Yeast Off Flavors

[Fabula84]

Hi!

So, after much research, I've decided to post about an off-flavor I'm finding in my beers. I'm hoping I might get some advice on steps to take to find the culprit or eliminate it completely. If I'm missing something obvious, please don't hesitate to let me know. I'm pretty open to trying anything at this point.

First, I’ve helped brew at a few local breweries, ranging from 1bbl to 20 bbl systems, and have never seen this problem anywhere but at my home. I try to follow the same rigorous cleaning steps I’ve learned from those breweries and I know the taste of infected beers, so I’m pretty sure I’m cleaning correctly and do not have an infection to worry about. I’m happy to talk about this more if anyone thinks it might be the issue, though.

At home, I brew 5 gallon batches on an older SABCO BrewMagic system. After at least a dozen batches, I still have these off-flavors. At first, I found the taste to be very sweet, apple-like, and plasticky/band-aid. Then, with research, I started using Campden tablets to treat for chlorine and chloramine, but was still experiencing some issues. So, recently I switched to bottled water to verify the flavors weren’t coming from chemicals in the water. Although the band-aid flavor has dissipated, the sweet apple flavor is still there.

The wort has always tasted wonderful. It’s not until after fermentation that I notice the off-flavors.

From what I’ve read, apple flavor comes from green beer. So, I invested in some Tilt hydrometers, which aren’t perfect but are pretty clear when fermentation has stopped. Then, a couple of weeks after the gravity has stabilized, making sure everything is cleaned up, I transfer to a corney keg.

Most recently, I brewed a Moctoberfest, or basically a Marzen recipe with ale yeast and temperatures. With an actual hydrometer, not just the Tilt, I measured an OG of 1.068 and a FG of 1.009. It boiled a bit long and ended up more concentrated than I planed. Before that, I did a pale ale with an OG of 1.052 and a FG of 1.005.

I’m using US-05 with these two batches. I use a yeast nutrient and single 11.5 g packs of dry yeast. I have not rehydrated because I have found pages and pages of reasons for and against doing so. It's kind of a lot. In the past, I have used liquid yeast, though, with starters, that have ended with the same off-taste in the final results. To help narrow down a culprit, I’ve turned to the dry yeast to maintain a constant for now.

I whirlpool in the boil kettle and drain directly into the fermentor. The most I’ve done for aeration is let the wort pour into the fermenter and then shake it for a few minutes afterwards.

I pitch around 75 degrees and my Tilt hydrometers read a temperature of about 72-73 degrees for the first few days, then it drops to about 68 degrees, where it stabilizes with the ambient temp.

I use a single fermenter because I’ve read that at this level and time frame, autolysis isn’t a concern. Anyway, autolysis supposedly gives a meaty/soy sauce flavor, which is not being identified at all.

I force carb at about 25 psi for 24 hours, shaking and rolling the first five to ten minutes, then drop the pressure down to about 10 psi for a week or so before serving. After a month or so waiting to be served, the taste seems a bit reduced, but still noticeable.

Most of my friends think my brews taste like beer, but agree they are sweet and kind of fruity. They also don’t line up for a second pint too often, which makes me think it’s not just in my head. I’ve also had a friend remark he’s tried other home brews that tasted “normal.”

So, my thoughts are it’s one of the following culprits:

1. Needing to pitch more yeast
2. Needing to aerate more
3. Needing to ferment at cooler temperatures
4. Try to reduce trub (or potentially increase it depending who you ask)

From what I’ve read, none of those should really be issues, but could potentially be culprits. That’s confusing enough to make my head hurt.

For my next brew, a holiday stout, I’m planning on pitching two packets of yeast, using an oxygen stone I just ordered, and fermenting in chest freezer with an Inkbird controller at 65 degrees.

Does anyone have any advice or suggestions on how to approach this issue? Any thoughts on what the problem could be or steps to take from here?

If you’ve read this far, thank you! Again, if I’m missing something or you really think it might be point I’m overlooking, I’d be happy to look into those issues. I’m really looking forward to making a beer people want.


PS

The only beer that didn’t seem to have this issue was a fruity wheat ale. It finished at about 4% abv and had a bunch of blackberry puree in it, so I figured the taste was covered up, but figured it might be worth mentioning.

 

[Miraculix]

For your next brew, ditch the yeast nutrient. I cannot say for sure but I have often read about cases of weird off flavours that were suddenly gone after the yeast nutrients weren't used anymore.

Imo it is also unnecessary. I brewed a lot of great and a lot of bad beer without it.

