PH drop during fermentation

[PalCabral]

Hiya.

Lately when I have been doing suger washes or sugar heads I have several times gotten quite a drop of PH which halts the fermentation. I get it back on the road again by adding bicarbonate but I really don't know why this is happening. Last time was an AG mash mixed with 2 liters of inverted sugar. The fermentation started out fine and I measured PH after 5 days and the PH was 4.5. 2 days later, the ferment is stuck and the PH lower than 3.8, which is as far as my PH strips go. Same thing happened a few weeks earlier with an all sugar wash. I added a tbsp of bicarbonate and off it goes. I haven't got a clue what makes it drop like this?

The mash was 25L and I added the following nutrients: Boiled bakers yeast, 2 tsp DAP, Epsom salt 1/2 tsp, Wyeast nutrients 1/2 tsp, Chalk 1/2 tsp. The inverted sugar was made with a couple of tsps of citric acid. The water PH in my area is 8. Temperature in the brew house is 22C.

I am thinking I need to up the chalk next time, but I am open for suggestions.

[shadylane]

Fermentation naturally drops the pH and a sugar wash has little or no buffering to stop it from happening.
Put a cup full or 2 of crushed oyster shell in a sock, tie a string to it and suspend it just off the bottom of the fermenter.

[PalCabral]

If I hadn't read several posts on the forum about oyster shells I would have believed you were pulling my leg. Thanks for the tip, I need to read up on what it does and if I can find it here.

[Reefer1]

Shady is right that works, I started using oyster shell, and my ph stays around 4 + not had a stall since.
Also I stopped using RO water for the wash/mash I just use airated tap water, as it has the mineral content.
I got my shell from a local garden centre, it was for adding to chicken feed. I got some nylon bags off of Amazon, failing that Rob you girls tights lol

[Salt Must Flow]

You can buy 40lbs of Marble Rock at Lowes for $6.

I can find 50lbs of Oyster Shell at TSC for $17 or 5lbs for $8.

I prefer Marble Rocks because it's cheaper per lb, nowhere near as fine and doesn't require a really fine mesh bag which restricts access to it. Oyster shell seems to compact relatively tight restricting access where marble rock has gaps between each which allows free access to it. After fermentation is complete, I just remove the bag, hose it off and set it out to dry.

[howie]

Hiya.

Lately when I have been doing suger washes or sugar heads I have several times gotten quite a drop of PH which halts the fermentation. I get it back on the road again by adding bicarbonate but I really don't know why this is happening. Last time was an AG mash mixed with 2 liters of inverted sugar. The fermentation started out fine and I measured PH after 5 days and the PH was 4.5. 2 days later, the ferment is stuck and the PH lower than 3.8, which is as far as my PH strips go. Same thing happened a few weeks earlier with an all sugar wash. I added a tbsp of bicarbonate and off it goes. I haven't got a clue what makes it drop like this?

The mash was 25L and I added the following nutrients: Boiled bakers yeast, 2 tsp DAP, Epsom salt 1/2 tsp, Wyeast nutrients 1/2 tsp, Chalk 1/2 tsp. The inverted sugar was made with a couple of tsps of citric acid. The water PH in my area is 8. Temperature in the brew house is 22C.

I am thinking I need to up the chalk next time, but I am open for suggestions.

what is your starting PH, just before you do the final step and add the yeast?
this is probably the time you should be adjusting the PH and not using so much citric acid.
what is the PH of your inverted sugar after 2 tsps of citric? (2 tspns = 9 -10 grams?)
according to my notes, 2gms of citric can drop 25L by 1 - 1.5 x PH points.
my water is PH 8, i filter the chlorine out and after adding everything to an FFV the PH has already dropped to about 7.
also, i only drop the PH to about 5.7 - 6.0, never had a sugar wash stall in hundreds of brews.
22°C is on the low side, my brew fridge is set to 30°C, bakers yeast can handle 30°C easy.
FFV gets a pinch of epsom & DAP only, and a bloody good aeration with the paint stirrer to ensure a good start.
i do not blindly follow any recipes instructions on adding anything that affects PH, i test first, then adjust.

[PalCabral]

Howie, if I remember correctly, the wash was sitting at a PH of 5.2 before pitching the yeast. I believe you are right that the culprit most likely was the citric acid in the inversted sugar.

