Stalled Sugar Wash

[Moonshyner]

Last week I started a sugar wash similar to the Fast Fermenting Vodka (FFV) using dextrose instead of sugar.
I used citric acid to bring the PH down to 5.2
SG was 1.070
Gave it a good blitz with the Bamix stick blender to aerate the wash.
Proofed the yeast and added it to 30°C wash.

Within minutes the activity started.
About an hour later I had to replace the airlock with a blow-off tube as the activity was so turbulent. The next day I put the airlock back.

The wash was kept at a constant 30°C using a heat wrap controlled with an Inkbird temp controller.

After 5 days there was very little activity, according to the airlock, so I took off the lid and checked the SG of the wash.

1.050 was the result.
PH was 2.8

Not being too disheartened, I decided to try and 'fix' the wash.
Gave it a good stir.
Threw in a bit of old Lowan dried yeast (exp 2011), about 1 tsp of DAP and 1 tsp of bicarb soda to raise the PH and waited.

Two hours later....nothing.
Another 2 hours....nothing.

Plan B:
Gave the wash a good stir.
Rehydrated 20g of fresh yeast and poured it in.
About 8 hours later the airlock indicated that the ferment was up and running again.
12 hours after that (today) it was burping every second (a good sign).

I don't know what went wrong at the beginning.
PH was good
Temp was good
Aeration was good

Hopefully my 'fix' will result in a fully fermented wash.

[howard]

maybe don't bring the wash PH down so much, i think the PH will usually drop naturally after fermentation starts.
the PH of my FFVs is around 5.9 after i add 1/4tsp of citric acid, prior to pitching.
i haven't had a FFV stall yet, but for a PH of 2.8, i would gave added something like calcium carbonate to raise the PH.

depending on the vigour of the stir, it's probably not a good idea to aerate the wash after the start of fermentation.

[Moonshyner]

maybe don't bring the wash PH down so much, i think the PH will usually drop naturally after fermentation starts.
the PH of my FFVs is around 5.9 after i add 1/4tsp of citric acid, prior to pitching.
i haven't had a FFV stall yet, but for a PH of 2.8, i would gave added something like calcium carbonate to raise the PH.

depending on the vigour of the stir, it's probably not a good idea to aerate the wash after the start of fermentation.

Hi and thanks for the info and tips.

[Moonshyner]

Update:-

6pm 12/7/22 Airlock bubbling away indicates fermentation is still active. :happy-partydance:

[bluc]

The theory of dropping ph applies more to all grain
All grain has a lot more buffering ability. Being able to hold ph even with low start ph.
Sugar washs ph will drop low fast naturally. Unless you have very hard water(kentucky limestone) you dont need to adjust ph on a sugarhead.

On all grain there is a lot of bacteria on the grain. That causes infection unless ph is low.

But the grain itself adds buffering capability(the bottom wont fall out of ph) the ph will remain fairly stable. Even at low(acidic) start ph.

But if you dont drop the ph you will get infection. Hence the start point of 5.5ish.

An all grain mash will also handle a lot more backset(acid) then a sugarhead.

Just my humble opinion but I think the practice of backset and 25% backset for burbon stem from limestone water of burbon country. Very hard high calcium water. They were getting infections and needed 25% backset to get the infections under control.
Would be interested to hear others thoughts...

[Moonshyner]

The theory of dropping ph applies more to all grain
All grain has a lot more buffering ability. Being able to hold ph even with low start ph.
Sugar washs ph will drop low fast naturally. Unless you have very hard water(kentucky limestone) you dont need to adjust ph on a sugarhead.

On all grain there is a lot of bacteria on the grain. That causes infection unless ph is low.

But the grain itself adds buffering capability(the bottom wont fall out of ph) the ph will remain fairly stable. Even at low(acidic) start ph.

But if you dont drop the ph you will get infection. Hence the start point of 5.5ish.

An all grain mash will also handle a lot more backset(acid) then a sugarhead.

Just my humble opinion but I think the practice of backset and 25% backset for burbon stem from limestone water of burbon country. Very hard high calcium water. They were getting infections and needed 25% backset to get the infections under control.
Would be interested to hear others thoughts...

I do thank you kindly for the extra info.
So much reading has led me to believe that I needed to have the water at 5.2 PH regardless of type of wash. Maybe I misread something.
I am now a little more knowledgeable.

Cheers,