Otherwise, I have no idea what could cause the issue. Maybe you are super sensitive for the green apple flavour that some yeast produces during fermentation but clears most of it on its own after it finished?

 

[tripeland]

“sweet” can be a sign of oxidation. You mention that you force carb while shaking the keg. This definitely speeds up carbonation but also oxidation unless you can be certain there is no oxygen in the keg headspace. How are you transferring from fermenter to keg?

“fruity” can be a sign of too high temperature during fermentation. Your temperatures seem warm but not off the charts. I’d suggest doing what you can to reduce the wort temperature below 68F before pitching and during fermentation.

 

[McKnuckle]

From my experience with the ubiquitous US-05 and ale yeast in general, I'd start with #3. Pitching at 75ºF and then (especially) fermenting in the low 70's could be producing esters that you don't like. This would especially be true if the temp is actually a bit higher inside the fermenter than you think it is.

Try pitching a full 10º lower, and fermenting no warmer than 68º.

I would abandon the two packs of yeast approach. Over-pitching can also have some problems. A single pack of dry yeast is tried and true for a 5 gallon batch of average OG.

 

[hottpeper13]

Take your ball valve apart and clean it! Only time I got bandaid was from dirty valves.

 

[Fabula84]

Thank you, everyone, for the feedback! I really appreciate the advice.

For your next brew, ditch the yeast nutrient. I cannot say for sure but I have often read about cases of weird off flavours that were suddenly gone after the yeast nutrients weren't used anymore.

I will definitely try leaving it out. I think I read something about this at some point, too, but never really considered it.

I've wondered if I'm super sensitive to it, too. I know for the life of me I can't detect the buttery flavor of diacetyl whenever it's pointed out to me, so maybe I'm just sensitive to certain things.

“sweet” can be a sign of oxidation. You mention that you force carb while shaking the keg. This definitely speeds up carbonation but also oxidation unless you can be certain there is no oxygen in the keg headspace. How are you transferring from fermenter to keg?

I always thought of oxidation as a cardboard taste, but if it causes sweetness, I need to investigate better transfer methods. I have always just transferred with gravity and clean tubing. It might be time to invest in some carboy pressure transfer kits. It can't hurt anything.

From my experience with the ubiquitous US-05 and ale yeast in general, I'd start with #3. Pitching at 75ºF and then (especially) fermenting in the low 70's could be producing esters that you don't like. This would especially be true if the temp is actually a bit higher inside the fermenter than you think it is.

Cool! I haven't heard anything about #3, so that's an excellent direction. It also seems some others are saying that even though #5 is rated for up to 75 degrees, it still throws esters at that temp. I also appreciate the encouragement that a single pack should be enough. I'm curious about what OG you would start considering multiple packs of yeast. Maybe in the 1.07s?

Take your ball valve apart and clean it! Only time I got bandaid was from dirty valves.

Lol, I'll get that pulled apart and do a thorough cleaning! Thanks!

 

[McKnuckle]

Cool! I haven't heard anything about #3, so that's an excellent direction.

I was referring to your original list. #3 was "fermenting too warm." It's not a yeast variety.

 

[Fabula84]

I was referring to your original list. #3 was "fermenting too warm." It's not a yeast variety.

Lol, my mistake. I was just talking to someone about S-04 yeast, so my brain must have still been on those numbers. Thanks again!

 

[TheMadKing]

Thank you, everyone, for the feedback! I really appreciate the advice.



I always thought of oxidation as a cardboard taste, but if it causes sweetness, I need to investigate better transfer methods. I have always just transferred with gravity and clean tubing. It might be time to invest in some carboy pressure transfer kits. It can't hurt anything.

Oxidation of alcohol can turn the alcohol into acetaldehyde which tastes like green apples.

Cool! I haven't heard anything about #3, so that's an excellent direction. It also seems some others are saying that even though #5 is rated for up to 75 degrees, it still throws esters at that temp. I also appreciate the encouragement that a single pack should be enough. I'm curious about what OG you would start considering multiple packs of yeast. Maybe in the 1.07s?

I 100% agree that your temp seems high, I usually pitch and ferment US05 at 63-64F and only raise to 68-70 at the end of fermentation.

Another place to look is hop matter. I have gotten a green-apple like flavor from hop matter in suspension, especially with East Kent Golding for some reason (if you happen to be using that). So you could try using a hop spider, and making sure to reduce suspended hop matter

 

[tripeland]

Oxidation of alcohol can turn the alcohol into acetaldehyde which tastes like green apples.

