained above, you're brewhouse efficiency takes a hit because of your smaller volumes and larger trub losses. Kettle efficiency seems more relevant to what you want to do.

I think it's easier to set things for kettle efficiency and then plan your volumes to account for trub losses to the fermenter. You have real data from a batch here - pick kettle efficiency and then change the % until it matches what you got. Keep track of it over the next several batches. You'll get a feel for what it is in your system, keeping in mind that the efficiency can change based on your grain bill, sparge volumes, etc.
 
Fly_Guy said:
@jdudek I do not have an official pre-boil volume, just one that I can estimate. I began the BIAB with 3.50 gallons, poured over with another 0.25 gallons for a total water amount of 3.75. I tried to squeeze the bag to extract as much water as possible. Based on other's who have done the measurement (something I will try to do moving forward) I can assume I lost 0.07-0.08 gal/lb to grain absorption, which would bring my preboil volume down between 3.31-3.36 gallons.

In others' experiences, is brewer's friend usually pretty good about predicting OG? I know I was entering 3.75 gallons into the pre-boil volume instead of the corrected amount, but even when I switch that to 3.33 it does not change the predicted OG (at 68% brewhouse efficiency) and I entered 3.33 preboil, 2.75 post boil, with 2.25 hoping to get into the fermentor and the OG remains 1.063. Interestingly enough, when I change the target to boil kettle and enter 2.75, my OG drops to the 1.051 mark which is much closer to my measured OG.

I have no idea why entering the post-boil volume of 2.75 gallons, leaving 0.5 behind and getting 2.25 gallons to fermentor changes the OG. Any guesses on this? Am I over manipulating the software at this point or just using it wrong? The OG in the trub should be the same as the OG in the fermentor. Should I just use it like this?

I'll try a dunk sparge with the next brew as well now that I have access to my bigger pot again.
Click to expand...
as others have mentioned, I would definitely use kettle and not fermentor as the target. the quantity of beer left behind in your kettle does not change anything in terms of the beer itself (only the amount). Brewhouse efficiency is annoying in my opinion and confuses things. Mash efficiency is a far more useful metric. I don't use brewer's friend but I punched in your fermentables and volumes and get pretty much the OG you measured at a 70% mash efficiency.
1627313942752.png


It's wonky that pre-boil volume does not make a difference in OG, but that's probably because BF has you entering your mash efficiency which essentially already accounts for all these numbers. What should really happen is that efficiency should change based on the amount of pre boil volume. More volume (better squeeze, or sparge), more efficient. Since the efficiency is entered as a hard number, then you can enter any odd number for pre boil volume and BF is happy. It's what most brewing software does, not optimal in my opinion. A predictive model is a lot less frustrating :)
 
Thank you so much for that insight!

Thinking back it definitely is confusing. I brewed a previous batch of the infamous cream of three crops ale, brewers friend listed the og as like 6 points higher, but I had hit exactly what that recipe predicted for OG and that was when my confusion really started. Then this IPA sent me over the top.

The extra surprise is when I do the kettle efficiency, my IBUs ended back at the 60ish mark so it might be far more balanced than I thought it would be after that brew day.
 

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