Another fermentation/bottling question

[rdpugh]

May 17 I believe it was, I started a mead using
1.5gal honey
4gal. water
Lalvin 1118 yeast(champagne yeast)
yeast nutrient
acid blend (don't remember how much, what ever the packet said)
must temperature 72F
S.G. 1.130
stirred vigourously
then stirred daily

This has been a very slow fermenting mead. In fact, fermentation stopped several times. It got down to 1.080, and then I put two more packets of champagne yeast and that took it down to 1.060 and stopped again. Stopped meaning gravity did not change at all for a week. I added more champagne yeast and that took it to 1.040. I added another two packs of yeast and the gravity is now at 1.030 and has not changed in two weeks. Looking at the hydrometer scale the abv should be about 14%. There is still quite a bit of carbonation in the must, and the airlock is still bubbling slowly. I tasted the mead, and other than it tasting young, it tastes ok. I like sweet meads, dry meads, it doesn't matter. I have a cyser that finished very dry, S.G. 1.110 F.G. 1.000. I am thinking about just going ahead and adding sulphite and sorbate, clarifing the mead, and calling it done. Is there anything else I can do to bring the gravity down some more, or should I just go ahead and sulphite/sorbate it? This is my first mead. I usually make high gravity Scottish Strong ales and wine, and never had problems with slow or stuck fermentations.

 

[Angus]

rdpugh,

I will throw some questions out that will hopefully lead to an answer to your stuck fermentation.

1. Estimate, how much acid blend did you use? Can you get a pH reading? It sounds like the yeast may be getting a beating with something and it could be the acidity.

2. When you say you stirred daily, did this include mixing vigorously to provide oxygen for the yeast in the first 3 days? It may be that the yeast are not able to reproduce enough and the only way you are getting fermentation is when you add new yeast to the batch. This may be a lack of nutrients.

3. How much yeast nutrient and what schedule? Note that beer Wort and wine Must have natural nutrients in them that the yeast need, whereas honey does not (at least not in sufficient quantities). As per item 2 above, the yeast may just not have sufficient nutrient to be able to survive.

4. How do you prepare the yeast? Do you rehydrate with water per the instructions, or just sprinkle it on? Preparing a strong yeast starter might get a sufficiently healthy colony that you will get the Mead down to your goal S.G.

5. How slow is "bubbling slowly"? The batch is clearly still fermenting along, so you may still reach your goal unless it is very slow, i.e. 1 blip per 30 seconds, at which point you can say it has stalled.

Angus

 

[rdpugh]

rdpugh,

I will throw some questions out that will hopefully lead to an answer to your stuck fermentation.

1. Estimate, how much acid blend did you use? Can you get a pH reading? It sounds like the yeast may be getting a beating with something and it could be the acidity.

I don't have pH test kit. I started the batch off without acid blend, and then added it later. I added the acid blend when the gravity hit 1.080. I added it, waited about a week, and noticed no change. Then I added the yeast. I have the acid blend at home, but I am at work now. I don't remember how much it said to use for one gallon. I put enough for 5 gallons into a 5.5gal batch

2. When you say you stirred daily, did this include mixing vigorously to provide oxygen for the yeast in the first 3 days? It may be that the yeast are not able to reproduce enough and the only way you are getting fermentation is when you add new yeast to the batch. This may be a lack of nutrients.

Yes, I stirred vigorously every day for the first 3. Then of course at every yeast addition. I have also been stirring from time to time just to resuspend the sediment on the bottom.

3. How much yeast nutrient and what schedule? Note that beer Wort and wine Must have natural nutrients in them that the yeast need, whereas honey does not (at least not in sufficient quantities). As per item 2 above, the yeast may just not have sufficient nutrient to be able to survive.

I have put in a total of not quite a tablespoon. Most of it was at the beginning, and some more during one of the yeast additions at 1.080 gravity. I don't know what brand nutrient it is. The homebrew store sells it in ziplock bags with the ingredients listed on it with no brand name. This is the only nutrient they sell.

4. How do you prepare the yeast? Do you rehydrate with water per the instructions, or just sprinkle it on? Preparing a strong yeast starter might get a sufficiently healthy colony that you will get the Mead down to your goal S.G.

I rehydrated the yeast in water per the instructions. In fact one of the yeast additions, and I did not mention this, was the slurry left over from my super active 1gal batch of cyser plus another packet. That was also made using the same yeast.

5. How slow is "bubbling slowly"? The batch is clearly still fermenting along, so you may still reach your goal unless it is very slow, i.e. 1 blip per 30 seconds, at which point you can say it has stalled.

I haven't counted in the last couple of days, just have not seen any change in the gravity reading.

Angus

 

[Angus]

Interesting! Can you get some litmus paper to test the pH (they are usually sold at the brew store)? How fast did you drop from 1.130 to 1.080? If it was fairly quick but slowed dramatically after the acid addition, too low a pH may well be the cause.

Nutrient - is it a white powder about the consistency of sea salt? Or is it more of a finer yellow powder like table salt? It could be that you have straight DAP, which is often sold as Yeast Nutrient, and looks like the white sea salt. During the later stages of fermentation, the yeast need additional nutrients including yeast hulls, vitamins etc. This is often sold under the name Yeast Energizer, and may be yellow. You may find a small addition of this powder, or even just some yeast hulls, could get your batch fermenting again.

Angus

 

[rdpugh]

I started the mead on May 17, on May 29 it reached 1.080 and stayed there for about a week, then added the acid. I did not add the acid all at once. I added it over a period of time to see if it needed just a little, or the full amount. When I got to almost the full amount, I stopped as I was not seeing any change. no movement in gravity, then added more yeast. The yeast nutrient is white and looks like coarse salt. I can get litmus paper.

 

[rdpugh]

I got some yeast energizer. Directions said 1/2 tsp per gallon, so I put in 2 1/2 tsp for my 5.5gal. I also go some litmus paper. It said the ph was between 3.6 and 4. What should the PH be?

 

[Medsen Fey]

A pH between 3.6 - 4.0 is considered ideal for yeast. It seems that is not the problem.

 

[Angus]

So the pH is within the limits. Hopefully, you will have some better results with the energizer and will get this one down to you goal.

One other quick point. Acid blend does not affect the fermentation so much as the flavor. It can have an affect when your Must has too high a pH, i.e. above 4, and you need to bring it down to the 3.6 - 4.0 range, but mostly it is used as a balance to the sweetness.

Keep updating the progress as the energizer does it's thing. Good luck.

Angus

 

[rdpugh]

I added the energizer to the mead last night. I am going to give it a few days before I check the gravity again. Would it be a good idea to give it a good stir daily until the fermentation restarts? Or would that start causing oxidation?

 

[Angus]

Definitely no stirring unless it is very gentle to resuspend the yeast, otherwise you are correct in that you will cause some oxidation.

Angus

 

[rdpugh]

It has been 5 days since I added the yeast energizer. The mead has gone from 1.030 to 1.026 in that time. Temperature of the mead is 72F.

 

[Medsen Fey]

Adding yeast hulls (ghosts) 1 gram/gallon can sometimes help a fermentation along a bit, even if some was in the energizer. A little Epsom salt (perhaps 1 gram for the batch) might also gain you a little ground. Lastly, if you raise the temp another 2-3 degrees you might eek out a bit more.