How slow is too slow?

[mrflibble]

Greetings!

I've been trying to make mead for about six months and things are going okay, but all my primary fermentations seem slow. Let me give the details of my current batch.

15 lbs local honey for 5 gallon batch
Cooked for 10 minutes at 160
Cooled
Stirred in nutrient and energizer
Pitched two packets Lalvin 71B

Within a day or so the fermentation got very active as I was seeing a bubble in the plastic 'other kind' of airlock (water bell style) every three seconds. A week later the activity is down to very slow (one bubble every 30 seconds). The initial SG was 1.101 and it is now 1.074 making me suspicious.

It wasn't until reading this site and some other sites that I've seen people say that I should stir it during the first three days. The two books I have, don't indicate the need to stir. So I stirred it when I checked the SG. But how necessary is stirring?

Now my first batch seems to have developed a slight bitter end taste. Not too bad, but not ideal and it seems to get better over time. I'm thinking it is because my primary is too slow. Some people say that it is okay, just be patient. The temperature in the room is ~60 degrees which is the low end of the 71B.

My question is, is this too slow? From what I've been reading the lions share should be done in 10-12 days, and that going from 1.101 to 1.074 isn't an active enough fermentation to prevent undesirables from taking hold. Is it a temperature issue? Stirring issue? Should I use more yeast, nutrient or energizer?

Should I just be patient?

Thanks for any help!

 

[Emiroo]

How much energizer and nutrient did you add? Did you rehydrate the yeast before pitching? If so, using what method? Did you add oxygen to the must after heating? (via shaking, direct addition of gas, etc)

60 degrees is pretty chilly- I wouldn't worry about it. Over the winter some of my ales were taking 50% longer than they are currently (15 days instead of 9 for the big boys, 7 days instead of 5 for the little guys). From what I understand, you don't see off flavors until its been in the primary longer than 6 weeks (at least for ale yeasts)

 

[mrflibble]

Emiroo,

Thanks for the quick response!

I don't have my log book here but I add the higher end of the range on the instructions with the stuff. So that would be around 1 tsp energizer per gallon 1 tsp super ferment per gallon. These were mixed in when the must was heating. For the yeast, I followed the directions on the back. Water to 105 degrees, drop in yeast for 15 minutes, stir then pitch.

After pitching I stirred 'vigorously' in my bucket with long plastic stirrer thing for 5 minutes. This wasn't just stirring, I would change directions a lot, go back and forth and generally brutalize my mead.

In my first batch I brewed cold and blended (yes with a blender) the honey and water (1 qt honey to 1 qt water) for all the honey and water, and it behaved fairly similarly. Started off well, then kinda stopped quick.

At this point (and after reading and contemplating the JAO recipe) I think I need to get a pH tester and check the PH. My local water supply is pH 8.3 - 8.5. I filtered *all* my water through a brita filter, but I still might need to check the pH.

Could pH be the issue?

 

[Emiroo]

So I just looked up how temperature effects fermentation and the growth rate at 60 degrees should be 50% the growth rate at 82 degrees. This seems to correspond with what you are observing, so I think everything is happening just as it should.

For what it is worth, if it were my mead I would leave it alone as long as it is bubbling and then check on its progress in another week. You are already over 3% alcohol and your yeast population seems healthy, so I wouldn't worry about contaminants. I'm new to mead so all this is based on how ales behave so if someone more experienced says different, listen to them

 

[Oskaar]

Welcome to the website Flibble.

pH plays an important role, so it is a good idea to know what your pH is and adjust accordingly if necessary. Mead can drop below a pH of 3.0 in the first 24 hours of active fermentation so it's a good idea to watch your pH early on. If the pH is too low your yeast will take off very quickly and then just slow down and stop. Your yeast gets stressed and then your fermentation becomes sluggish similar to what you're describing.

Cooking your must deprives it of oxygen, and cooks off the subtle aroma, flavor and character nuances of your honey, and to me if you're going to cook your must you may as well not spend a lot of time tracking down really expensive honey because you just cook it away.

