Stuck Fermentation.

[jbrew9999]

Since searching didn't help me, I'm hoping some experienced opinions might.

My wash shouldn't be done but has seemed dormant for over a week. I suspect that bread yeast doesn't work below 21 degrees C. Please advise.

This is my first wash. My goal is a clean distillate that I won't have to carbon polish.

~4.7 Kg granulated cane sugar
~1/2 cup food mollassas.
~15g "yeast energizer" (DAP, yeast hulls, B vitamins)
~20-30g "yeast nutrient" (Ammonium Phosphate and urea)
~3 Tablespoons dry acid blend
~30g active dry bakers yeast started for an hour in 28 degree Wash.
Tap water to a little more than 20L

Procedure:
I boiled a couple gallons of water and dissolved the sugar, then added the rest of the water, the mollassas, and the nutrients. I cooled that (covered) in a tub of icewater and played with the pH until It was 3.5 - 4. (I didn't mean to go that low) Once I had ~500ml at about ~28C, I started the yeast in it. Then I whisked the wash for 5 minutes making lots of bubbles to beat in some air. When the wash had cooled to ~29C, I pitched the yeast mixture, dropped in a hydrometer and covered the pot with cling wrap with a hole in it and the thermometer probe sticking out.

The starting gravity was 1.080 and the temp was about 29C.
The next morning the temp was about 22C and there was tons of activity. By that night it was 21C and after 3-4 days it was 18C and there wasn't visible activity so I carefully moved it to a warmer part of the house and wrapped it in a towel where it has sat at about 20C for almost 2 weeks. When I moved it the gravity was at ~1.050. There has been no activity except for one warm day a week ago when the wash temp was 21C and I noticed the SG had dropped to 1.042.

I know from bread making that bakers yeast works fine at around 35C but this site shows that fermentation is much cleaner below 20C. I'm thinking that bakers yeast just doesn't stay active below 21C. Is this true?

What do you think of my:
Nutrient levels?
My pH?
Ingredient ratios?
Procedure?

I now have a new 50W submersible aquarium heater that I'm thinking about dropping into either the wash or maybe in a larger container that I set the wash pot in.

Does it sound like I can warm up this wash and get it to ferment down to closer to 1.000 SG? Or am I going to end up in trouble because of my low pH or perhaps wrong ingredients/ratios.

You help is much appreciated.

[jbrew9999]

Nobody has any coments?

[Watershed]

It should be active below 20 - my bread rises in a freezing cold kitchen ( though it takes its time ).
Smell it - assuming there's a bit of head space, is there any trace of Co2 - the yeast could just be slow.

Don't trust the hydrometer - if you leave it in there gas bubbles and a biofilm of assorted stuff with bugger up your readings - take a sample out to read and don't pour it back.

Try rousing - I've not done it for a while but I used to have to for Yorkshire style beers - take a ladle, give the brew a good stir and use the ladle to raise up and pur back the wort from a foot or so up to get plenty of air into the mix.

If that doesn't work swear repeatedly and repitch using a different yeast and a starter made form 50:50 fresh sugar water and boiled wort.

Your bakers yeast may of course have reached its tolerance.

[jbrew9999]

I set the whole fermenter in a big plastic tub, filled that up with tap water to the wash level and added a 50W aquarium heater. I'm going to try and keep it at 22C-23C. I sure hope I can get all the sugar used up, I don't want it burning to the element.

[junkyard dawg]

I don't have much to add, but sounds like you have plenty of nutrients. What is your alcohol % from a good hydrometer reading? Is it possible that you have reached the max alcohol tolerance of this yeast?

[Guest]

most bakers yeast that I know of will tolerate up to about 14% .
I usually ferment my stuff at around 70*F .

[jbrew9999]

The SG has gone from 1.080 to 1.040 which Tony Ackland's calculator says is ~4.7%. I was expecting over 10% so I think there is a lot of unused sugar in there. The hydrometer is floating in the wash but I bump it around and bounce it a little before I read it.

Now the wash is sitting in a 25*C water bath. If I don't see a gravity change in 24 more hours, I'm going to need more help.

[Guest]

If you don't see a change, Try pitching more yeast and then keep the temperature steady.
You may have just had some bad yeast. It has happened to me before.


Do you use an airlock of any type?

[jbrew9999]

The wash is in a 6 gallon ss pot with cling wrap over the top with a 1 mm hole in it.

The yeast is bulk bread yeast that is kept in the freezer. I've made bread from the same yeast twice since I started the wash. Plus, the yeast was working great in the wash for at least the first 4 days.

I'm reluctant to take the cling wrap off and mess around in the wash because I'm worried about contaminatin. Is it worth it to check the pH? I know the pH was too low when I started (~3.5 before I pitched the yeast). Can a low pH overly stress the yeast?

[Watershed]

I'm reluctant to take the cling wrap off and mess around in the wash because I'm worried about contaminatin.

I fement with just a loose lid and have no trouble. I used to ferment beer open until I got pets.

[possum]

If you dont want to waste your ingredients and are impatient, run your wash, and save everything, boiled mash and singelings. Then put sterile and alcohol free wash with unconverted sugar into a new fermenter and add other fermentables and possibly another strain of yeast. Ive done this with sugarwash when I put too much sugar in my wash for the particular yeast to handle, then on the second ferment got all the sugar out.

[Guest]

I still think you should pitch more yeast and try some kind of airlock. That way you KNOW for sure when it is done bublin.
Pitching extra yeast wont hurt the wash at all. If fermentation doesn't start back up....put the fermenter somewhere cold so that the yeast will drop to the bottom of the fermenter.

[Guest]

It seems that the LOWEST setting on the 50W heater keeps the wash at 26*C which is hotter than I wanted. But the SG is down to 1.035. But doesn't the increase in temperature affect the readings from the specific gravity hydrometer?

Could it be that 1.040 at 20C is the same as 1.035 at 26C? I guess I'll wait and see if it drops further while staying at 26C.

[jbrew9999]

That was me above.

I just tested the pH and it is definately lower than 3.5-- maybe as low as 2.x. In another thread on these forums, someone mentioned using Baking Soda to raise the pH.

I'm going to sleep on it, but I might just run the wash as is and collect the little bit of alcohol present and then add more sugar, more nutrient, adjust the pH and pitch new yeast and let it go again.

[Guest]

Next time give this recipe a try...it is cheaper that using all the wine-making stuff that you used before, and it is a prooven recipe, used by many people.

10 lb sugar
1 6oz can of tomato paste
a little lime juice
red star active dry baker's yeast(21gr or so) or lalvin ec-1118(15-25gr)

[jbrew9999]

Thanks for the recipe. How much lime juice is "a little"?


BTW- The wash is at 20C now so I guess the heater *does* allow it to drop below 25C but it just takes forever to adjust-- The light on the heater stayed on even when the wash was at 25C last night until I turned the thermostat all the way down.

[mmm...tasty]

I come from winemaking background and use this site for a wealth of info. It is the winemaking equivalent to Tony Auckland's distilling sight. This page has stuck fermentation a few paragraphs down.
Steve

[mmm...tasty]

one more time......... oops

http://winemaking.jackkeller.net/problems.asp" onclick="window.open(this.href);return false;" rel="nofollow

Steve

[Guest]

Thanks for the recipe. How much lime juice is "a little"?


BTW- The wash is at 20C now so I guess the heater *does* allow it to drop below 25C but it just takes forever to adjust-- The light on the heater stayed on even when the wash was at 25C last night until I turned the thermostat all the way down.

about a tbspn per 5 gallon wash