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fermentation


LaChascona

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Hello, I have a fermentation predicament I was hoping that someone might be able to shed some light on.

So I wanted to try and make a base for my Gin. The plan was to make 1000 liters/265 gallons with a mash bill of 225kg / 500lbs of malted barley, 50kg / 110lbs of malted wheat and 25kg / 55lbs of malted rye. Cooking times and temps were no different then when I make a beer. Before I went over to the boil my SG was 1.070. I boiled for only 10 mins and then into the fermenter it went. I cooled it down to about 14c / 57f. Normally a beer wouldn't be that cold but its winter down here in Chile and the tap water through the heat exchanger was super cold. 

I want to try a new yeast. It's supposed to be this "super yeast" because it will ferment at temps ranging from 10-25c / 50-77f and an alcohol tolerance of 16% or more. It is called EC-1118 and I pitch 500grams although I only really needed 250g....according to the packaging.

The tank temp stayed around 14c / 57f for a week. After a week the bubbling had stopped. I checked the SG and I was at 1.024 or 6%abv. I was hoping the super yeast would be giving me 9%... So, blew CO2 into the bottom of the tank to pick up all the yeast that had settled, heated the tank up to a temp of 18c / 64f and let it sit for another week. The temp eventually went back down but never got below 10c / 50f.

Today, a week later I checked the SG and I'm still at 1.024. The yeast is known to work at temps ranging from 10-25c / 50-77f so I don't get it. 

Does anyone have any experience with EC-1118 or any ideas to what might have happened? Also, How would I go about restarting it? EC-1118 is a "killer yeast" which I have never used before, but it's supposed to kill other yeast that might be present. So, I'm thinking it could be an issue if I pitch another yeast strain...

What do you think? Thanks in advance!    

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EC-1118 is a wine yeast, and while a work horse of a wine yeast, wine yeasts typically don't/can't ferment maltose and maltotriose (sugars commonly produced by alpha & beta amylase in the brewing process). I'm personally surprised it got down to 1.024.

I see 3 options:

1) pitch a lot of healthy active yeast, perhaps a fresh slurry from a near by brewery?

2) if you can let it settle or cold crash it, then rack it you could get most of the EC-1118 out, and then pitch a brewers or distillers strain to mop up the last of the fermentables.

3) you could just distill it and not use EC-1118 again

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1 hour ago, Silk City Distillers said:

Never had an issue with EC-1118.  It's a fast, clean fermenter in the low/mid 70s.  Routinely 0.998 with grain.

 

That's interesting. I have never tried using a wine yeast because of what a wine yeast supplier had told us in regards to maltose. Silk City, are you using any enzymes?

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I would imagine it would take weeks to ferment out a 1.07 sg in the mid to low 50s, if it even finished at all.  It's highly likely that your yeast are simply flocculating and dropping out before fermentation is complete.  Even the start of fermentation would have been significantly dragged out pitching into a 57 degree tank.  A typical ale yeast would have the same problem.

Fix your jacket temperature issues and pitch warmer.  Depending on how cold your ambient temperatures are, you might find you need to pitch even warmer, to be able to keep tank temps elevated through lag phase.  Target something closer to a high 70s pitch.

Once you start fermenting in earnest, the yeast should throw off enough heat to keep the tank temps warm enough.  The challenge is starting off warm enough so that you don't fall back into the 50s before fermentation is complete - as you'll stall.

We deal with similar issues fermenting in the winter as we operate in a non-conditioned space.

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I had issues with getting too cold last winter and had to add heat at the bottom of the tanks to keep it mixed.  Once the yeast slowed down there is not enough natural turn over to keep it warm and mixed.   Having the heater at the bottom fixed the issue.   I have not used ec1118 recently, but I would guess your stopping was heat related or you had a ph crash. 

Start ph looks good. 

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I don't understand the need to boil the mash when you're making a malted mash.    If you have a stuck ferment it is better to rack and repitch than trying to agitate it.  However, I'd probably run the wash and start over to limit spoilage and see if the problem is repeatable.  Ec1118 can survive really low pH (3-4) but it will ferment very slowly (regardless of yeast strain).

Yes your ferm is too cool - try upper 60's to start and don't cool if you can't keep the ferment over 65F.  

My question for you:  have you had successful fermentations before with another type of yeast?  The issue may not be the yeast but available sugars, pH, or excessive/deficient minerals (from your water). 

