ABV lower than normal - Advice

[crazymoyo]

Hello fellas, I hope you are doing great!

Am new to homebewtalk and am looking to some advice to what am doing wrong
I brewing for the last year mostly Pale Ales and IPA, also tried once Neipa.

Am facing an issue where my beers turn out having low abs, approx 2.5-3.5% where they supposed to be around 5.5-6.5%. I found couple of recipes I liked and I experiment with them since I believe homebrewing it's all about experimenting and producing great beer

Brewing Sofrware: Brewfather
My brewing equipment: Brewmonk 30L
Batch size: 28L

Fermentable 7.2Kg
3.2Kg Pale Ale (Ireks)
2.5lg Pilsner (Ireks)
500g Vienna (Weyermann)
40g Carapils (Weyermann)
40g Carared (Weyermann)
200g Caramunich I (Weyermann)

Hops 225g
25g Amarillo 60 Mins / Boil
15g El Dorado 30 Mins / Boil
15g El Dorado 15 Mins / Boil
10g El Dorado 5 Mins / Boil
60g Mosaic 30 Mins / Hopstand @ 80c
65g Amarillo Day 7 - Dry Hop
35g El Dorado Day 7 - Dry Hop

Misc
3g Calsium Chloride / Mash
4.5g Gyprusm / Mash
1 Protafloc / 15 mins / Boil

Yeast
2 x Fermentis US-05 (22g)
Ferment for 14 days @ 20c

Mashing Profile
60mins @ 65c
10mins @ 75c Mash out

Water
25.18L Mash water
15.53L Sparge water


Brewfather calculates the the beer should have a:
Estimated Final Gravity:1.011
Apparent Attenuation: 79.9%
Alcohol by volume: 6%

My actual reading are below:

PreBoil Gravity: 16.7Brix
Specific Gravity: 1.0685
Potential Alcohol By Volume: 9.3%

Original Gravity: 12.2Brix
Specific Gravity: 1.0492
Potential Alcohol By Volume: 6.5%

Final Gravity: 7.2
Specific Gravity: 1.0285
Potential Alcohol By Volume: 2.72%

As you can see 2.72 is nowhere near 6%
Am using a Brix refractometer.

Am I doing something really wrong here? Do I need more grains or should I mash for more time?

Looking forward to your thoughts
Thanks in advance

 

[Pkrd]

Welcome to HBT.

Refractometers aren't good for measuring FG because you need to correct for the alcohol present. Get a hydrometer.

Also your preboil gravity can't be higher than your OG, boiling concentrates the wort.

 

[crazymoyo]

Thank you Pkrd I will order one, I feel it though that the alcohol is missing from my beer

 

[crazymoyo]

Other than that do u find anything wrong with my recipe or something to improve to be more efficient? Just a quick not is that the Preboil Gravity I took it before sparging

 

[Jag75]

Hows your crush ? If its not milled good enough your efficiency suffers.

 

[day_trippr]

First, it's not as bad as suspected. Using a refractometer with fermenting beer without correction for the presence of alcohol will result in increasingly erroneous Specific Gravity readings as the beer ferments.

Using the numbers provided with Beersmith3's refract tool shows:

• The OG of the pitched wort was 12.2 Brix/1.048 SG
• The final gravity of the fermented wort was 7.2 Brix/1.016 SG
• The resulting ABV is 4.2%

I did not try to calculate the recipe's expected pre-boil SG. To understand if there are any process issues extant we would need to know that, as well as what the actual volume into the fermentor was...

Cheers! (enjoy your session beer! )

 

[Kickass]

feel it though that the alcohol is missing from my beer

The power of suggestion is often an insurmountable hurdle. Lie to someone and tell them the FG of your 1.008 beer is 1.025 and they’ll tell you it’s too sweet. Lie to someone and tell them that a 4% ABV beer is 8% and they’ll say they feel drunk.

 

[Garrett Allen]

Other than that do u find anything wrong with my recipe or something to improve to be more efficient? Just a quick not is that the Preboil Gravity I took it before sparging

Preboil should be taken after all water has been added in your process. So if you're sparging, you should take preboil right before the boil and after sparging. Getting data for the amount of sugars you got just in the mash is great, but that is not the definition of preboil gravity.

Your recipe looks fine. From your numbers and using a refractometer calculator (hard to have really accurate numbers because I don't know your wort correction factor), it seems like your %ABV is probably close to 4.5.

You can use a refractometer, but it takes some data collection and calculation to be accurate. I agree a hydrometer is more accurate (assuming you degas your samples).

