FG 1.03 5 weeks in fermentor

[O-Ale-Yeah]

5 weeks after pitching WB-06 my beer tastes very sweet and the FG is 1.03. I don't know what went wrong. It was supposed to finish at 1.007. I was getting a bubble every second from the fermenter for the first 2 weeks, 1 every 10 seconds in the 3rd week, 1 every 30 on the 4th, and 1 every minute in the 5th. The fermenter was churning really well for the first 9 days so everything looked fine.

Here is my recipe:

5 lb Wheat
5 lb Pilsner
1.5 Munich
1 lb Vienna

60 minute mash at 157 fahrenheit
Fly sparge 170 for 30 minutes
60 minute boil

WB-06 dry yeast rehydrated and pitched into 70 degree wort.
Fermented in a constant 66 degree, dark room.

***Added note: It's definitely not the yeast because I threw a brand new batch of wort mashed at 135 on top of that yeast cake Tuesday and the fermentation has been incredibly active.

 

[tgolanos]

My best guess is the mash temp. 157 is a bit on the higher end, so you may have created too much unfermentable sugar, hence the high gravity and sweetness. How'd the taste compare to the beer you did at 152?

Have you tried stirring the yeast and warming the beer up? You may be able to re-start fermentation, assuming you still have fermentable sugars left.

 

[thehaze]

That's weird seeing that WB-06 is a monster yeast. It's diastaticus and will chew anything. Yeah, the mash temp. seems high, but I guess your OG was even higher. It stopped at 1.030 after 5 weeks. You probably didn't pitch even yeast. And your " constant 66 degree, dark room " regime is not healthy for any yeast. 66F should have been in the first 24 hours. That yeast would have finished in 5-7 days, provided the temperature hit 72-74F at some point during clean up and d. rest. If you are following the " american " fermentation schedule, where everything should be fermented as low as possible, you should probably try something else.

 

[O-Ale-Yeah]

My best guess is the mash temp. 157 is a bit on the higher end, so you may have created too much unfermentable sugar, hence the high gravity and sweetness. How'd the taste compare to the beer you did at 152?

Have you tried stirring the yeast and warming the beer up? You may be able to re-start fermentation, assuming you still have fermentable sugars left.

The brew at 152 came out great. l hit my final gravity and it wasn't sweet. l went for 157 this time to get more body. l was wondering if that was the problem.

 

[O-Ale-Yeah]

That's weird seeing that WB-06 is a monster yeast. It's diastaticus and will chew anything. Yeah, the mash temp. seems high, but I guess your OG was even higher. It stopped at 1.030 after 5 weeks. You probably didn't pitch even yeast. And your " constant 66 degree, dark room " regime is not healthy for any yeast. 66F should have been in the first 24 hours. That yeast would have finished in 5-7 days, provided the temperature hit 72-74F at some point during clean up and d. rest. If you are following the " american " fermentation schedule, where everything should be fermented as low as possible, you should probably try something else.

l'm stuck with the 66 degree house since it's March in the Midwest. What is the "something'" I should try? The packet said it was okay from 59 degrees to 75 degrees and I heard that 1 dry packed was all that was needed for a 5 gallon batch. So 66 degrees is right in the middle of the recommendation. If I mash at 157 I should still be able to hit my target gravity right?

 

[O-Ale-Yeah]

Does that sound like a good active fermentation?

1 bubble per second for 2 weeks
1 bubble every 10 seconds for a week
1 bubble every 30 seconds for a week
1 every 60 seconds for a week

 

[BrewnWKopperKat]

l'm stuck with the 66 degree house since it's March in the Midwest.

Are you attempting to ferment at ambient (room) temperature?

If so, do you know that the room temperature is "stable" (for example, 65 - 67) or does the room temperature vary (for example 60 - 70) during the day?

Does that sound like a good active fermentation?

When monitoring a fermentation, the key attributes that most brewers use are wort/beer temperature and current gravity. It will be easier for the forum to help you if you can use these measurements.

 

[kh54s10]

Does that sound like a good active fermentation?