Combine this with reduced hop bitterness from oxidation and it throws the flavour balance right into sweet territory.

I see many articles saying oxidation as a wet cardboard or sherry taste, but I’ve never experienced that. I think those flavours are only in extreme or long term situations. I have however experienced sweetness and reduced hop flavour/bitterness.

 

[Fabula84]

So you could try using a hop spider, and making sure to reduce suspended hop matter

Great tip! I can definitely make it a habit to use a hop spider. Thanks!

Combine this with reduced hop bitterness from oxidation and it throws the flavour balance right into sweet territory.

That's interesting. I'm definitely learning some new stuff in this discussion.

 

[Golddiggie]

If you are having a hard time chilling down to a better pitch temperature on brew day you could try fermenting under pressure. There's a range of ways to go about it, but they all center around a pressure safe vessel that gets completely sealed and using a spunding valve to let out pressure after a set level. Most information I've found says to not go above 15psi. There is some information out there for people having solid results fermenting at higher pressure levels. Benefits include reduced off flavors that are normally associated with fermenting at higher temperatures (esters that you might not want), reduced risk of oxidization as well as partially carbonating your brew during the ferment process. It can seriously reduce the time to carbonate for a batch.

On my first go at this the batch was fully carbonated in less than a week after going into serving keg. I don't do the rapid forced method (no shaking). Using the 'set to serving PSI (for the correct CO2 levels) and forget about it' has always been my model. I pulled a pint at 6 days from transfer and it was spot on.

Even if you don't do that, make damned sure you properly purge the keg with CO2 to remove all excess oxygen.

Something I've done from early on is transferring from sealed fermenters via a CO2 push. I purge the receiving keg(s) with CO2, then just jumper from the fermenting keg (more than large enough for either 6 or 9-12 gallon batches) to fill. I then do a few more purge cycles for the serving kegs before calling it good. Never had a single issue with oxidization this way. Added benefit is I don't move the fermenter an inch from when I pitch the yeast until I'm going to clean it after the beer has been transferred. I also have zero light strike issues since the fermenters are stainless steel.

I tried to find information about US-05 and how it reacts to fermenting at different temperature ranges. Not surprising that there's no information available (that I could find with a quick Google search). One of the reasons I prefer liquid yeast is they give you this information when it's a factor. At least Wyeast does, which is what I use.

I didn't see it mentioned, so I'll ask... What are you using to sanitize what contacts the wort post boil?

For the water items you mentioned, I'd suggest getting a filter system to install either under the kitchen sink, or in your brewing area to filter the water you're brewing with. There are more than a few that WILL remove anything that could be a negative impact to your brew. I've used these before when I was on city water. Being on well water, I don't have those issues. I DID get a Ward Labs report on my water when I moved in. I'm rather sensitive to chlorine tastes, so I can easily tell when it's present in tap water. I either smell it, or taste it, when others have gone 'taste blind' to it.

Do some small batches testing out the different solutions you've been provided. Basically, change one thing at a time so that you then KNOW what the offending thing was.

 

[Fabula84]

I've heard of spunding and have some corny keg valves to try it out sometime. It seemed a bit confusing, so I've been holding off, but if my issue is a temperature one, then I should definitely look into it sooner. I didn't realize brewing under pressure had that kind of benefit.

To clean I use PBW, and then to steralize, I use Star San. I stir up five gallons every brew day to make sure I'm using fresh product, too, even though I've heard the shelf life is incredible.

For the water items you mentioned, I'd suggest getting a filter system to install either under the kitchen sink, or in your brewing area to filter the water you're brewing with. There are more than a few that WILL remove anything that could be a negative impact to your brew. I've used these before when I was on city water. Being on well water, I don't have those issues. I DID get a Ward Labs report on my water when I moved in. I'm rather sensitive to chlorine tastes, so I can easily tell when it's present in tap water. I either smell it, or taste it, when others have gone 'taste blind' to it.

This probably is a question for another forum I can start up, but since it was mentioned, does anyone have any recommendations on water filter systems? I've been thinking of installing one in my garage where I get my water.

I did brew again Tuesday. I didn't use yeast nutrient and pitched at 67 degrees. I've been maintaining a temp of 65 degrees, and I'll let everyone know the results. Thank you everyone!

 

[Golddiggie]

This is the system I'm using: https://www.amazon.com/gp/product/B002XISS2Y/
I also ordered one to replace the RO unit my mother was using due to it failing. It would not provide any reasonable amount of water flow out the spigot no matter what. That was after it got moved up with us from FL. Installed the Watts system and it's been working like a champ for years.