 

[simplepleasuresbrwery]

I have been brewing for 4 years now and in last year or so started using Milwaukee refractometer - once you have your wort correction factor and tools such as refractometer calculator from Brewers Friend they can be very useful. Measuring small samples as you boil - quickly at the end of the boil and see how far your are off your expected OG. I suspect a lot of your issues may be dialing in your equipment with parameters such as evaporation rate per hour etc. If you are over your end boil volume you will miss your target OG. So take a quick refractometer reading and see if you are off - if you are boil for another 9 minutes this will raise your gravity by a point alternatively turn your kettle off- cool and put in your fermenter. Measure the volume and OG - if you are off add sugar dissolved in boiling water (there are a lot of calculators online). Alternatively if you are too high - make a stronger beer or add water (again calculators online)

 

[RM-MN]

My actual reading are below:

PreBoil Gravity: 16.7Brix
Specific Gravity: 1.0685
Potential Alcohol By Volume: 9.3%

Original Gravity: 12.2Brix
Specific Gravity: 1.0492
Potential Alcohol By Volume: 6.5%

Final Gravity: 7.2
Specific Gravity: 1.0285
Potential Alcohol By Volume: 2.72%

Something is off between these two measurements. If you have a preboil of 1.065 and you boil off some liquid you are concentrating the solution, not diluting it. I suspect the your original gravity measurement is in error. If you only took the preboil reading and the final gravity reading your alcohol content would be about 5.4% ABV.

 

[Jag75]

I think the confusion is the pre boil gravity check . The op checked before sparging .

 

[crazymoyo]

Hows your crush ? If its not milled good enough your efficiency suffers.

I believe my crush is decent but it's a thing I will change to around 2mm

 

[crazymoyo]

First, it's not as bad as suspected. Using a refractometer with fermenting beer without correction for the presence of alcohol will result in increasingly erroneous Specific Gravity readings as the beer ferments.

Using the numbers provided with Beersmith3's refract tool shows:

• The OG of the pitched wort was 12.2 Brix/1.048 SG
• The final gravity of the fermented wort was 7.2 Brix/1.016 SG
• The resulting ABV is 4.2%

I did not try to calculate the recipe's expected pre-boil SG. To understand if there are any process issues extant we would need to know that, as well as what the actual volume into the fermentor was...

Cheers! (enjoy your session beer! )

I was with the impression that the refractometer is the most accurate compared to hydrometer that's why I bought one Regarding the fermenter volume is 29-30L, pre boil amount is around 37L+

Should I consider any digital monitoring like iSpindel?

 

[crazymoyo]

The power of suggestion is often an insurmountable hurdle. Lie to someone and tell them the FG of your 1.008 beer is 1.025 and they’ll tell you it’s too sweet. Lie to someone and tell them that a 4% ABV beer is 8% and they’ll say they feel drunk.

For sure that's 100% truth!

 

[IslandLizard]

I believe my crush is decent but it's a thing I will change to around 2mm

2mm??? That's way, way too wide!

2mm = 0.079" for us, non-metric ones. What gap were you using for the batch above?

We typically mill Barley around 0.034" (0.86 mm), a bit tighter, 0.025" (0.64 mm) for wheat, rye, and other small kernels of that size. Sometimes even finer for BIAB as the fine mesh of the bag is the lauter filter.

 

[crazymoyo]

Preboil should be taken after all water has been added in your process. So if you're sparging, you should take preboil right before the boil and after sparging. Getting data for the amount of sugars you got just in the mash is great, but that is not the definition of preboil gravity.

Your recipe looks fine. From your numbers and using a refractometer calculator (hard to have really accurate numbers because I don't know your wort correction factor), it seems like your %ABV is probably close to 4.5.

You can use a refractometer, but it takes some data collection and calculation to be accurate. I agree a hydrometer is more accurate (assuming you degas your samples).

I will get a hydrometer to have control and accurate results. To be on the safe side I was also thinking to add more grams to my grain bill to have more sugars available for the yeast. To have a 6% ABV with 7.2kg grains in 30L fermenter volume is balanced?

 

[crazymoyo]

2mm??? That's way, way too wide!

2mm = 0.079" for us, non-metric ones. What gap were you using for the batch above?

We typically mill Barley around 0.034" (0.86 mm), a bit tighter, 0.025" (0.64 mm) for wheat, rye, and other small kernels of that size. Sometimes even finer for BIAB as the fine mesh of the bag is the lauter filter.

Oh NO, I have to check the exact number but for sure it was around 3mm, I was afraid to mill lower because of the circulation during mashing

I will get a picture of the mill and the measuring scale once am back home

 

[IslandLizard]

I have to check the exact number but for sure it was around 3mm,

3mm, ouch! Take a look at your grist when milled that wide, it will be barely crushed, and very coarse, may even contain uncrushed kernels. That's not helping your mash efficiency, your wort's gravity, and your ABV in the end.