Your fermentation seems sluggish to me especially with 71B. I'll say it again as I have for the last several hundred times, use the nutrient that the manufacturer recommends for your yeast. Use a nutrient dosing schedule and aerate your must daily until the 1/3 sugar break. You don't need to heat your must. You don't see winemakers boiling or heating their must for a reason.

Fermentation temperatures play a role in yeast kinetics and rapidity of the fermentation. But, each fermentation is different depending on several factors including, pH, initial gravity, YANC, FAN, nutrient dosing, aeration, temperature and turbidity of the must. It's time to dig in and do some research into your recipe and why it may be so sluggish. Hints: nutrient, pH, aeration, initial gravity and pitch temperature.

Cheers,

Oskaar

 

[mrflibble]

Thanks!

Welcome to the website Flibble.

pH plays an important role, so it is a good idea to know what your pH is and adjust accordingly if necessary. Mead can drop below a pH of 3.0 in the first 24 hours of active fermentation so it's a good idea to watch your pH early on. If the pH is too low your yeast will take off very quickly and then just slow down and stop. Your yeast gets stressed and then your fermentation becomes sluggish similar to what you're describing.

I went back and tested it with a strip and it was about 4.0. That's in the normal range right?

Cooking your must deprives it of oxygen, and cooks off the subtle aroma, flavor and character nuances of your honey, and to me if you're going to cook your must you may as well not spend a lot of time tracking down really expensive honey because you just cook it away.

That's how I feel too! My first two batches were all brewed cold, but I figured I should give one a try cooking (not boiling) to see how it varies, and also to see if it has an impact on the fermentation rate.

Your fermentation seems sluggish to me especially with 71B. I'll say it again as I have for the last several hundred times, use the nutrient that the manufacturer recommends for your yeast. Use a nutrient dosing schedule and aerate your must daily until the 1/3 sugar break. You don't need to heat your must. You don't see winemakers boiling or heating their must for a reason.

Wow! I have only checked a few dozen posts here and a few books, but I've never seen this before. It makes total sense, and I'm surprised that more people don't mention it. The packet didn't say anything on the back, I'll dig around their website.

Fermentation temperatures play a role in yeast kinetics and rapidity of the fermentation. But, each fermentation is different depending on several factors including, pH, initial gravity, YANC, FAN, nutrient dosing, aeration, temperature and turbidity of the must. It's time to dig in and do some research into your recipe and why it may be so sluggish. Hints: nutrient, pH, aeration, initial gravity and pitch temperature.

Cheers,

Oskaar

Exactly! I've run multiple batches to try to refine process issues (aeration, sterilization, etc.) and now am trying the cooking to see if it helps. I've been using the same type of yeast (71B) and nutriet type/quantity each time. I now have the pH tester, and I think the pH is ok. The initial gravities are all 1.1+/-0.005 and the initial temperatures have varied from 65 to 80 degrees. None of these things seem to have an impact which is why I've been looking at things I haven't touched, like long term temperature, subsequent aeration, etc.

I'll do more research on the right nutrient level for my yeast.

Another thing is water quality. I was running it through a brita filter first, but my local brew store said I should use it straight out of the tap because the water quality is so good and the mineral content is ideal.

Thanks!

-Andrew

 

[mrflibble]

So I just looked up how temperature effects fermentation and the growth rate at 60 degrees should be 50% the growth rate at 82 degrees. This seems to correspond with what you are observing, so I think everything is happening just as it should.

Wow! Okay, so it should be pretty slow. Where did you find this growth rate info? Is there a link for it?

For what it is worth, if it were my mead I would leave it alone as long as it is bubbling and then check on its progress in another week. You are already over 3% alcohol and your yeast population seems healthy, so I wouldn't worry about contaminants. I'm new to mead so all this is based on how ales behave so if someone more experienced says different, listen to them

Okay. That's what I was trying to figure out, is it something to be concerned about. I was worried about it not getting established well enough to keep out off flavors. I have no problems waiting, I've got lots of basement space. So let's say it keeps fermenting for a looong time, is there any problem with leaving it in the bucket for 2 months (if it takes that long) do I have to worry about the lees if it is active?

