Looking for help identifying why FG is 10 points high

[Murphyslaw11]

Hi all. I have a Marzen with a FG 10+ points higher than it should be. I am trying to determine if my mash process created too many unfermentable sugars before I assume it is a stuck fermentation. I brew on a Robobrew and use Brewfather, and I fermented in a corny keg under pressure at 12 psi. Thanks for any help.

Grain Bill:
6 lbs Weyermann Munich I
4 lbs Weyermann Pilsner
1 lb Weyermann Caramunich I
1 lb Weyermann Vienna

Water:
Mash 5.5 gallons distilled water - added 3g CaCl2, 1g epsom, 3g gypsom
Sparge 2 gallons distilled water - added 0.7g CaCl2, 0.23g epsom, 0.7g gypsum

Mash steps:
-Protein Rest: 131F for 15 min (immediately after mash-in, decocted 6 qt thick mash)
-Heated decoction to 152F for 10 min Sacch rest
(pH of main mash tested: 5.2 at 71F)
-Beta Rest: 146F for 45 min (used Robobrew to raise temp) (Boiled decoction for 30 min during this step)
-Alpha Rest: 158F for 30 min (added back decoction to raise temp from Beta rest. 8 degrees short. Used Robobrew to raise it) (immediately decoct 6 qt for second decoction)
-Boiled decoction for 15 minutes, then had to clear stuck mash in Robobrew. I drained the wort, stirred and added rice hulls to the mash, the added all back into the Robobrew.
-Mashout: 170 F for 10 minutes. (Added decoction back to main mash to reach 170F but due to stuck mash, wort and grains cooled. Mash temp was at 155 after adding the decoction. Used Robobrew to raise to mashout temp).

Pre-sparge: 4 gallons at 1.062

Sparge:
-Initial runoff was extremely slow due to the mash becoming stuck again
-Raised sparge water to 178F.
-Added 1 lb rice hulls as soon as runoff was completed. No sparge issues.

Pre-boil: 6 gallons at 1.053
90 minute boil
0.7 oz Tettnang & 0.53 oz Perle @ 60 min
7.5 tsp yeast nutrient & whirlflock @ 10 min

OG 1.063 (right on target)

Chilled to 52F
Transferred to corny keg (w/floating dip tube) via splashing. Shook keg to further dissolve oxygen.
Pitched 2L starter of Wyeast 2633 Oktoberfest Blend.
Added spunding valve set to 12 psi
Fermented at room temperature (69F)

Fast fermentation. Spunding no longer hisses 1 week later, but FG is 1.024.

 

[Deric]

How are you measuring FG?

 

[hotbeer]

Your Vienna and Caramunich might be too much together. I don't particularly know that they are, but when I see that increasing the body of a beer is part of a malts description, then I expect I'll probably have more unfermentable sugars from that malt.

I'm not entirely sure what your complicated mash was supposed to do for these modern improved malts. At best too little gain for so much effort. At worst, to much risk of doing something wrong or having a temp excursion that bites you. But IMO only on that.

 

[Bobby_M]

That wort should be very fermentable, except perhaps some dextrines created in the decoction. The question about how you measured the FG is pretty important and has not been answered. If it's a refractometer, your reading is inaccurate. The only other thing I can think of is that 12 psi is pretty damn high to spund so early.

 

[mashdar]

1. Per others, how are you measuring gravity? Tilt and refractometer are not accurate. Tilt cannot be adjusted. Refractometer can be adjusted, but to do it right is complicated. Depends how accurate you want to be.
2. Was 2L starter stir plate or some other method?
3. Did room temperature vary at all? Cold at night? etc
4. That's a bunch of crystal, but not a 1.024 bunch. More than I'd recommend for a marzen, though. Most recipes I'm familiar with are ~4-12oz for 5 gallons.
5. edit: Have you tested your hydrometer calibration in water?

 

[Murphyslaw11]

How are you measuring FG?

Hydrometer. The same one I measured og with

 

[Murphyslaw11]

Your Vienna and Caramunich might be too much together. I don't particularly know that they are, but when I see that increasing the body of a beer is part of a malts description, then I expect I'll probably have more unfermentable sugars from that malt.

I'm not entirely sure what your complicated mash was supposed to do for these modern improved malts. At best too little gain for so much effort. At worst, to much risk of doing something wrong or having a temp excursion that bites you. But IMO only on that.

Thanks for the input. The complicated mash was mainly to get a little more melanoidin character. I found that the melanoidin malt available near me gives a bit of a grainy flavor instead of just the sweetness. Aside from that, I just wanted to try decoction mashing for the first time. Probably backfired
Edit: also much of the complication occurred because the mash became stuck twice probably due to too fine of a grain crush. If the temp dropped, could it have caused too high of a FG?