BTW, you're not sterilize with Starsan (or for brewing), you sanitize.
I mix up 3-4 gallons either on brew day or when I need some.

Picture of one of my (7-3/4 gallon) fermenters fermenting under pressure. The shorter keg in the picture is one of my 6.6 gallon aging vessels. That has one of my dedicated extraction caps fitted. The only difference (for now) between the caps is the one where it's actively fermenting includes a thermowell.

That was actually an early picture of the spunding valve setup I'm using. I've changed out the black line for clear and added a 4oz plastic jar after the valve. I have the jar about half full of Starsan solution so I can see the gas leaving the fermenter. I ordered up some PTC fittings to get that setup with the same type of tubing.

 

[couchsending]

You need to ferment cooler and warm it up. Pitching that warm isn’t horrible but fermenting that warm to start is. You are experiencing acetaldehyde. As fermentation slows you should let the fermentation rise or warm the fermenter to keep the yeast active and help to clean up any byproducts they might have created. You’re doing the opposite by fementing warm then as the yeast slows it’s cooling back down to ambient. Even though it’s still 68 any drop in temp can cause flocculation which in turn means fermentation byproducts don’t get cleaned up.

You need to figure out a way to ferment cooler then warm the fermentation as it slows.

There is zero reason to wait two weeks after a stabile gravity has been reached with a normal healthy fermentation. If you have a successful fermentation and you’re not dry hopping 4 days is more than enough, 2 is probably enough. Extreme autolysis is soy or meaty but autolysis can present itself in many other ways way before you would encounter soy or meaty flavors/aromas.

And yes you’re oxidizing the living hell out of your beer by gravity feeding it into a keg and then shaking it. Invest in a pressure transfer system for your carboy and do some research on how to successfully purge a keg of any and all o2 (filling full of starsan and pushing it all out with Co2) and purge the transfer lines. Don’t ever shake or roll the keg either. If you want to speed up carbonation set it to a higher pressure for a few days then reduce. With 05 I’d recommend trying to start the fermentation at 66and try to control it there for at least 2 days for a simple 1.050 beer.. then you can let it go to 72 or whatever but you need to try to keep it there even when yeast activity slows. Don’t let it fall until 2 days after active fermentation is done.

 

[Brewmasher]

I always fix fermentation problems by:
make a healthy starter
oxygenate
control temp.

 

[mattdee1]

Most of my friends think my brews taste like beer, but agree they are sweet and kind of fruity. They also don’t line up for a second pint too often, which makes me think it’s not just in my head. I’ve also had a friend remark he’s tried other home brews that tasted “normal.”

Yeah, that's definitely a red flag.

So, my thoughts are it’s one of the following culprits:

1. Needing to pitch more yeast
2. Needing to aerate more
3. Needing to ferment at cooler temperatures
4. Try to reduce trub (or potentially increase it depending who you ask

You can confidently scratch #1, #2, and #4 off the list, IMO.

I think the reduced fermentation temperature for S05 is worth checking out but personally, I'm a bit skeptical that alone is going to make the difference between a beer your friends will drink in small quantities to humor you vs. go back to refill until you cut them off.

In other words, this has all the hallmarks of problems with the fundamentals.

- make sure your recipe is tried-and-true. Follow a known-good recipe to the letter - this forum has hundreds of threads on recipes. If you're troubleshooting, I'd strongly recommend starting with a beer that is not dry-hopped because potential problems associated specifically with that will just muddy your findings.
- brew with 100% distilled or RO water and build suitable water profiles using any of the range of tools available. For most cases, you really only need gypsum, CaCl2, and some kind of acid (e.g., lactic).
- make sure everything is clean and sanitary; ball valves need to be disassembled for cleaning regularly because they quickly fill up with really nasty stuff.

If you do all of that then you should get your friends asking for refills in no time, dare I say even with no fermentation temperature control at all. If you can control fermentation temperature then all the better, of course.

 

[Fabula84]

Thanks for all the replies. I wanted to get a couple brews out of the way before updating. I brewed a stout in December, pitched at 65, and kept it at 65. I kegged and bottled it in January, and it came out fine. A little dry, but I figured that’s because I put cocoa nibs in, which was the taste I was noticing

In February I brewed an American wheat. Used RO water, pitched at 65, and kept it at 65. The gravity stabilized after about a week (1.054 down to 1.009), and at the 2-week mark I bumped it up to 68.