Thanks!
-Andrew

 

[Dan McFeeley]

Hello mrflibble --

Welcome to the forums!

It's a little tough to sort out questions on pH, aeration, and nutrients since much of this information is relatively new and not immediately accessible. Old posts by Oskaar, and others, might be your best source on this.

Ken Schramm's book _The Compleat Meadmaker_ is the most up to date resource on meadmaking, but even Ken has moved past the info in his book, plus, it was difficult to get a lot of his then expertise experience in meadmaking into the first edition. I overheard his publisher, at the Chicago meadfest, complaining about space for the book and keeping the material short. ;D The publication powers that be need to touch base with Ken and seriously think about a revised edition of his book.

You can kinda sorta make guesses on this without detailed measurements. In general, darker honeys have the needed nutrients, buffering agents, and mineral content needed to help a healthy fermentation. Lighter honeys need the extra boost. The 1/3 sugar break Oskaar mentioned is something relatively new -- by checking the gravity drop of the honeymust during the active yeast fermentation, you can time the best period for adding nutrients. The most important period is coincident with a drop in the specific gravity, converted to a 1/3 dip in overall sugar content of the honeymust. The known pH window is taken from data first supplied by the late Roger Morse and Keith Steinkraus, first published in the 1960's. No one has updated that information in accordance with currently available yeast strains and their specific pH tolerance. Still, it's a relatively general window and probably good for the average yeast fermentation.

Keep talking, and we'll do the best we can to answer your questions.

 

[mrflibble]

Hello mrflibble --

Welcome to the forums!

Thanks!

It's a little tough to sort out questions on pH, aeration, and nutrients since much of this information is relatively new and not immediately accessible. Old posts by Oskaar, and others, might be your best source on this.

That's what I'm finding out! What I am trying to do is to compile a compare-contrast list of advice. Regarding nutrient I've been trying to dig through the Lalvin site and find their recommendations. I've come across a nice page of downloads and FAQ, but have yet time to read. I'll do that tonight.

Ken Schramm's book _The Compleat Meadmaker_ ...

This is indeed a great book! I agree that it could certainly be larger. When I got some bentonite from my local shop I rushed home to look it up in his book and was disappointed to not find anything. There are many many more things I would like to see.

You can kinda sorta make guesses on this without detailed measurements. [snip]

Keep talking, and we'll do the best we can to answer your questions.

I'll definitely need to read more on the 1/3 gravity drop ideas. I hadn't heard that before, but makes sense. My background is in physics, so I like having curves, and other sorts of data to refer to. I wonder if I can develop a specific 'profile' for a particular strain of yeast for my basement conditions.

Thanks for all the support!

-Andrew

 

[Dan McFeeley]

Your background is physics? Cool. That should work well here.

The 1/3 sugar drop -- are you using a hydrometer? Have you looked into the relationship between specific gravity, Brix, and sugar content of the must? Wine must is about 90% or more sugar content, using both brix and specific gravity measurements, but honey has less fermentable sugar content in honeymust, using the same hydrometer readings for specific gravity and brix.

Keep talking, and we'll help you out as best we can.

 

[Emiroo]

What type of physicist are you? (I'm nuclear)

So, I pulled the growth chart out of a book I am reading called "South African Mead Notes" by E.N. Lear published in 1997 If you are really curious, here is an article that studies the relationship between yeast population growth, nutrients and temperature: http://www.springerlink.com/content/v98g152524j30647/fulltext.pdf

Here is an article about the nutrient feeding schedule from morebeer:
http://www.morebeer.com/public/pdf/wmead.pdf
It translates the 1/3 sugar drop into points brix which is convenient.

 

[Oskaar]

A couple of things to be aware of with elevated fermentation temperature. One is sustained fermentation temperatures over 75 degrees F will definitely get your mead done quicker but you'll also throw off aromas, characters and fusels. You'll end up with a rocket fuel flavor to your mead that will take a long time to age out, if at all.

