Mead has a bitter Off note

[Sean75]

My 3 gallon batch is about 18 days old and has a bitter Off-note. Hoping the experienced mead-makers here might be able to help me figure out what it could be/what I may have done wrong. Here’s the info:

3 gallons spring water
12 lbs wildflower honey
D47 packet
OG 1.107
1 tsp Fermex, 1 tsp Yeast Energizer each day for 3 days
1.75 tsp Potassium BiCarbonate
Racked at Spec Gr 1.003
Cold Crashed 2 days later at FG 0.998, 14% abv

From start to Cold Crash was 13 days

It’s not as hot as I thought it would be at 14% abv but that bitter note is really throwing it off. I poured some off and tinkered with adding honey to sweeten and some acid blend, the overall taste improved but that bitter note was still there. I did a search for the term “bitter” and found nearly 20 others who reported the same problem - concerned because no one who responded to them had any idea what it could have been from - most suggested aging though some of the posters who did age said it didn’t help. Any ideas?

Thanks

 

[Seamonkey84]

That is a very short amount of time to expect it to not taste off. Mead takes time to age, even the fastest ones are at least a month (Brays One Month Mead- BOMM) to let the yeast clean up. Once it ferments dry, it should be allowed to clear on its own for a bit.

 

[SKBugs]

Yep. It’s a journey, not a race. You have to let it age out to take full advantage.
Especially when you have a traditional with a high ABV.
It looks like you are treating it like beer brewing maybe?

 

[Toxxyc]

Yeah if you don't do the science thing a bit and feed them better food than Yeast Energiser, coupled with possibly incorrect temps for the yeast, a high gravity mead and the fact that you racked off the yeast before the fermentation was complete, I would also say that you should give it more time. A few months should clean it up a bit. If not, you can look at fining agents that tackle astringent and bitter notes in meads and white wines. Also look into oaking, it can also clean it up a bit.

 

[Sean75]

That is a very short amount of time to expect it to not taste off. Mead takes time to age, even the fastest ones are at least a month (Brays One Month Mead- BOMM) to let the yeast clean up. Once it ferments dry, it should be allowed to clear on its own for a bit.

I hear ya - it is early - but I've heard of young meads being hot - but never bitter. Have you ever tasted a young mead and gotten a bitter flavor? The other people who asked the same question here noted that the bitter flavor remained after aging.

 

[Sean75]

Yep. It’s a journey, not a race. You have to let it age out to take full advantage.
Especially when you have a traditional with a high ABV.
It looks like you are treating it like beer brewing maybe?

Thanks - yeah it's very early. Did I treat it like a beer? Not on purpose - what would you have suggested? This was my first batch.

 

[Sean75]

Yeah if you don't do the science thing a bit and feed them better food than Yeast Energiser, coupled with possibly incorrect temps for the yeast, a high gravity mead and the fact that you racked off the yeast before the fermentation was complete, I would also say that you should give it more time. A few months should clean it up a bit. If not, you can look at fining agents that tackle astringent and bitter notes in meads and white wines. Also look into oaking, it can also clean it up a bit.

Thanks - a lot of good stuff to unpack there.
So the Yeast Energizer was recommended by the home brew store so that's why I went with it - you'd have used something else? And as for temps, yes, I was on the upper limit for D47. Limit is 68 and my basement was right at 68 and occasionally 69 for a few days. Also, is it the ambient temp we measure or is it the must temp? I noticed must temp was higher than ambient. Do you think that would have an impact - and if so, do you think the bitter flavor would come from that?
Also, I was at 14% abv when I racked it and cold crashed, which is D47's limit, and very close to the planned FG of .998 - Is there any harm in stopping fermentation before the mead goes completely dry? It'd be good to know because I just cold crashed another batch of BOMM - it hit 10% and I really don't want it to go higher. Hoping I didn't screw it up.

Thanks again for the answer - this is really good stuff.

 

[Maylar]

D47 is prone to making fusel alcohols above 65° F, but that wouldn't be interpreted as bitter. I've never used yeast energizer but it's possible that you used more than the yeast could consume and the residual is what you're tasting. I'd be tempted to do a taste test with some energizer in water and see if that's what you're tasting.

 

[Toxxyc]

Thanks - a lot of good stuff to unpack there.
So the Yeast Energizer was recommended by the home brew store so that's why I went with it - you'd have used something else? And as for temps, yes, I was on the upper limit for D47. Limit is 68 and my basement was right at 68 and occasionally 69 for a few days. Also, is it the ambient temp we measure or is it the must temp? I noticed must temp was higher than ambient. Do you think that would have an impact - and if so, do you think the bitter flavor would come from that?
Also, I was at 14% abv when I racked it and cold crashed, which is D47's limit, and very close to the planned FG of .998 - Is there any harm in stopping fermentation before the mead goes completely dry? It'd be good to know because I just cold crashed another batch of BOMM - it hit 10% and I really don't want it to go higher. Hoping I didn't screw it up.

