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Wild yeast fermentation slow

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Still struggling with this batch. I have summarized all of the previous updates into the post below and added a few more steps that I have taken. Looking for some feedback as to what to try next? Pitching the 71B has it making very slow progress(0.002/week), but I am concerned that it will eventually just stop again altogether. Do I wait and see if this happens and then try pitching EC-1118? Should I try making a starter with DME, some of the must and 71B and then pitch that?

Thanks again, Adam


Wild yeast fermentation slow
Recipe/Process:

Oct 10
~6gal of SG 1.060 - from washed capping
Left for 1 week - fermentation was well started with wild yeast
added 5kg of honey - SG 1.120
2.5tsp of nutriest
1.5 tsp of energizer

Nov 18
Racked to secondary - SG 1.090

December 3, 2015
Added 21g of Potassium Carbonate to raise PH to 3.5
Gave it a good stir to aerate.

December 6, 2015
No airlock activity
SG 1.090
added 21g of P. Carbonate - PH3.8
add 1 tsp of Fermaid-K

Dec 7, 2015
Rehydrated 6g of 71B-1122 per Lalvin's instructions and pitched

Dec 8, 2015
Fermentation restarted - still very slow.

Dec 9, 2015
Air lock activity still really slow
Stirred and added 1/2 tsp of DAP

December 21 2015
SG 1.086
Rehydrated 10g of 71B-1122 in Go-ferm per instructions and pitched

Dec 30 2015
SG 1.083
PH 3.6
Very slow air lock activity
 
My goodness. That is getting a slow start. It's been three months. That 71B ought to have done the job by now. Do you have the inclination/ability to Oxygenate with pure oxygen? Might try that or some other forced source of clean/sanitary air. Also haven't looked through all the posts above thoroughly but what temp is your must sitting at? Many wine yeasts like to get really warm to get started (like mid 70s) then cool down for the long haul (low to mid sixties). More experienced yeast-ologists may need to chime in here with more exact numbers.
 
Ok I just found your early post citing 18-20C. Assuming that's been constant I'd recommend raising the temp to somewhere in the 24-26C range for a few days. Then if fermentation kicks in, let it settle back down to 18-20 again.
 
I have tried really stirring it well to oxygenate several times and have been stirring every couple of days. I don't have a method of oxygenating with pure oxygen. I was concerned about how much oxygen to expose it to at this point - I didn't want to cause too much oxidization?

I don't have an easy way of raising the temperature to the 24-26 range this time of year - might be able to rig up something if this is the way to go.
 
Temperature may help, although 20C is above 71b's minimum tolerance of 15C. I think 71b may be a bad choice to restart a wild fermentation. Since you mentioned ec-1118 I guess you knew this so I won't go into too much detail. Lalvin also mentions k1-v1116 as good for restarting stuch fermentations. My guess is that repitching k1 or ec will solve your problem. If this fails there is something wrong with the must or in your way of preparing the yeast. Maybe you would need to add yeast hulls to absorb toxins or something... However at that point I would personally probably start another batch and combine the two once fermentation is strong. The yeast should be able to complete the fermentation of the larger batch if enough yeast and nutrient was pitched
 
Thanks. I did know that EC-1118 would probably be better than 71B for restarting, but I was concerned with the end result being too dry. I didn't realize that 71B is a poor yeast for restarts. I found this restart method on the Scott Labs website:

http://scottlab.com/uploads/documents/downloads/136/2010RestartStuck.pdf

I don't have a local source for K1-V1116 or yeast hulls, but I could follow the rest of the procedure using EC-1118. Any thoughts?
 
So what does that mean in terms of whether the EC 1118 would be appropriate to try to restart the mead with 71B1122 already in it? And where do you go to look these things up and learn more?
 
Mazer828 said:
So what does that mean in terms of whether the EC 1118 would be appropriate to try to restart the mead with 71B1122 already in it? And where do you go to look these things up and learn more?
Click to expand...

It means that if you add EC to a must containing 71B the EC will make the K2 kill factor and kill off the 71B. This would be a bad thing if you wanted to do a mixed fermentation, but since you're restarting a stuck fermentation the 71B isn't active anyway so who cares.

Edit: The Scott Labs Fermentation Handbook has charts comparing all their yeast stains. They note which stains are kill factor positive, neutral, or sensitive. Just Google it and it can be downloaded as a pdf.
 
Thought I would post an update. The Scott Lab procedure is looking successful. I initially thought it was a flop, but there was just more lag than I expected.

​Jan 11 2016
S.G. 1.081
Followed Scott Labs procedure for stuck fermentations minus the yeast hulls.
Used EC-1118 yeast

Jan 12 2016
Stirred
No activity

Jan 13 2016
Stirred
Not much activity

Jan 16 2016
Good airlock activity
SG 1.060
Stirred.
 
I have a question. Do you realize that you need to have your yeast slurry and your must within 10 degrees of each other before you pitch? If not, you could be killing as much as 75% by tossing it (yeast) into a must colder than a 10 degree separation.

It's also hard for your yeast to go from a extremely low SG in the slurry and then dump it into a 1100 or greater due to osmotic pressure.

If you do the go-ferm thing,,, after 15 minutes start adding about 1/3 the amount of must to your slurry and stir. Do this several times every 10 or 15 minutes apart until your temps are closer than 10 degrees separation. In doing so you draw the temps together and you gradually raise the SG over time so it's not so much of a shock going from one environment to a totally different one.
 
Yes. When I rehydrated the 71B, I followed the Go-Ferm instructions precisely, including ensuring there was a less than 10 deg temperature differential as well as acclimatizing. The Scott Labs procedure takes it a step further. You make a weaker 50/50 must/water solution with 10% of your must and then add the remaining must in 30 minute intervals. It also calls for rehydrating the yeast in Go-ferm.

Looking back, my conclusions are that the wild yeast stopped due to high acidity. I made the huge mistake of racking before testing my SG. Once I realized there was a problem and that it was PH, I corrected it. There wasn't sufficient wild yeast left to get started again. I am not entirely sure why the 71B was unable to restart it - perhaps it's just too fussy to be used to restart a stuck fermentation.

I am more familiar with making wine and cider which is significantly less fussy. It is apparent that I need to be more careful when making mead.
 
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