 

[Murphyslaw11]

That wort should be very fermentable, except perhaps some dextrines created in the decoction. The question about how you measured the FG is pretty important and has not been answered. If it's a refractometer, your reading is inaccurate. The only other thing I can think of is that 12 psi is pretty damn high to spund so early.

Thanks for the reply. I measured with a hydrometer. I also tasted the beer and it was very sweet, so I believe the reading. I’ll check the hydrometer’s reading in water like others have suggested though. My worry about spunding any later is that I didn’t want off flavors from fermenting lager yeast at room temp. When would you have recommended to spund?

 

[Murphyslaw11]

1. Per others, how are you measuring gravity? Tilt and refractometer are not accurate. Tilt cannot be adjusted. Refractometer can be adjusted, but to do it right is complicated. Depends how accurate you want to be.
2. Was 2L starter stir plate or some other method?
3. Did room temperature vary at all? Cold at night? etc
4. That's a bunch of crystal, but not a 1.024 bunch. More than I'd recommend for a marzen, though. Most recipes I'm familiar with are ~4-12oz for 5 gallons.
5. edit: Have you tested your hydrometer calibration in water?

Thanks for the response.
1. Hydrometer
2. Stir plate. Do you think it may just not be enough yeast? I swirled the keg to see if it was just a stuck fermentation but there was no more hissing from the spunding valve.
3. No more variance than 1.5 degrees F.
4. I agree. I tend to really like the maltier versions, like Sam Adams and Hacker Pschorr, so I figured I’d increase a little.
5. I did per your recommendation. It measured 1.000

 

[mashdar]

Hmm. That's a stumper. Questions #2 and #3 were focused on a stalled fermentation, but 2L stir plate at 69F/12psi should be OK, I would think.

I think you've established that your readings are accurate.

My best guess is something in the mash process killed too many enzymes. How confident are you that thermometers are accurate? And you used a thick pull for the decoction? (mostly grain, leave most liquid behind)

edit: I also don't know how that yeast handles pressure.

 

[Bobby_M]

2. Stir plate. Do you think it may just not be enough yeast? I swirled the keg to see if it was just a stuck fermentation but there was no more hissing from the spunding valve.

All data considered so far, I think yeast pitch is the most likely issue. You made a 2L starter, but the actual pitched cells hinge a lot on the age of the pack of yeast you made the starter with. Wyeast is still starting with 100B cells at packaging and that degrades downward pretty quickly.

Now, considering a pressure ferment, which is more stressful to the yeast, I would pitch it like it were a high gravity lager; something like 30M cells/1mL or what BrewFather would called "Lager over 1.060". I was conservative with the yeast pack age at 2 months but even so, it calls for a 3.7 starter with at least 2 packs of yeast going in. If the pack was 4 months old, it's off the charts. The cell count in the pack is so low, you'd need to build the starter with like 6 packs to avoid a low inoculation rate.

 

[Murphyslaw11]

Hmm. That's a stumper. Questions #2 and #3 were focused on a stalled fermentation, but 2L stir plate at 69F/12psi should be OK, I would think.

I think you've established that your readings are accurate.

My best guess is something in the mash process killed too many enzymes. How confident are you that thermometers are accurate? And you used a thick pull for the decoction? (mostly grain, leave most liquid behind)

edit: I also don't know how that yeast handles pressure.

My RoboBrew temp prob I seems to be 5-10 degrees off, but since I knew that I also used a temp gun which I’m sure is accurate to make sure my temps were correct. The only place where I the temp may have dropped was when I had to drain the RoboBrew to clear a stuck mash. If the temp raises to the correct temperature, then falls 10-15 degrees, can this make wort less fermentable?

Fair point about the yeast. This could be it. I just bought another pack of the same yeast. I’ll pitch it tonight and see if it does the trick

 

[Murphyslaw11]

All data considered so far, I think yeast pitch is the most likely issue. You made a 2L starter, but the actual pitched cells hinge a lot on the age of the pack of yeast you made the starter with. Wyeast is still starting with 100B cells at packaging and that degrades downward pretty quickly.

Now, considering a pressure ferment, which is more stressful to the yeast, I would pitch it like it were a high gravity lager; something like 30M cells/1mL or what BrewFather would called "Lager over 1.060". I was conservative with the yeast pack age at 2 months but even so, it calls for a 3.7 starter with at least 2 packs of yeast going in. If the pack was 4 months old, it's off the charts. The cell count in the pack is so low, you'd need to build the starter with like 6 packs to avoid a low inoculation rate.

I appreciate the insight. I thought I’d be good with the starter going for 24+ hours but I never stepped it up from there. I just bought another pack of 2633 to see if that can finish the beer. Do you think I should build it up or just pitch the smack pack?

