Stuck Fermentation

[rdm]

I am new to mead making and am in the middle of making my first batch of mead. I expected the fermentation process to take between 2-3 weeks. It's been over two months since I brewed my batch and it appears to only be about half done.

My initial fermentation was quit active. However, it's been over 2 months since I started the fermentation and it has slowed down dramatically. I have kept a log of my observations and activities up this point. What do I need to do to get the fermentation started again? Any help I can get would be greatly appreciated.

Recipe:

Medium Show Mead
13.5 lbs Orange Blossom Honey
4 gallons water
2 tsp. yeast energizer
2 tsp. yeast nutrient
1 liter starter of Lalvin D-47 yeast
OG 1.09
Target FG 1.01
pH 4.6

Log:

11/20/10 - Brew date

11/21/10 - Fermentation activity begins.

11/22/10 - Airlock burps every 4-5 seconds.

12/12/10 - Fermentation has slowed dramatically from the initial fermentation. PH 3.7, SG 1.061, temp 65 F. I added 1 ½ tsp calcium carbonate and gently stirred the carboy trying to minimize oxygenation.

01/08/11 - Fermentation is very slow, SG 1.053, racked the mead, added 2.5 tsp nutrient, PH 4.6, temp 68 F, 5.17% alcohol, ¼ inch of yeast discarded.

1/16/11 - 1 burp/30 sec, temp 73 F

01/23/11 - 1 burp/3 min. SG 1.047, 5.8% alcohol, 69 F. Added 2 tsp nutrient.

 

[Oskaar]

I am new to mead making and am in the middle of making my first batch of mead. I expected the fermentation process to take between 2-3 weeks. It's been over two months since I brewed my batch and it appears to only be about half done.

My initial fermentation was quit active. However, it's been over 2 months since I started the fermentation and it has slowed down dramatically. I have kept a log of my observations and activities up this point. What do I need to do to get the fermentation started again? Any help I can get would be greatly appreciated.

Recipe:

Medium Show Mead
13.5 lbs Orange Blossom Honey
4 gallons water
2 tsp. yeast energizer
2 tsp. yeast nutrient
1 liter starter of Lalvin D-47 yeast
OG 1.09
Target FG 1.01
pH 4.6

Log:

11/20/10 - Brew date

11/21/10 - Fermentation activity begins.

11/22/10 - Airlock burps every 4-5 seconds.

12/12/10 - Fermentation has slowed dramatically from the initial fermentation. PH 3.7, SG 1.061, temp 65 F. I added 1 ½ tsp calcium carbonate and gently stirred the carboy trying to minimize oxygenation.

01/08/11 - Fermentation is very slow, SG 1.053, racked the mead, added 2.5 tsp nutrient, PH 4.6, temp 68 F, 5.17% alcohol, ¼ inch of yeast discarded.

1/16/11 - 1 burp/30 sec, temp 73 F

01/23/11 - 1 burp/3 min. SG 1.047, 5.8% alcohol, 69 F. Added 2 tsp nutrient.

Please take the time to read the FAQ and post your questions in the appropriate area. This was posted in a forum that is not remotely relevant to the subject or question.

Thank you for joining GotMead.Com

Oskaar

 

[Dan McFeeley]

Hard to say -- I can see the fermentation picked up on the 16th, when the ambient temperature was 73 F, other dates it's in the 60s. Where are you keeping the carboy, and did you move it briefly to a warmer spot?

A thought, if you've been keeping the carboy in the basement, or other cool place, is it on the floor? The floor could be cooler than the ambient temperature, causing the fermentation to slow down.

--

 

[AToE]

Temp was my first thought too, but even the cooler 69F isn't really very cool, this seems pretty odd to me, that wasn't a very high starting gravity.

Aeration might have been a problem - oxidization is only a danger after the mead is finished fermenting, or past maybe the 1/2 point (though straight honey meads like this are very hard to oxidize, and I mean VERY hard! Fruit ones damage more easily after fermentation is done). Before the 1/2 point (or some say the 1/3 point) in the ferment aerating is actually a huge help to the yeast, and will not hurt the mead at all.

That said, I still think this should have finished easily a long time ago, I'm interested to see what others' takes are on this.

Welcome to gotmead!

 

[Medsen Fey]

Welcome to GotMead rdm!

I'm not quite sure why this mead got stuck originally. If you built up a starter, the aeration shouldn't have been an issue and a pH of 3.7 wasn't a problem (and didn't need adjustment for future reference). The original nutrient amount was low, and that may be a factor though D47 is usually able to function with amounts as you described.

Racking off the active yeast probably set you back, and now you are trying to get them to grow and divide to replace the ones left behind (which is difficult). This is why we don't recommend racking until a batch is done in most cases.

I'd be curious to know the type of energizer you are using (and what the ingredients are). Some "energizers" just contain DAP and vitamins. Adding nutrient (DAP) at this point isn't going to help much as you are at a point where the yeast cannot assimilate it well. They can take up amino acid nitrogen however, and using a product that contains amino nitrogen could be useful here. Products that fall into this category would be Fermaid 2133, Fermaid O, other organic yeast nutrients, and even GoFerm all of which contain primarily autolyzed yeast.

So here's what I'd do:
1) Add some autolyzed yeast product (even homemade if necessary) about 1 tsp per gallon.
2) Add yeast hulls (ghosts) - about 1 tsp (1 gram per gallon if you have scales).
3) Raise the temp to 73F
4) Aerate the snot out of it.

Hopefully that will wake the yeast up and get them working again.

If not, please see Hightest's instruction for restarting, and get a packet of yeast that are good for a restart (Like EC-1118, or Uvaferm 43).

Endeavor to persevere!

Medsen

 

[rdm]

Thanks for the response. I've been keeping the mead in my spare bedroom which I've kept between 65-70 F. The 73F was an exception and I would say the average temp is about 67F.

 

[rdm]

The type of nutrient I used was a mixture of diammonium phosphate and food-grade urea which I purchased from Northern Brewer. I appreciate the advise guys It looks like I have some more work to do. I'll keep you posted and let you know how it turns out.