1 bubble per second for 2 weeks
1 bubble every 10 seconds for a week
1 bubble every 30 seconds for a week
1 every 60 seconds for a week

I would say no. I am not familiar with that yeast, but most should bubble for only 3-7 days, 10 on the outside. After a week or so you may be getting some bubbling. It should be inconsistent and caused by temperature or atmospheric pressure changes.

 

[O-Ale-Yeah]

Are you attempting to ferment at ambient (room) temperature?

If so, do you know that the room temperature is "stable" (for example, 65 - 67) or does the room temperature vary (for example 60 - 70) during the day?

When monitoring a fermentation, the key attributes that most brewers use are wort/beer temperature and current gravity. It will be easier for the forum to help you if you can use these measurements.

Yup, ambient temperature. The temp in the room is a constant 66 degrees. I'm not sure of the temp inside the fermenter. My OG was 1.052 and current FB is 1.03.

 

[GoeHaarden]

Just out of curiosity. How are you measuring your FG?

I always get a little concerned when someone says their beer stopped at ~1.030. Which is typically what a refractometer will show a fermented beer at without doing any calculations...

 

[O-Ale-Yeah]

Just out of curiosity. How are you measuring your FG?

I always get a little concerned when someone says their beer stopped at ~1.030. Which is typically what a refractometer will show a fermented beer at without doing any calculations...

I'm using a hydrometer since alcohol skews the refractometer.

 

[O-Ale-Yeah]

I just thought of something. The yeast is surely not the problem because I threw a brand new batch of wort mashed at 135 on top of that yeast cake Tuesday and the fermentation has been incredibly active.

If the final gravity and sweetness issue is because I mashed it 157, I'm shocked. I didn't know that mashing at 157 could cause a gravity of 1.03. Is that possible?

 

[CascadesBrewer]

WB-06 dry yeast rehydrated and pitched into 70 degree wort.

It is hard to say what is going on here. Like mentioned by others a "healthy" ale fermentation (for most beers/yeasts) is a very active fermentation for 3 to 4 days that slows and is pretty much done by around day 8. You may continue to see bubbles from CO2 off gassing, but fermentation should be done well before 14 days (for most ale yeasts...I had a Saison ferment for 6 weeks).

I do not rehydrate dried yeast. I just sprinkle it onto the surface of the wort after aeration. My understanding is that Fermentis changed their directions to "Sprinkle into wort" because people often do more harm than good when rehydrating yeast.

I am not sure what I would recommend for your beer at this point. Pitching a new pack of yeast might kick start it.

Your 157F mash temp should not be a big issue. It will make less fermentable wort, but not one that would finish at 1.030. It may be "safer" just to shoot for a mash around 153F. Temps in the 158F to 160F range can quickly kill off the enzymes responsible for conversion.

 

[O-Ale-Yeah]

It is hard to say what is going on here. Like mentioned by others a "healthy" ale fermentation (for most beers/yeasts) is a very active fermentation for 3 to 4 days that slows and is pretty much done by around day 8. You may continue to see bubbles from CO2 off gassing, but fermentation should be done well before 14 days (for most ale yeasts...I had a Saison ferment for 6 weeks).

I do not rehydrate dried yeast. I just sprinkle it onto the surface of the wort after aeration. My understanding is that Fermentis changed their directions to "Sprinkle into wort" because people often do more harm than good when rehydrating yeast.

I am not sure what I would recommend for your beer at this point. Pitching a new pack of yeast might kick start it.

Your 157F mash temp should not be a big issue. It will make less fermentable wort, but not one that would finish at 1.030. It may be "safer" just to shoot for a mash around 153F. Temps in the 158F to 160F range can quickly kill off the enzymes responsible for conversion.

I know old school thermometers can be off my 3 degrees. I wonder if my mash was 160 degrees.

 

[CascadesBrewer]

I know old school thermometers can be off my 3 degrees. I wonder if my mash was 160 degrees.

It is a good idea to check that in boiling water your thermometer reads close to 212F. Crushed ice and water can check the low end, but 212F is closer to mash temps. I usually leave my thermometer in in my pot as the wort comes up to boil to 1) know when close to boil temps and 2) to verify that my thermometer is still in calibration.

