Addition of DAP and Citric Acid Stopped Fermentation?

[tboneq121]

Last night I started fermenting 6 3 gallon batches. 4lbs sugar, 3 gallons water, cup of Gerber, 1/4 cup yeast, tblsp of lemon juice and a pinch of Epsom salt. Everything was chugging along.

Today I went to the supply store to get a hydrometer and I went ahead and bought a couple jars of DAP and citric acid. As I was pulling samples and measuring I went ahead and added 1 tsp of DAP and 1 tsp of citric dissolved in water as per Wineo's sugar wash but I had forgotten to halve those as I had split the recipe up into halves. Now 3 of my 6 airlocks are showing almost no activity after being very active. The other three haven't missed a beat.

Did I kill the yeast, is this salvageable, what do you think happend etc. ? After about 12 hours of fermenting the gravities were sitting at at 1.015 on one batch and the rest right around 1.020 if that helps.

[rad14701]

It's a pity that you thought you had to fuss with washes that were 2/3 - 3/4 fermented... You need to learn to sit on your hands and not mess with washes that aren't having problems... It could have been the citric messing with the pH or something in the DAP... Without knowing which was the culprit it's tough to say what might fix the problem... A bit more Gerber would have been more helpful than either the citric acid or DAP... The wash wash already acclimated to the Gerber and it has virtually everything the yeast needs...

[Dnderhead]

you mite have lowered the PH to much adding both lemon juice and citric acid.

[tboneq121]

We'll see...2 of three stuck ones have started to show a little life and the last one is building gas it seems as the air bubble grows larger in the airlock line. So, hopefully the yeast is rallying.

[tboneq121]

Alright, everything basically came to a stop airlock wise. But... I went ahead and checked the gravity on the top two beer batches and they have dropped from 1.020 to a little under 1.010 in the past 12 hours. I'm not sure but would this setup for an airlock allow heavier c02 to concentrate in that octopus of tubing and not show any action in the bottle bubble wise? When I pulled a sample I was still seeing activity in the buckets. Would I be better off cutting the tubing to the shortest length I can? Sorry for the hand holding but I'm working on my second run!


002 by TyMoe, on Flickr

[Pop Skull]

From my winemaking classes - you're best off adding nutrients and such during the growth phase of your yeast - before the alcohol concentration starts rising. At that point the yeast can assimilate what you've added - later on the alcohol makes their cell walls leaky, so that they're spending most of their energy pumping H+ ions out of the cellular interiors to concentrate much on importing nutrients.

If you think you're going to need DAP, probably add half of it 12 hours or a day after innoculation, and then add the second half before your yeast have consumed the first third of the available sugars.

That's what I learned for wines - I suppose your milage may vary for preparing a mash.

If you're still having ttrouble with the ferments - I guess it would be a good idea to check your pH - see if you're in your yeasts happy place or not. I suppose if you're pH is not idea you could try and titrate backwards with sodium bicarbonate (K2CO3 is probably better option, as K+ can help buffer your solution to a higher pH). Or a dilution of your mash and reinoculation with a more vigorous yeast strain - I think EC1188 might be good.

[Dnderhead]

your SG has dropped so it is working,most likely you have a air leek.

[lumberped]

This is a bit late I know , but I just read your post , and looked at your setup. Keep in mind that I am at best a novice distiller , and this is just my humble opinion.

It seems that you have quite a bit of tubing for the gas to pass thru in order to get to your airlock.

The small amount of pressure generated by the fermentation in the later stages , may make it difficult , if not impossible for the gases to make the trip to the airlock---- path of least resistance and all.
You may be better suited to cut you tubing , and form 6 small bubblers(airlocks) than to try to use one central one.

My fermenters are identical to yours with the exception of the airlocks.
I used small prescription pill bottles( no inferences please) - the type with the snap-on lid.
Each airlock consisted of the bottle with a hole just the right size to allow a tight fit of the hose without air leaks to penetrate the lid.
In addition to that hole , I made a smaller hole , perhaps 1 mm in diameter to allow the offgases to escape the bottle.
As long as your hose remains submerged in the water you have a working vapor lock.
The length of tubing allowed for the medicine bottle to rest at the edge of the fermenter in a vertical position , so as to not allow the water to spill.
Works great for me , and I have no trouble with the gases becoming backed up in the fermenter and potentially doing harm to my mash.

Again , I am a humble novice, and this is just my opinion, and what works for me. But , I will say if you use my rigs, you will have alot of extra tubing left over to go toward making additional fermenters


Lumberped