For an easy visual/gauge, a regular credit card is around 0.034" (0.86 mm) thick. On a 2-roller mill that should give you a very decent crush on barley, but a bit too wide for wheat and rye. When the mash is recirculated (not just stirred) you may want to crush a tad coarser (say, 30% wider) for better permeability.

 

[Nagorg]

@crazymoyo I echo everything that's been said by these folks. Other than the gap on your mill and the likely resulting poor crush and low mash efficiency, everything else seems in order.

I use a refractometer too but after fermentation starts you have to use a calculator to compensate for the alcohol in the beer. And the reliability of the calculated SG declines with more alcohol present. They are great for monitoring the fermentation though since it only takes a few drops to measure progress. When the brix reading stops falling for a couple of days, the beer is typically done.

I do think that you can get away with a refractometer/calculator combo for lower gravity beers such as what you have been brewing. But when you start getting in the ~10% ABV range, I've found this to be less reliable. There's no dispute that a hydrometer provides the most reliable FG measurement.

On calculators, there are several free ones out there if you don't have BeerSmith. Below are a couple that I use.

OneBeer.net - Onebeer.net :: Homebrew :: Refractometer Calculator
Brewers Friend - Refractometer Calculator - Brewer's Friend

 

[eric19312]

A final gravity hydrometer is a nice option to use in combination with a refractometer. Use the refractometer for brew day measurements up to and including OG. Then continue to use the refractometer with a correction calculator during fermentation (or a Tilt hydrometer), and finally the FG hydrometer when you package. The FG hydrometer only works once the beer is below 1.020 but is super precise. Also super fragile so good to have a standard brewers hydrometer available as a backup.

https://www.morebeer.com/products/f...ork out of,-range, highly accurate hydrometer.

 

[dmtaylor]

This is largely a refractometer conversion problem. Whenever alcohol is present, you need to use the following calculator or equivalent to get accurate results. This one uses the Novotny equation which is the most accurate within 0.001 of a hydrometer if you do it right.

https://www.brewersfriend.com/refractometer-calculator/
And to take a jump deeper into the rabbit hole, see my standard guidance on how to properly use a refractometer for FG:

https://www.homebrewersassociation.org/forum/index.php?topic=28544.msg404366#msg404366
In this case, looks like you've got 4.4% ABV.

Other than that.... 7.2 kg malt just isn't enough for a higher gravity for a 28 liter batch. Low on malt. Some settings might be screwed up in your recipe software.

 

[Nagorg]

This is largely a refractometer conversion problem. Whenever alcohol is present, you need to use the following calculator or equivalent to get accurate results. This one uses the Novotny equation which is the most accurate within 0.001 of a hydrometer if you do it right.

In the not so far away past I'd have agreed with you on this. But my most recent high gravity fermentation changed my opinion.

What happened to me is that the brix readings continued to drop. Slowly but steadily. It got to the point where the attenuation was higher than the yeast performance spec and it kept going. I started wondering if I had a bug in my beer so I decided to spot check with my hydrometer. Upon doing that, I found that the FG was higher that the converted brix readings and actually landed my beer right where it should have been at max attenuation.

 

[dmtaylor]

In the not so far away past I'd have agreed with you on this. But my most recent high gravity fermentation changed my opinion.

What happened to me is that the brix readings continued to drop. Slowly but steadily. It got to the point where the attenuation was higher that the yeast performance and it kept going. I started wondering if I had a bug in my beer so I decided to spot check with my hydrometer. Upon doing that, I found that the FG was higher that the converted brix readings and actually landed my beer right where it should have been at max attenuation.

Great observation. Indeed, the refractometer becomes less and less accurate when OG is greater than about 1.080. In those cases you are better off relying on a good old hydrometer.

Cheers.

 

[crazymoyo]

Attaching images from my mill

 

[crazymoyo]

I will brew the same

This is largely a refractometer conversion problem. Whenever alcohol is present, you need to use the following calculator or equivalent to get accurate results. This one uses the Novotny equation which is the most accurate within 0.001 of a hydrometer if you do it right.

https://www.brewersfriend.com/refractometer-calculator/
And to take a jump deeper into the rabbit hole, see my standard guidance on how to properly use a refractometer for FG:

https://www.homebrewersassociation.org/forum/index.php?topic=28544.msg404366#msg404366
In this case, looks like you've got 4.4% ABV.

View attachment 717500

Other than that.... 7.2 kg malt just isn't enough for a higher gravity for a 28 liter batch. Low on malt. Some settings might be screwed up in your recipe software.

I used 7.2kg because Brewfather calculated the abv level, how much more g’s should I add to be on the safe side?

 

[dmtaylor]

Another kg would get you close, or maybe if in doubt 1.2kg.