Stuck fermentation

[udiraz]

Hi All.

I started to make a mash from dried apricots. you can see the thread about it here: viewtopic.php?f=38&t=74249.

Well, for the first few days it was bubbling very nice, and than, two-three days ago it got stuck. First it went very slow, and now it is completely stuck.
I tried to put some more yeast (1118) but it did not help.
It stopped at about 1.035 SG, so there is more sugar in it.
We did have an extreme heat wave in Israel ( we had about 40 degrees Celsius), but I did put the yeast also after it went down to normal temperatures. I also have to mention that I fermented successfully grapes in the Israeli summer, so I am not sure that it is the heat that stopped it.

I also tried in one barrel to filter the solid parts, and add more filtered water (to eliminate the possibility of too high alcohol concentration) and add more yeast after dehydrating of course. didn't help.

Any good advice ?
I am really desperate here...

[still_stirrin]

Check the pH.

You may be too acidic for the yeast to survive. If so, add calcium hydroxide to raise pH.

Check it.
ss

[udiraz]

Thanks !
That is the good ph range, and how much calcium hydroxide should I add if I need to correct the ph ?

Thanks,
Udi.

[Saltbush Bill]

What are you basing your assumption that its stuck on?
No bubbles from the air lock?
No visual signs of bubbles on the surface of the wash?
Have you tasted It to see if its still sweet?
All of the gunk in a apricot wash could easily give a false reading on a hydrometer......easier to just blame PH.

[udiraz]

I base on few paraters:
1. no bubbles from air lock.
2. no visual signs of bubbles
3. wash still sweet
4. I also tested with hydrometer, and see that it is not going anywhere

[Saltbush Bill]

Never trust bubbles from an air lock as a sign that something isnt fermenting.
Bubbles on the surface can sometimes be difficult to see....put an ear to it and listen....sometimes you will hear before you see.
Suggest you taste it again to see just how sweet it is.
Because its not going anywhere doesnt mean its not finished ....see post above

[udiraz]

Is it possible to raise ph with baking soda ?

[fizzix]

Is it possible to raise ph with baking soda ?

Yes, but it can easily add a saltiness to your mash.
Fry up some eggs and throw the washed shells into it.

For the future, order some crushed oyster shells (used as chicken feed supplement) and put a fist-sized ball of 'em in a brew sock and throw that in.
The oyster shell will buffer pH ---like on auto-pilot.

[udiraz]

Is it possible to raise ph with baking soda ?

Yes, but it can easily add a saltiness to your mash.
Fry up some eggs and throw the washed shells into it.

For the future, order some crushed oyster shells (used as chicken feed supplement) and put a fist-sized ball of 'em in a brew sock and throw that in.
The oyster shell will buffer pH ---like on auto-pilot.

Thanks fizzix.

How exactly do I use the egg shells ?
How many eggs do I need for a 40 litter mash ?
Do I have to crush them before ?
Do I have to boil them before (germs etc...) ?

Thanks !

[fizzix]

If I were to guess, 4 eggshells minimum. You can boil 'em to be safe, then crunch them up and throw directly in or put in a brew sock and toss that in.
Assuming you'll get some oyster shell for next time ---and even sea shells work--- I wouldn't bother trying to save the eggshells.

They dissolve as needed, and if your pH is really low there may not even be shells afterwards to save anyway.

I've been working with the same oyster shells in brew socks for 8+ months. Never a crash.

[udiraz]

If I were to guess, 4 eggshells minimum. You can boil 'em to be safe, then crunch them up and throw directly in or put in a brew sock and toss that in.
Assuming you'll get some oyster shell for next time ---and even sea shells work--- I wouldn't bother trying to save the eggshells.

They dissolve as needed, and if your pH is really low there may not even be shells afterwards to save anyway.

I've been working with the same oyster shells in brew socks for 8+ months. Never a crash.

Thanks. I really appreciate your help.
Any idea how long it takes to see ph change with egg shells ?

[fizzix]

You know, I really don't know.
Of course the remedy starts working immediately but depends on how low your pH is.

Now this is all assuming pH IS the problem, too. Shells are good insurance regardless,
but let's hope there's nothing else causing your stuck ferment.

[udiraz]

You know, I really don't know.
Of course the remedy starts working immediately but depends on how low your pH is.

Now this is all assuming pH IS the problem, too. Shells are good insurance regardless,
but let's hope there's nothing else causing your stuck ferment.

I just measured the PH, and it was 3.6 - 3.8 does it need adjustment ?
I am almost sure about the ph, because the instrument got mad a little bit after the measure and showed non-sense values thereafter...

But assuming the ph is around 3.6-3.8 - is that too acidic ?

Thanks !

[fizzix]

Yes it needs adjusting. Shoot for 5.5

[udiraz]

Thanks again !

[shadylane]

What are you basing your assumption that its stuck on?
No bubbles from the air lock?
No visual signs of bubbles on the surface of the wash?
Have you tasted It to see if its still sweet?
All of the gunk in a apricot wash could easily give a false reading on a hydrometer......easier to just blame PH.

+1
I'm guessing it's not stalled. The yeast has finished eating what was usable.
Only 1/2 the carbohydrates in the dried apricots was fermentable sugar

[20literpotstill]

I'm mashing about 14 gallons of my Scot's recipe and I paid close attention to brix, SG and pH for the first time. I even adjusted my water's pH before I started to 5.9, then adjusted my mash to 4.3 after mashing in using citric acid powder. I used diammonium phosphate when I pitched my yeast (Lalvin K1-V1116) and aerated for 5 minutes with an aquarium aerator using oxygen. Two days later, it seemingly stalled, so I checked my pH, which was 3.4. I added about 20 tspns of calcium carbonate (maybe more) and some fermax, bringing the pH to 4.3 and the mash came alive. Temp throughout remained at about 88° . I think the "watched pot never boils) analogy doesn't apply to our hobby. There's a lot of things that can go wrong, but it's nice knowing this forum has had every solution I have ever looked for!