 

[BrewnWKopperKat]

My understanding is that Fermentis changed their directions to "Sprinkle into wort" because people often do more harm than good when rehydrating yeast.

I don't want to wonder too far into the rehydrate-or-not topic with dry yeast. As I understand it, there is a bunch of research / science behind their E2U program; but not much of it is public at their web site.

THE E2U™ CONCEPT is the result of three years observation in the field, research and tests. In R&D, three years might not seem long. Yet this concept is as revolutionary as it is simple to introduce.

https://fermentis.com/en/our-company/innovation-as-a-driver/

The use of active dry yeast has been widely accepted in the brewing industry as both quality and diversity have been improved considerably in the last decade. In short, the production of active dry yeast starts from a vial with pure liquid culture followed by a series of propagation steps in aerobic fermenters of increasing volume. In the final production fermenter the yeast is grown aerobically. Next the yeast is harvested by centrifugation, concentrated to about 32% dry matter by rotating vacuum filters and dried in a so called fluidized bed dryer in which fast, homogeneous and protective drying is guaranteed. To permit a good resistance to rehydration, the yeast is coated with a protective agent (most times the vegetal emulsifier sorbitan monostearate (MSS)) just prior to drying.

with a chart on some of the pitching options

https://fermentis.com/en/news-from-fermentis/technical-reviews/e2u-direct-pitching/

 

[BrewInspector]

It's mash temp on the high end producing less fermentable sugar chains and 66 degrees fermentation for the duration. Raise the temp somehow at the end of fermentation to aid in completion.

Disregard the bubble count vs time elapsed. Bubbles are not a reliable method of determining fermentation

 

[bracconiere]

this is where i chime in and say, you can always add gluco to it...lol

 

[O-Ale-Yeah]

It is a good idea to check that in boiling water your thermometer reads close to 212F. Crushed ice and water can check the low end, but 212F is closer to mash temps. I usually leave my thermometer in in my pot as the wort comes up to boil to 1) know when close to boil temps and 2) to verify that my thermometer is still in calibration.

So when my water is at a rolling boil, my thermometer should read 210? Water boils at 210 on Olathe Kansas.

 

[O-Ale-Yeah]

It's mash temp on the high end producing less fermentable sugar chains and 66 degrees fermentation for the duration. Raise the temp somehow at the end of fermentation to aid in completion.

Disregard the bubble count vs time elapsed. Bubbles are not a reliable method of determining fermentation

Okay, thanks. I'll know next time.

 

[O-Ale-Yeah]

When I change the mash temperature in brewersfriend it doesn't change the final gravity in the calculation. But, mash temperature does affect final gravity right?

 

[O-Ale-Yeah]

this is where i chime in and say, you can always add gluco to it...lol

What's gluco? Is it glucose?

 

[BrewnWKopperKat]

IIRC, mathematical (aka software) models for estimating final gravity depend on the attenuation percentage for the yeast being used. Brewing software appears to default the attenuation value to a mid-point in the typical range for that specific strain of yeast. The mathematical models I'm aware of (not many) don't attempt to estimate the fermentability of the wort.

A Fast Ferment Test is one way to determine the fermentability of the wort. It can be used when initially brewing a recipe or when trying to determine if fermentation is complete (stable FG within the range expected for the yeast strain) or if fermentation is stuck (stable FG but above the expected range).

 

[bracconiere]

What's gluco? Is it glucose?

gluco-amylase...it's an enzyme that will break down unfermentable sugars to fermentable ones...I love the stuff! i can get a 8% beer instead of 6%, with about the same calories...

https://brewhaus.com/gluco-amylase-enzyme-amyloglucosidase-2oz/

add about 6-7 grams to a 5 gal batch it will finish totally dry...

 

[O-Ale-Yeah]

My thermometer is 12 degrees off. I thought I mashed at 157 but it was surly 169. In Olathe Kansas water boils at 210. My thermometer shows 198 instead or 210. That's has to be why my beer tastes like sugar water and has a FG of 1.03. Dang...