For temp regulating, I have a Inkbird connected to a heating pad and a freezer. I set it to 62, and I take daily readings of the brew using a Tilt hydrometer.

I didn’t get around to kegging the American wheat for about a month. It smells and tastes like apples.

I cleaned the same way for each brew and used a full packet of Safale 05.

To clarify, it’s not sour at all. It tastes like sweet apple juice. I keep reading that it’s probably acetaldehyde, but that is supposed to taste more tart like green apples and it should be gone after the month and a half I let it sit.

The other options I found are I have an infection or my yeast was still stressed.

I can’t find any information on infections that cause sweet apple taste, though, and am fuddled as to why the stout would be fine using the same equipment and cleaning procedures.

I also can’t think of what would be stressing the yeast, now that the pitch and fermentation temps are solid.

I’m really hoping it’s acetaldehyde, but would have to guess an infection. How long do I wait before knowing it’s not acetaldehyde?

Also, if you have any thoughts on an infection causing a sweet apple flavor, I’d be curious to hear them. Might help me identify the issue.

Any other thoughts are welcome, too.

Thanks again for all the useful feedback!

 

[AlexKay]

I too had a run of apple-juice-tasting beers. It was in everything (except stouts, which I assume just masked it.). I tried yeast nutrient and aeration; no improvement. The thing that seemed to work was sanitation: I started PBWing my fermenter and disassembling and boiling its ball valve, every time.

 

[Fabula84]

What type of fermenter were you using?

I was using a Catalyst, so there’s no ball valve. But there’s a large butterfly valve. I usually rinse it and the other parts after use, then wash them in the dishwasher. On brewing day, I put assemble it all and put it on a keg/carboy washer. After thirty minutes of running the pump with PBW solution (turning it every now and then trying to get everything equally), I rinse with water and spray it all with StarSan before putting my wort in.

Maybe there’s a part of the Catalyst fermenter I’m not getting?

 

[AlexKay]

I’m using an SS Brewbucket (2 actually, both giving me this problem), so the ball valve is a trouble spot. Your cleaning certainly sounds sufficient to me, but ... maybe there is a part? I just wanted to share my experience so you know you’re not crazy (or at least not uniquely crazy) and to second the idea of some sort of weird infection.

 

[Birrofilo]

What type of fermenter were you using?

I was using a Catalyst, so there’s no ball valve. But there’s a large butterfly valve. I usually rinse it and the other parts after use, then wash them in the dishwasher. On brewing day, I put assemble it all and put it on a keg/carboy washer. After thirty minutes of running the pump with PBW solution (turning it every now and then trying to get everything equally), I rinse with water and spray it all with StarSan before putting my wort in.

Maybe there’s a part of the Catalyst fermenter I’m not getting?

Taps are a pain in the back to clean with certainty of results. One should actually clean them in open and close position. I clean them with hot water and soap and invariably sanitize them with a microwave oven. Microwaves arrive everywhere.

Just use a ceramic bowl - container and fill it with water. Put the cleaned tap in it. The tap must be completely submerged in water. Use a large container. Put in the microwave and let it go at maximum power for 2 minutes or so. 4 minutes will sterilize it and might be beneficial in your case.

Watch the process through the oven window. Wait a bit before touching the metallic tap, that will be hot. Beware of plastic around the tap lever. You can operate a 30" burst.

A chemical sanitizer will only sanitize on the surface (a few microns) of the object. If there is a microfilm of dirt hidden somewhere, the chemical sanitizer will sanitize only the surface of the microfilm and the microbs inside it will be left untouched. A microwave oven sanitizes (or sterilizes) deep inside the microfilm, actually it will kill with 4' treatment any form of life in the bowl which you insert in the microwave.

 

[Fabula84]

I’m using an SS Brewbucket (2 actually, both giving me this problem), so the ball valve is a trouble spot. Your cleaning certainly sounds sufficient to me, but ... maybe there is a part? I just wanted to share my experience so you know you’re not crazy (or at least not uniquely crazy) and to second the idea of some sort of weird infection.

I appreciate it and do feel less crazy. I figure I’m going to feel really embarrassed but keep expecting to find out I’ve completely neglected cleaning something that should have been obvious lol I might need to upgrade to some stainless steel equipment sooner or later.

Taps are a pain in the back to clean with certainty of results. One should actually clean them in open and close position. I clean them with hot water and soap and invariably sanitize them with a microwave oven. Microwaves arrive everywhere.