 

[day_trippr]

fwiw, I would do a 1 liter "vitality starter" (as much as that term makes my teeth ache ) and pitch at high krausen...

Cheers!

 

[Murphyslaw11]

fwiw, I would do a 1 liter "vitality starter" (as much as that term makes my teeth ache ) and pitch at high krausen...

Cheers!

Thanks for the advice. I’ll report back in a couple days

 

[smcinco]

Stupid question that would only account for part of the high FG: are you degassing your hydrometer sample?

 

[Murphyslaw11]

Stupid question that would only account for part of the high FG: are you degassing your hydrometer sample?

Yes

 

[JohnDBrewer]

I think your first decoction screwed you. That 10-min rest at 152 was not long enough. You then took that 6-quarts to boil which probably made the bulk of that unfermentable. Should have left that in the 150's for 30-min. Also a pound of caramunich, if treated as a crystal malt does not help your equation.

 

[Beermeister32]

How confident are you that thermometers are accurate?

Ditto. I had a thermometer off once, my mashes came in too high.

 

[Murphyslaw11]

I think your first decoction screwed you. That 10-min rest at 152 was not long enough. You then took that 6-quarts to boil which probably made the bulk of that unfermentable. Should have left that in the 150's for 30-min. Also a pound of caramunich, if treated as a crystal malt does not help your equation.

Thanks for the input. I was worried it was due to the decoction, although I have read that it shouldn’t make the wort any less fermentable. Do you think I should have chosen either Caramunich or a decoction mash, not both?

 

[Murphyslaw11]

Ditto. I had a thermometer off once, my mashes came in too high.

Understood. I was also using a temp gun to verify all temperatures

 

[doug293cz]

Understood. I was also using a temp gun to verify all temperatures

I assume you are talking about an infrared temp gun - is this correct? If so, how did you calibrate it to know it is accurate at mash temps?

Brew on

 

[brewbama]

My PID controller temp sensor was not calibrated. I was not mashing at the temp I thought I was. Once I calibrated it my FG have been spot on

 

[AmarikinBrew]

Simply filtering your water won't stop chloramines. Think of chloramines as chlorine-mines. They do not activate until Co2 is released by any organic matter, to stop germs from proliferating and causing disease. They have no smell or taste to be detected. They are chlorine encased in a biodegradable shell so to speak.

On every brew I make, I treat the mash water with enough campden tablets that have been crushed to a powder. For 6.5 Gal I actually use a penny to measure it. I use just enough campden powder to cover Lincoln's head. Using this measure, yeast is not affected, as well as beer taste in any way.

This is to stop the effect of chloramines, which activate at the time a gas is released (Co2) by yeast.

If you didn't have chloramines before in the public water, the city may have started this activation recently.

 

[doug293cz]

Simply filtering your water won't stop chloramines. Think of chloramines as chlorine-mines. They do not activate until Co2 is released by any organic matter, to stop germs from proliferating and causing disease. They have no smell or taste to be detected. They are chlorine encased in a biodegradable shell so to speak.

On every brew I make, I treat the mash water with enough campden tablets that have been crushed to a powder. For 6.5 Gal I actually use a penny to measure it. I use just enough campden powder to cover Lincoln's head. Using this measure, yeast is not affected, as well as beer taste in any way.

This is to stop the effect of chloramines, which activate at the time a gas is released (Co2) by yeast.

If you didn't have chloramines before in the public water, the city may have started this activation recently.

Chloramines in the brew water can give you off flavors - medicinal or plastic (like band-aids) tastes, but I've never heard of them affecting fermentation. Do you have links to references that show that typical levels of chloramines in water can affect yeast performance? If not, what does your post have to do with the topic of this thread?

Brew on

 

[ClaudiusB]

Simply filtering your water won't stop chloramines. Think of chloramines as chlorine-mines. They do not activate until Co2 is released by any organic matter, to stop germs from proliferating and causing disease. They have no smell or taste to be detected. They are chlorine encased in a biodegradable shell so to speak.

On every brew I make, I treat the mash water with enough campden tablets that have been crushed to a powder. For 6.5 Gal I actually use a penny to measure it. I use just enough campden powder to cover Lincoln's head. Using this measure, yeast is not affected, as well as beer taste in any way.

This is to stop the effect of chloramines, which activate at the time a gas is released (Co2) by yeast.

If you didn't have chloramines before in the public water, the city may have started this activation recently.