 

[bracconiere]

My thermometer is 12 degrees off. I thought I mashed at 157 but it was surly 169. In Olathe Kansas water boils at 210. My thermometer shows 198 instead or 210. That's has to be why my beer tastes like sugar water and has a FG of 1.03. Dang...

gluco, gluco...will get it dry.... when whiskey distillers use alpha-amylase to convert grains, they HAVE to add gluco to get it totally fermentable...one in the mash, then one in the fermeneter....

 

[O-Ale-Yeah]

gluco, gluco...will get it dry.... when whiskey distillers use alpha-amylase to convert grains, they HAVE to add gluco to get it totally fermentable...one in the mash, then one in the fermeneter....

I've already bottled. Can I pop the tops and add it?

 

[BobBailey]

My thermometer is 12 degrees off. I thought I mashed at 157 but it was surly 169. In Olathe Kansas water boils at 210. My thermometer shows 198 instead or 210. That's has to be why my beer tastes like sugar water and has a FG of 1.03. Dang...

You got it. At that temperature the enzymes would be denatured quickly and have little active time to convert starches to sugars.

 

[Lefou]

Looking at your grain mix I would hazard a guess there SHOULD be enough diastatic potential to properly convert in the mash.
Ten pounds of wheat and Pilsner combined will be more than sufficient.

To yield a highly fermentable wort you can do several things.
Mash at a lower temp (145F-152F), extend the mash time, and add glucoamylase. The glucoamylase is more or less a last resort as it will "dry" your beer and boost your ABV somewhat. Hops will become more noticeable in a dry beer using glucoamylase additions so be prepared for the change.
A bit of background on this drying enzyme ... http://beerandwinejournal.com/brut-ipa-ii/

 

[Lefou]

I've already bottled. Can I pop the tops and add it?

Adding the enzyme to bottled beer risks possible contamination or over-carbing if you have active yeast cultures in the bottles. Your best bet would've been to add enzyme late in the mash or in the primary before capping.

 

[bracconiere]

I've already bottled. Can I pop the tops and add it?

lol, probably get an infection, and it wouldn't be worth the trouble....guess your going to be drinking malt syrup....

and +1 to @Lefou , you'd have to dump all the bottles back into a fermenter then add the gluco, to finish fermentation.....

 

[BrewInspector]

And enjoy a highly oxydised beer.

Just leave it and learn from it.

 

[CascadesBrewer]

My thermometer is 12 degrees off. I thought I mashed at 157 but it was surly 169. In Olathe Kansas water boils at 210. My thermometer shows 198 instead or 210. That's has to be why my beer tastes like sugar water and has a FG of 1.03. Dang...

This is kind of an interesting data point. I would think that a beer "mashed" at 169F would not taste like "sugar water" but would likely taste like "grain water". I know that Beta Amylase denature very quickly in any temps above 158F. I am not positive what the upper temp for Alpha Amylase activity is, but one reason for a Mash Out rest at 168F is that this temp will stop/denature all enzyme activity. I am not sure what a mash in the low 160F range would produce.

Mash temps also do not work like 150F = dry, and 158F = sweet...and 166F = really sweet. For the most part, sugars that humans recognize as "sweet" are the sugars that yeast ferment. Lactose is an unfermentable sugar, but if you taste a spoon of lactose it is just barely sweet. There is also some balance that occurs between the sweetness and body that alcohol provides to a lower temp mash beer vs the sweetness and body that the longer sugar chains provide to a higher mash temp beer.

It's definitely not the yeast because I threw a brand new batch of wort mashed at 135 on top of that yeast cake Tuesday and the fermentation has been incredibly active.

I would also say that the fact that the yeast cake fermented another beer does not mean that yeast was not the issue. I am not a yeast expert, but my understanding is that yeast first build up their cell walls/reserves so they have enough "energy" to make through a few generations and consume sugars. Once they run out of oxygen, they switch to an anaerobic cycle where they produce alcohol and CO2 (and you start to see bubbling in the airlock). One cause of a stuck fermentation is that the yeast switched to the anaerobic phase too early and they did not have the reserves needed, and they dropped dormant before consuming all available sugars. These yeast are still healthy and could ferment another batch of beer (especially if over pitched like would happen with reusing the entire yeast cake).