Just use a ceramic bowl - container and fill it with water. Put the cleaned tap in it. The tap must be completely submerged in water. Use a large container. Put in the microwave and let it go at maximum power for 2 minutes or so. 4 minutes will sterilize it and might be beneficial in your case.

Thanks for the tip! I’ll definitely keep that in mind for pieces I can’t bake.

 

[Morgz]

There is alot of sound advice here, anything I was going to mention has already been said. I had a fermenter valve problem a couple of years back. I cannot remember the flavour (yes I'm Aussie) it threw, but it was definately not green apple, an infection taste and smell. If I think of something I'll jump in again, but I mostly wanted to find out what the problem is when you finally sort it out. Please keep us all updated.

Curious, have you tasted green apple in any commercial beer, mainstream or craft?

 

[Fabula84]

I wanted to update everyone and possibly provide a little help to anyone with similar issues in the future. Here's a list of points I've focused on in the last few brews:

--Stopped using the Catalyst fermenter. Not sure if it was an issue, but I could easily believe something wasn't getting cleaned properly in the unit. I have now been using glass carboys for fermenting.

--Started using blow-off tubes.

--Did some extra cleaning and boiling on the drain valve from my boil kettle to make sure there wasn't something hiding in it.

--Invested in a Jade Hydra immersion chiller to help get the wort down to pitching temp ASAP.

--Been pitching under 70F and triple-checking fermentation is around 65F.

With all of that, I am happy to report 3 successful brews. A 5-gallon pale, a 10-gallon hazy IPA, and a what was basically a 10-gallon strawberry blonde.

Tasters have definitely enjoyed them above and beyond just humoring me, so I am elated. Thank you everyone for the support and advice. Here's to many more happy brews!

 

[Tobor_8thMan]

Watch the primary fermentation temps. Remember, fermentation can add up to 10F to the temp of the wort.

 

[bwible]

Ball valve on a kettle should not be a problem though, since that is being boiled, right?

Take your ball valve apart and clean it! Only time I got bandaid was from dirty valves.

 

[Miraculix]

Ball valve on a kettle should not be a problem though, since that is being boiled, right?

I've read about multiple cases where it actually was the problem because it didn't get your enough...

Theoretically you are right, but practically there seem to be cases where it didn't work as expected.

 

[AlexKay]

Woohoo! Congrats on fixing the problem. Best wishes that it never ever ever comes back.

 

[Beermeister32]

Years ago I was only brewing ales. Sometimes drinking my ales made me sad. Then I bought a mini refrigerator and regulator to really control fermentation temperatures. Biggest change in improving ales. Also make sure your mash temperature gauge is calibrated correctly, and try a mash lower temp maybe 147-149F for 60-90 mins, then ramp it up to 152-154F for a really fermentable wort with less residual sweetness.

Next thing I did with my temperature regulated refrigerator was to step up and produce real LAGERS. That was the second huge leap. It was like getting hit in the head with a 2”x 4”. Dry out your mash with lower mash temps and ferment COLD. Age it out 90 days at 34F. Why the heck didn’t anybody tell me this? WHAT AN IMPROVEMENT!!!

 

[Morgz]

Years ago I was only brewing ales. Sometimes drinking my ales made me sad. Then I bought a mini refrigerator and regulator to really control fermentation temperatures. Biggest change in improving ales. Also make sure your mash temperature gauge is calibrated correctly, and try a mash lower temp maybe 147-149F for 60-90 mins, then ramp it up to 152-154F for a really fermentable wort with less residual sweetness.

Next thing I did with my temperature regulated refrigerator was to step up and produce real LAGERS. That was the second huge leap. It was like getting hit in the head with a 2”x 4”. Dry out your mash with lower mash temps and ferment COLD. Age it out 90 days at 34F. Why the heck didn’t anybody tell me this? WHAT AN IMPROVEMENT!!!

Totally off topic... but your profile picture, is a pic of a very happy man next to his kettle.

I'm dreadding the day where my kettle ball valve gives me grief. It's non serviceable, but I do operate it several times during clean to attempt to clean.

I'm going to give my first lager a crack next month, given the slow turn around, will be ready for summer here in Australia.

 

[Beermeister32]

Pardon my digression, but a lot of those yeast off flavors and sweetness discussed are however mash profile and fermentation temperature related, so they are not as far off as you might think..! Prost!

 

[Morgz]

When I over chill my wort and heat it back up with the belt, I notice a full flavour from the yeast that wouldn't normally be expressed from fermenting at the low end of the recommended temperature range.