"They do not activate until CO2 is released by any organic matter, to stop germs" Am I missing something, Lenntech, and others never mention CO2 must be released first.
Chloramines, like chlorine, are oxidators. Chloramines can kill bacteria by penetration of the cell wall and blockage of the metabolism. Monochloramine is the most effective disinfectant. It reacts directly with amino acids in the bacterial DNA. During deactivation of microorganisms chloramines destroy the shell which protects a virus. When the pH value is 7 or higher, monochloramine is the most abundant chloramine.

Read more: https://www.lenntech.com/processes/disinfection/chemical/disinfectants-chloramines.htm#ixzz8lNaUsEJW

 

[AmarikinBrew]

From a now defunct website: http://www1.picobrewery.com:8193/ask.html

Back to Ask the Brewmaster.

This month's question: I heard that LA DWP and other municipal agencies are replacing chlorine with chloramines. What will that do to my beer? Should I make any changes in my brewery?

Answer:
Most brewers know that chlorine can do two things to your brewing process:

Keep your equipment sterile, which is a good thing.
Generate foul-tasting byproducts, which can ruin your beer.
Hence, most brewers have sort of a love-hate relationship with chlorine.

Chlorine is added to the municipal water supply to kill bacteria, fungi, viruses and other health-threatening items organisms. This makes it possible to use municipal water to top up partial boil batches, rinse out your siphon hose and other convenient things. Without chlorine, we would have to boil every last bit of water that ever touches the beer, and rely much more heavily on other sterilizing agents such as iodophor. To the best extent possible, chlorine should be prevented from getting into beer. The reason for this is that chlorine can react with the myriad organic chemicals to create chloroorganics. Some of these compounds have strong undesirable tastes or aromas. Probably the most notable is chlorophenolic, which can form when chlorine reacts with the phenolic components of grain husks, particularly p-hydroxybenzoic acid. Other compounds that can form are simpler compounds such as chloroform.

The municipal process of disinfecting water can create similar chlorinated chemical compounds. Many chlorinated compounds are carcinogenic, so the city has been looking for ways to disinfect water without the use of chlorine. Chloramines fit the bill, so the city is currently in the process of phasing in chloramines and phasing out chlorine. For the next few years, your tap water can have either chloramines, chlorine, or both.

Chloramines are harder to remove from water than chlorine. Chlorine can be removed by letting water stand for 48 hours, or by boiling. However, these don't work for chloramines. Hence, some new tricks are needed. The simplest method you probably already have at hand is carbon filtration. Activated charcoal filters work, but they doesn't absorb as readily as chlorine, so you have to run the water through more slowly. A typical homebrew-sized filter can only take about a pint per minute, so you would have to start early to collect enough for your batch.

If you don't have patience with slow filtration, you can try chemical dechlorinators. Campden tablets, using sodium metabisulfate will do the trick. However, you have to be careful to not overdo it, since excess sulfite can stunt or kill your yeast. A quarter tablet per 5 gallon batch is needed. Ascorbic acid (vitamin C) will work too, and in smaller doses. You need about 4 ppm, or about 0.08 grams for a 5 gallon batch. This is what kidney dialysis systems in hospitals use. Ascorbic acid is probably a better bet, since a bit of extra won't kill yeast. It will bring down the pH of your brewing water, though the amount needed is so small it is unlikely to have much of an impact. If you have plenty of patience, note that chloramines is degraded by sunlight. A week in a carboy outside should do the trick. UV lamps work too.

The good news is that the presence of chloramines in your beer is far less deleterious than chlorine. Keep an eye on your yeast activity. As long as the yeast is doing OK, the chloramines levels is probably OK. Formation of chlorophenolics and other chlorinated byproducts are reduced by 98% with chloramines relative to chlorine. That means even if you do leave some of it in your brewing water, it won't be a significant problem.

 

[AmarikinBrew]

Chloramines have a long discussed history of preventing the expectant attenuation from occurring.
ie. finishing to early.

 

[doug293cz]

Chloramines have a long discussed history of preventing the expectant attenuation from occurring.
ie. finishing to early.

References please.

Brew on

 

[Murphyslaw11]

Simply filtering your water won't stop chloramines. Think of chloramines as chlorine-mines. They do not activate until Co2 is released by any organic matter, to stop germs from proliferating and causing disease. They have no smell or taste to be detected. They are chlorine encased in a biodegradable shell so to speak.

On every brew I make, I treat the mash water with enough campden tablets that have been crushed to a powder. For 6.5 Gal I actually use a penny to measure it. I use just enough campden powder to cover Lincoln's head. Using this measure, yeast is not affected, as well as beer taste in any way.

This is to stop the effect of chloramines, which activate at the time a gas is released (Co2) by yeast.

If you didn't have chloramines before in the public water, the city may have started this activation recently.

You may have missed that I said I used distilled water. Or maybe I’m missing your point. Regardless, thanks for the reply.