Thanks again for the answer - this is really good stuff.

OK let me be perfectly clear before I continue - I'm no expert. However, I have made some meads and the latest ones are DAMN good after 2 months since making the batch, and it's mostly due to following some rules:

1. I use Fermaid O to feed my yeast, using the TOSNA 2.0 protocol for the specific mead I'm making. I use this calculator to determine what to feed, how much and when: https://www.meadmaderight.com/tosna.html I use Fermaid O because it's an organic yeast nutrient, full of organic YAN, and not synthetic nitrogen like you get in DAP (or Yeast Energiser). Yeast Energiser contains DAP, or Diammonium Phosphate. That's a "synthetic" nitrogen source for yeast, and yeast grows drastically on it (massive colony), but the cells aren't the healthiest. Like raising a kid on McDonalds. Big fast, not big good.

2. It's more important to keep temperatures constant, than in a specific range. Also, measure MEAD temp, not ambient temp. Mead, specially larger batches, can easily be a good few degrees warmer than ambient. Also, yeast is unhappy at too high (or too low) temperatures, but they are unhappier with wild temperature fluctuations. So if your basement is 68°F, rather place the fermenter in a big cooler box and fill that box with cool water, and cover it with a towel and stick a fan on it. That'll keep the temperatures very constant (because of the larger thermal mass), and slightly lower than ambient, and the yeast happy.

3. Never rack off until your fermentation is complete. Unless your fermentation is drastically slow and you're using a very volatile yeast strain that's going to cause off flavours if you leave the mead on the lees for too long, just leave it. If you rack off before the fermentation is complete, you are essentially asking your little yeasty-beasties to finish their fight in the hardest part of it (no O2, no more YAN, high ABV) without the vast majority of the yeast colony. You're asking too much of the last few cells in suspension, and that makes them unhappy.

4. You can't stop an active ferment reliably and easily. An active fermentation is a very, VERY strong process. You can make it slower if you cold crash it, but you can't stop it. If you try to stop it with preservatives, you risk damaging your mead due to unhappy yeast cells. Best is to plan the gravity ahead, hit your specific gravity reliably, ferment to dry, stabilize and then backsweeten to taste. People who claim to have "stopped fermentation" and then bottled... Yoh. You're building little bombs there. These "stopped" fermentations have a way to get going again, sometimes years after being bottled.

5. Making any mead over 10% ABV is more difficult than meads under. The reasons is because you're working with high gravities. Yeast isn't happy with such high gravities, because the alcohol makes them drowsy and drunk and unhappy. Higher ABV levels also mask other flavours and takes much, much longer to age. Around 10 to 11% ABV is, in my mind, the perfect level of alcohol to hit in meads. People often make the mistake to hunt alcohol, then they build a super-high gravity must, pitch yeast and hope for the best. Then the yeast goes into osmotic shock because of the super-high sugar content, make high fusels and esters and the mead needs years to age out. Not good. Rather make a few batches at a lower ABV until you get your groove going, and then try a high ABV mead. I'm not even there yet (and I'm not sure I want to go there at all).

6. If you don't cold crash and leave your mead after fermentation for a week or three, the yeast can often assimilate a lot of the off flavours. It "cleans up" after itself, as we call it. It's never a good idea to rack off the yeast cake immediately when you hit a dry gravity. It's not a good idea in beer, it's not a good idea in cider, it's not a good idea in wine and mead is no different. Next time - rather let it sit for a week, or two, or three, or even more, depending on the yeast strain. The mead will also clear out better on it's own if you allow that.

Now, taking all the above into account, I have never worked with D47. D47 is a temperature sensitive yeast, but it shouldn't make the mead BITTER. It's not impossible that you're mistaking a very dry mead with higher astringency with "bitterness". I don't know how it happened - maybe there's an infection in there somewhere, maybe your honey varietal has a bitter note (which will shine in a 14% dry mead made from it), but I don't know.

 

[Sean75]

OK let me be perfectly clear before I continue - I'm no expert. However, I have made some meads and the latest ones are DAMN good after 2 months since making the batch, and it's mostly due to following some rules:

1. I use Fermaid O to feed my yeast, using the TOSNA 2.0 protocol for the specific mead I'm making. I use this calculator to determine what to feed, how much and when: https://www.meadmaderight.com/tosna.html I use Fermaid O because it's an organic yeast nutrient, full of organic YAN, and not synthetic nitrogen like you get in DAP (or Yeast Energiser). Yeast Energiser contains DAP, or Diammonium Phosphate. That's a "synthetic" nitrogen source for yeast, and yeast grows drastically on it (massive colony), but the cells aren't the healthiest. Like raising a kid on McDonalds. Big fast, not big good.