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Roger-I boiled the mash because I'm a newbie to distilling and I thought it would do no damage..... I can boil a beer as I add my hops and herbs for different intervals and it doesn't effect the fermentation, so I thought it would do nothing but kill any weird stuff inside... 

Silk City- I'm going to check the ph first thing tomorrow.

Bluefish- Temp related is what I'm leaning to..... when you where using EC-1118, was it with a grain mash bill?

Nabtastic- rookie move on the boil? ....ok got it. Ferm too cool, makes sense now. Fermentations with other yeasts have been fine but this is the first time I have tried a high alcohol wine yeast. My last batch was not as bad but also had a lower yield then expected..... So, I'm in Santiago, Chile. Water quality fluctuates but really only the ppm, not bacterias. The fact that it is winter and the rainy season means that there is more surface water coming off the Andes Mountains going into the system.....I never even thought about this. Before I started cooking the ferment that I'm currently having the issue with, I checked the dissolved solids..... only because I just bought a meter. It was over 900ppm. I thought it was high because in the booklet that it came with it says that the EPA does not recommend drinking anything over 500ppm. Do you think that could have an effect? 

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Your grain may not have converted all the way before you boiled and killed off the enzyme activity. Think that's why Roger and nabtastic asked about the boil. Are you fermenting on the grain? If so the amylase enzymes will continue to convert during the fermentation, as long as you don't raise them above 168F. That's why you can get such low finishing gravities with grain spirits as opposed to beer.

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No, I'm not fermenting on grain. I do everything like a brewery because of my past experience and the equipment that I have. I cook the mash, remove the grain, boil the wort, then pump into the fermenter. It's just like a beer but I'm not adding hops during the boil....and I only boiled for 5 or 10 min, not the hour I would do when making a beer. 

Thanks for the insight. I didn't think about that. But if my gravity was 1.070 after the boil, doesn't that mean it was converted?

Thanks! 

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I have not done an all grain with ec1118, but have done a few sugar/ grain mixes.  It fermented very vigorously and finished well.  I would guess the lack of heat was your main issue.  

Next time skip the boil. It is not needed. Just mash, chill and ferment. 

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Depends on your conversion temperature and your grain bill. Hotter it is the more sugars will be converted to unfermentable sugars due to the enzymes that thrive. They still register in your gravity, but don't ferment out. That can be good in beer for flavor and mouthfeel, but is a waste in spirits. 1.024 out of 1.070 does seem like a lot of unfermentables though, so it may be one of the other things mentioned. Just one possibility to think about.

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On 6/29/2017 at 3:42 PM, LaChascona said:

Roger-I boiled the mash because I'm a newbie to distilling and I thought it would do no damage..... I can boil a beer as I add my hops and herbs for different intervals and it doesn't effect the fermentation, so I thought it would do nothing but kill any weird stuff inside... 

Silk City- I'm going to check the ph first thing tomorrow.

Bluefish- Temp related is what I'm leaning to..... when you where using EC-1118, was it with a grain mash bill?

Nabtastic- rookie move on the boil? ....ok got it. Ferm too cool, makes sense now. Fermentations with other yeasts have been fine but this is the first time I have tried a high alcohol wine yeast. My last batch was not as bad but also had a lower yield then expected..... So, I'm in Santiago, Chile. Water quality fluctuates but really only the ppm, not bacterias. The fact that it is winter and the rainy season means that there is more surface water coming off the Andes Mountains going into the system.....I never even thought about this. Before I started cooking the ferment that I'm currently having the issue with, I checked the dissolved solids..... only because I just bought a meter. It was over 900ppm. I thought it was high because in the booklet that it came with it says that the EPA does not recommend drinking anything over 500ppm. Do you think that could have an effect? 

Not necessarily rookie, just preference. Bourbon gets boiled before adding niaked barley/enzymes to burst starch grains. 

Your water should definitely be filtered - but especially if it isn't coming from a municipal supply (since you're in the capital I assume this is "tap water"?) High concentrations of minerals will most likely have a negative effect on fermentation/viviability (rates vary depending on minerals).

Since you've had better ferments, I'm guessing the biggest impact will be on fermentation temperatures.  My opinion (humbly) is to run the wash into multiple small batches and try a variety of yeast simultaneously to see which is best suited for your environment. This will also give a better indication if it's a biological or wort composition issue(s). 

Ps you can try an iodine starch test to see if there are large amounts of starch remaining but will not indicate if its non-fermentable dextrines... 

PSS... You like an extra hand down there? I think I've got a passport laying around here somewhere :)

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