Stuck Fermentation: PH problem?

[eric_pwb]

I have been searching around for an answer for the last few days, but have been unable to determine the cause of my problem. I am currently making (4) 5gallon batches of mead, all with different fruits except one.

The first contained 23# of honey, water to make 5 gallons and 18# of strawberries. The second also 21# of honey, water for 5 gallons and 24# of the frozen three berry blend (from costco). The third contained 23# of honey and 15# of handpicked sour cherries. The last just 23# of honey and water for 5 gallons.

For each of the 4 I used Wyeast 4184 (sweet mead) along with a total of 1tsp of yeast energizer and 2tsp of nutrient (blended together, and added in 3/4tsp increments staggered throughout the fermentation). The first three vigorously fermented to completion in about 14 days (at 22C) , however the last initially fermented slowly, and has stalled. It started at a gravity of 1.129 and 12 days later is still at 1.098. After 5 days with very little activity I pitched another 1L starter (1/2 cup honey, 1/4tsp nutrient, and 1 pack 4184), with very little improvement in activity.

The only difference in conditions between this problematic batch and the other three was the lack of fruit. I am curious as to if it is a problem with my ph, but I do not have a meter or strips to test with. I visited a few LHBS and pet stores and was unable to get any test strips that would test for a ph below 6.

Any ideas?

 

[K5MOW]

Someone else hopefully will give better info them me but at that high gravity I would not have used that yeast. I am thinking of D 47 or 71b

Roger

 

[chickabeelane]

It could be the high initial gravity, or possibly a lack of nutrients. The first three batches have nutrients stored in the fruit, so they can do with less additions. Perhaps you could give the stalled batch a stir and then drop another tsp of yeast nutrient in there, wait 24hrs. Then test gravity again. If that doesn't work, then you would be looking at re-pitching with another yeast (ec-1118, or kv1 IMO)

Cheers!

 

[PCChazter]

Your still in the first third, so nutrient additions and aeration should still be OK. I'm still fairly new at Mead making, but I have had this happen a couple times. For me, because honey has very little pH buffering, my pH went very low very quick. Your other batches have high gravity as well, so it is doubtful that it is that doing it. You could try bringing the pH up by adding calcium carbonate, potassium carbonate, our another carbonate or bicarbonate.

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[loveofrose]

Your problem is very clear. 2 gallons of honey in 5 gallon final volume will be a very difficult ferment. That's an SG of 1.192!

You should use 1 gallon of honey in 5 gallons, let it ferment dry, then add more. That process is step feeding.

At this point, you will need to dilute to 8-10 gallon for a reasonable SG. You may need to re pitch as well with a yeast that isn't so difficult to deal with such as KIV1116, 71B, or EC1118.

 

[PCChazter]

Just out of curiousity, what is the SG and FG of the other 3 that went all the way through?

 

[fatbloke]

Your problem is very clear. 2 gallons of honey in 5 gallon final volume will be a very difficult ferment. That's an SG of 1.192!

You should use 1 gallon of honey in 5 gallons, let it ferment dry, then add more. That process is step feeding.

At this point, you will need to dilute to 8-10 gallon for a reasonable SG. You may need to re pitch as well with a yeast that isn't so difficult to deal with such as KIV1116, 71B, or EC1118.

And also why that damn yeast would have problems! It's got a tolerance of 11% ABV so that's a drop of about 80 or 81 gravity points.

If your numbers are right LoR, then there'd still be enough residual sugars for about another 14.9% ABV.

Using 1.000 as a guide "finished" level, 1.192 points is sufficient for 26.08% ABV and to my knowledge there ain't no yeast that will do that all the time my arse points downwards

 

[eric_pwb]

It could be the high initial gravity, or possibly a lack of nutrients. The first three batches have nutrients stored in the fruit, so they can do with less additions. Perhaps you could give the stalled batch a stir and then drop another tsp of yeast nutrient in there, wait 24hrs. Then test gravity again. If that doesn't work, then you would be looking at re-pitching with another yeast (ec-1118, or kv1 IMO)

Cheers!

I tried adding another dose of nutrient to it, aerating and waiting 24 hours, but my gravity did not drop. I have been stirring a couple of times per day for the last couple days without any results. I was able to get another package of 4184 that I going to make a starter with and attempt to restart fermentation.

Just out of curiousity, what is the SG and FG of the other 3 that went all the way through?

The other three were:
Strawberry/Banana -> SG:1.144, FG:1.022
Blueberry/Blackberry/Raspberry -> SG:1.129, FG: 1.002
Cherry/Vanilla -> SG:1.134, FG:1.024

This batch's SG: 1.132

I have seen a number of posts over the last while with people having issues with the 4184 yeast, but personally I have never had an issue, and this traditional that I am having issues with is the first of 6 total batches that it has caused me a problem. I do however for each batch create a 24 or 48 hour starter to pitch, and with the previous 5 batches I have never had a lag longer than 12 hours, and for most of them I have reached completion under 2 weeks.

 

[fatbloke]

Seems that 4184 either works like a dream or is a complete PITA. My experience of it is the later - 3 times with the same amount of difficulty with it.

Won't be using it again - it's like 5 times the price of a dry yeast that has always worked ok.

If it's worked/working for you generally, then that's great.

Just that I certainly wouldn't entertain using it with such high start gravities. Something like a max of 1.100, and even then, if it's a traditional, I'd likely chuck a tsp of potassium carbonate in to buffer the pH a bit........

But either way, it's your mead so only you can decide how you want to progress with it......

Good luck......

 

[eric_pwb]

Just that I certainly wouldn't entertain using it with such high start gravities. Something like a max of 1.100, and even then, if it's a traditional, I'd likely chuck a tsp of potassium carbonate in to buffer the pH a bit........

I'm curious about your recommendation to add carbonate. It is something that I was definitely considering, but was unsure of the consequences if the ph if the must didn't actually require it.

 

[fatbloke]

Its not automatically needed but given the finicky nature of 4184, I don't know why I had problems with it. Its entirely feasible that it was a pH issue in my case.

You could equally just do lots of tests to monitor or cover your arse a bit by buffering the pH a bit to prevent it dropping too low and causing a stuck ferment.

Equally, given 4184 being quite a low tolerance yeast compared to most wine yeasts, if it did finish excessively sweet, you can reduce a flabby sweetness by adding some acid to drop the pH to a lower balanced level too taste.....

Or even if it still didn't balance quite enough, some liquid tannins can help too.....

 

[PCChazter]

I have also heard about adding cream of tartar (tartaric acid) initially to buffer pH. I don't know how this affects taste though

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