Keep your ferment temp to 68 - 72 and you'll have a nice rapid fermentation and a great flavored mead. Check out the search tool and do a search on some of my posts about nutrient dosing. 71B is a quick yeast, most of my fermentations with 71B are done in 10 days. I nutrient dose in three stages. I use a rehydration nutrient (Go-Ferm), a mixture of DAP and Fermaid-K at the end of the lag phase, and Fermaid K or Fermaid 2133 at the 1/3 sugar break. I aerate daily through the 1/3 sugar break and then stir or swirl the fermenting must up until close to the end of the fermentation.

Generally when I use 71B I like it in a sweet mead and my starting gravity is about 1.130 or higher so the yeast can ferment to the limit of it's ABV (14%). If you use apple juice the ABV will fly as high as 17% in my experience.

Cheers,

Oskaar

 

[mrflibble]

The 1/3 sugar drop -- are you using a hydrometer? Have you looked into the relationship between specific gravity, Brix, and sugar content of the must? Wine must is about 90% or more sugar content, using both brix and specific gravity measurements, but honey has less fermentable sugar content in honeymust, using the same hydrometer readings for specific gravity and brix.

Until this post I hadn't even heard of brix. So I went and read some resource. Now, how do I fixgure out brix from SG? I've use a hydrometer regularly, but since honey has less fermentable sugar their obviously is some conversion factor right? How do I determine that?

Keep talking, and we'll help you out as best we can.

Oh, I'm a good talker. I'll make you regret saying that.

 

[mrflibble]

What type of physicist are you? (I'm nuclear)

My bachelor's is in physics with a focus on relativistic mechanics. Now, I'm working in software a radiation oncology software company.

Here is an article about the nutrient feeding schedule from morebeer:
http://www.morebeer.com/public/pdf/wmead.pdf
It translates the 1/3 sugar drop into points brix which is convenient.

I skimmed it and it appears with the article I cam across on the lallemand site in their FAQ section. I know just need to figure out how to determine brix.

 

[mrflibble]

Oskaar,

Thanks for all the tips!

A couple of things to be aware of with elevated fermentation temperature. One is sustained fermentation temperatures over 75 degrees F will definitely get your mead done quicker but you'll also throw off aromas, characters and fusels. You'll end up with a rocket fuel flavor to your mead that will take a long time to age out, if at all.

That's good to know! I keep the stuff in my basement, so I don't think I'll ever get that high, but well see in deep summer.

Keep your ferment temp to 68 - 72 and you'll have a nice rapid fermentation and a great flavored mead. Check out the search tool and do a search on some of my posts about nutrient dosing. 71B is a quick yeast, most of my fermentations with 71B are done in 10 days. I nutrient dose in three stages. I use a rehydration nutrient (Go-Ferm), a mixture of DAP and Fermaid-K at the end of the lag phase, and Fermaid K or Fermaid 2133 at the 1/3 sugar break. I aerate daily through the 1/3 sugar break and then stir or swirl the fermenting must up until close to the end of the fermentation.

I read your question to Lallemand on their website, it was well put. They indicated there that since honey was resistant to the same bacteria in wines, that you could add everything up front. So have you found that waiting until the end of the lag phase is actually better? In that article they were suppling numbers in the 1000 gal range, so do you use the same overall quantities that recipes call for and just spread it out, or do you end up adding more over time? For example my nutrient ('SuperFerment-tm from my store, which I'm assuming is a fermaid-K sort of thing) says 1/2-1 tsp per gallon, let's say 5 tsp per gallon. Do you put 1/2 a lag and 1/2 at 1/3 sugar or do you increase both quantities.

And here's the big question. Should I order Fermaid-K, Fermaid-2133, etc. or are my store's versions ok?

Generally when I use 71B I like it in a sweet mead and my starting gravity is about 1.130 or higher so the yeast can ferment to the limit of it's ABV (14%). If you use apple juice the ABV will fly as high as 17% in my experience.

How does 1118 compare to the 71B? I've read the spec sheets, but I don't know how to translate that (acid titration, etc.) into my level of expertise. Should I be using it because it seems to deal with low temperature better?