2. It's more important to keep temperatures constant, than in a specific range. Also, measure MEAD temp, not ambient temp. Mead, specially larger batches, can easily be a good few degrees warmer than ambient. Also, yeast is unhappy at too high (or too low) temperatures, but they are unhappier with wild temperature fluctuations. So if your basement is 68°F, rather place the fermenter in a big cooler box and fill that box with cool water, and cover it with a towel and stick a fan on it. That'll keep the temperatures very constant (because of the larger thermal mass), and slightly lower than ambient, and the yeast happy.

3. Never rack off until your fermentation is complete. Unless your fermentation is drastically slow and you're using a very volatile yeast strain that's going to cause off flavours if you leave the mead on the lees for too long, just leave it. If you rack off before the fermentation is complete, you are essentially asking your little yeasty-beasties to finish their fight in the hardest part of it (no O2, no more YAN, high ABV) without the vast majority of the yeast colony. You're asking too much of the last few cells in suspension, and that makes them unhappy.

4. You can't stop an active ferment reliably and easily. An active fermentation is a very, VERY strong process. You can make it slower if you cold crash it, but you can't stop it. If you try to stop it with preservatives, you risk damaging your mead due to unhappy yeast cells. Best is to plan the gravity ahead, hit your specific gravity reliably, ferment to dry, stabilize and then backsweeten to taste. People who claim to have "stopped fermentation" and then bottled... Yoh. You're building little bombs there. These "stopped" fermentations have a way to get going again, sometimes years after being bottled.

5. Making any mead over 10% ABV is more difficult than meads under. The reasons is because you're working with high gravities. Yeast isn't happy with such high gravities, because the alcohol makes them drowsy and drunk and unhappy. Higher ABV levels also mask other flavours and takes much, much longer to age. Around 10 to 11% ABV is, in my mind, the perfect level of alcohol to hit in meads. People often make the mistake to hunt alcohol, then they build a super-high gravity must, pitch yeast and hope for the best. Then the yeast goes into osmotic shock because of the super-high sugar content, make high fusels and esters and the mead needs years to age out. Not good. Rather make a few batches at a lower ABV until you get your groove going, and then try a high ABV mead. I'm not even there yet (and I'm not sure I want to go there at all).

6. If you don't cold crash and leave your mead after fermentation for a week or three, the yeast can often assimilate a lot of the off flavours. It "cleans up" after itself, as we call it. It's never a good idea to rack off the yeast cake immediately when you hit a dry gravity. It's not a good idea in beer, it's not a good idea in cider, it's not a good idea in wine and mead is no different. Next time - rather let it sit for a week, or two, or three, or even more, depending on the yeast strain. The mead will also clear out better on it's own if you allow that.

Now, taking all the above into account, I have never worked with D47. D47 is a temperature sensitive yeast, but it shouldn't make the mead BITTER. It's not impossible that you're mistaking a very dry mead with higher astringency with "bitterness". I don't know how it happened - maybe there's an infection in there somewhere, maybe your honey varietal has a bitter note (which will shine in a 14% dry mead made from it), but I don't know.

Thanks so much - this was very helpful.
I really appreciate you taking the time to hit all the points - going to make some changes with future batches. I like the idea of the Fermaid O, the sticking to lower gravity meads and the idea of not being in such a rush to rack.

 

[loveofrose]

There is one thing everyone has missed. You should only use 1/4 tsp (2 grams) of Potassium carbonate per gallon. Too much leads to a bitter metallic note. Try putting some in a glass of water and tasting to see if that is the bitter note. Do the same thing with nutrients so you know what they taste like.

 

[Sean75]

I knew I used too much. Ugh.

Thanks though! Live and learn.

 

[Toxxyc]

You're more than welcome, mate. We all start and "live and learn", like you say. My first batch of mead was honey, water and a cider yeast, all pitched together in December South African heat (95°F+), and left to ferment for a week. Racked, bottled and thought I had "mead".

What I had was a 15% ABV jet fuel. Since then I've learned so damn much, some things are just second nature by now, like using RO water for my batches, never boiling my honey (or even heating it up anymore), properly rehydrating my yeast, using Fermaid O according to the TOSNA 2.0 protocols and, most importantly, keeping my fermentation temperature steady and stable. I'm primarily a beer maker, but mead has started tickling a fancy and I almost always have a 5~6 gallon batch doing something, somewhere at this stage. Actually have 6 gallons clearing on an experimental form of bentonite as we speak. Doesn't seem like it's working, but hey, that's how we learn

 

[Miraculix]

I knew I used too much. Ugh.

Thanks though! Live and learn.

Make another mead according to what @Toxxyc explained very well, use less potassium carbonate and mix it with the finished mead till you get the desired level. That's how you could rescue it.

 

[Toxxyc]

Make another mead according to what @Toxxyc explained very well, use less potassium carbonate and mix it with the finished mead till you get the desired level. That's how you could rescue it.

This. Or you could dry-hop it for flavour and aroma, which could possibly hide the bitterness very well.