BTW:

Last night I checked my batch in had dropped to 1.068 @ 62F. (I moved it too different warmer part of the basement.) I figured this was close enough to the 1/3 point (at least as close as I could figure given my current understanding of brix) so I went ahead and dosed with my 'nutrient' (the Super-Ferment stuff) based on the Lallemand article that you started with your question in the "Mead and Wine' article. I'm assuming that Oskaar is you. And I stirred. The stuff certainly seemed a little happier this morning, so I think it things are okay. The odors are good, and the taste is good.

 

[Oskaar]

Yup, that Oskaar from the Lallemand website and I are one in the same, LOL.

OK when I say use the Lallemand nutrients I mean, really, use them, not some other manufacturer's brand. I'm a big believer in the synergy created by a yeast and the nutrient specifically designed for that yeast by the manufacturer. Don't assume that one nutrient is the same as another any more than you can assume that two identical fermions may occupy the same quantum state.

I've found that oxygenation of the must prior to inoculation, and addition of nutrient (DAP and Fermaid-K) at the end of the lag phase greatly improves both fermentation speed, health and vigor. I also prefer to use a scale to weigh my nutrient dosages, and any other additions I make to my meads/wines/beers.

And if you have not guessed by now, yes, order Fermaid-K. Try here they get the orders out right away and will make them right if they don't.

EC-1118 and 71B-1122 are two very different yeasts. One is a Pris de Mousse strain (1118) used heavily in the secondary fermentation of French sparkling wines, and the other (1122) is a Narbonne strain that is used in making Nouveau Beaujolais known for rapid aging and regulated by French law to be shipped the third week of November. These wines do not age well, and are meant to be served chilled. I'm not a big fan of mead that has been fermented by 71B and aged. I dont' think it stands up to D47 personally. EC-1118 is meant for aging and rapid high ABV fermentations. It is a high sulfite producer and metabolizer during fermentation, if you don't feed it at the recommended times, with the recommended nutrient at the recommended rates be prepared for a mediocre mead or wine.

Keep stirring. Next batch, post up your recipe and I'll show you how to get that fermentation to take off like a rocket. Slow, sluggish, protracted fermentations are unhealthy unless they are designed to use a slow yeast, at low temperatures in certain, very specific conditions. Anyone that tells you mead fermentations should last more than a couple of weeks is not telling you the whole story.

Cheers,

Oskaar

 

[akueck]

Don't assume that one nutrient is the same as another any more than you can assume that two identical fermions may occupy the same quantum state.

Hmm, interesting comparison. Nutrients are anti-symmetric with respect to exchange. Use a different one, get the inverse mead function! So, if I chill the mead and condense the fermion-nutrients into some happy bosons all bouncing around together in a quantized particle-orgy, then I can assume all nutrients are the same?!?

Eureka, I'll go get the liquid helium! I knew that stuff was useful for something.

 

[Emiroo]

I think Oskaar just meant that you will get erroneous results assuming that all nutrients are indistinguishable as you would assuming all fermions are distinguishable. Since nutrients are distinguishable, your mead will turn out badly if you treat them like identical particles

 

[mrflibble]

Wow, lots of great info!

Okay, I measured and stirred and I'm not at 1.060, so we're still going. Still a little slow, but making good progress. So how much Go-Ferm and Fermaid-K should I get? Let's say I'm doing a fairly 'normal' 15lb, 5 gallon batch of mead and I'm going to use D47 yeast. How much of each will I need?

Thanks!
-Andrew

 

[Oskaar]

OK couple of things.

Flibble,

If you read the Lallemand site, or followed my link to Morebeer.com you should have found the appropriate doses of nutrients to use for rehydration, and for addition to your meads. If not do some reading on the Morebeer website. It's contingent upon the meadmaker to to do their diligence and learn how to use the tools available.

Dude, do a little reading! I know you can based on your very good questions.

Emiroo, you nailed it! Never presume that all nutrients are created equal with a little Pauli Exlusion Principle thrown in for fun!

Cheers,

Oskaar