I am more concerned for a similar scenario with my upcoming AG brewing for Bourbon, using flaked corn, wheat malt, wheat crystal malt and barley malt, no sugar. I will be adjusting my mash water with 4gr CACO3 (chalk) but I am not sure if this is enough? What should be s good PH when I pitch the yeast, 5.4-5.5, right?

[PalCabral]

Shady is right that works, I started using oyster shell, and my ph stays around 4 + not had a stall since.
Also I stopped using RO water for the wash/mash I just use airated tap water, as it has the mineral content.
I got my shell from a local garden centre, it was for adding to chicken feed. I got some nylon bags off of Amazon, failing that Rob you girls tights lol

Fermentation naturally drops the pH and a sugar wash has little or no buffering to stop it from happening.
Put a cup full or 2 of crushed oyster shell in a sock, tie a string to it and suspend it just off the bottom of the fermenter.

I found clam/mussels shells for chicken in the feedstore, I guess this must be the same? Oysters are not that common this far north but mussels are plentiful. 15kgs was the smallest I could find - 13USD. Will 15 kgs last me a life time? My wife's most common phrase these days is "more shit?". I do have hops bags from my brewing days, I would assume these will work just fine. I promised my wife that I stop wearing tights when we got married...

But I am skeptical about just putting "gravel" into a mash that is going to be fermented by a living organism that isn't a chicken - how do I know there's not all kinds of nasty "stuff" in mix? Do you rinse the crap out of this before using it, do you boil it too? Chicken aren't too fuzzy about what they eat, saccharomyces is.

I prefer Marble Rocks because it's cheaper per lb, nowhere near as fine and doesn't require a really fine mesh bag which restricts access to it. Oyster shell seems to compact relatively tight restricting access where marble rock has gaps between each which allows free access to it. After fermentation is complete, I just remove the bag, hose it off and set it out to dry.

Lowes is not granting me access to their site - what do they know about me that I don't?

But how do you prep the rocks, Salt? Do you boil them first, or just rinse? How long do they last? If they make any difference they will be giving away salts to the fermentation and thus slowly diminish in size. Rocks become pebbles that become gravel?

[MooseMan]

Shady is right that works, I started using oyster shell, and my ph stays around 4 + not had a stall since.
Also I stopped using RO water for the wash/mash I just use airated tap water, as it has the mineral content.
I got my shell from a local garden centre, it was for adding to chicken feed. I got some nylon bags off of Amazon, failing that Rob you girls tights lol

Fermentation naturally drops the pH and a sugar wash has little or no buffering to stop it from happening.
Put a cup full or 2 of crushed oyster shell in a sock, tie a string to it and suspend it just off the bottom of the fermenter.

I found clam/mussels shells for chicken in the feedstore, I guess this must be the same? Oysters are not that common this far north but mussels are plentiful. 15kgs was the smallest I could find - 13USD. Will 15 kgs last me a life time? My wife's most common phrase these days is "more shit?". I do have hops bags from my brewing days, I would assume these will work just fine. I promised my wife that I stop wearing tights when we got married...

But I am skeptical about just putting "gravel" into a mash that is going to be fermented by a living organism that isn't a chicken - how do I know there's not all kinds of nasty "stuff" in mix? Do you rinse the crap out of this before using it, do you boil it too? Chicken aren't too fuzzy about what they eat, saccharomyces is.

I prefer Marble Rocks because it's cheaper per lb, nowhere near as fine and doesn't require a really fine mesh bag which restricts access to it. Oyster shell seems to compact relatively tight restricting access where marble rock has gaps between each which allows free access to it. After fermentation is complete, I just remove the bag, hose it off and set it out to dry.

Lowes is not granting me access to their site - what do they know about me that I don't?

But how do you prep the rocks, Salt? Do you boil them first, or just rinse? How long do they last? If they make any difference they will be giving away salts to the fermentation and thus slowly diminish in size. Rocks become pebbles that become gravel?

Your clam/mussel shells will be fine for the job, any source of CC will do it so get the cheapest.

I was also worried about bugs and nasties, so when I collected my shells from the beach I gave them a few shakes with boiling water in a bucket, then rinsed with a sanitiser and dried in the sun.

But for clarification, you absolutely do not need any pH buffer in a grain ferment as the grain with handle that fine. You'll have no pH issues at all.

[higgins]

...
But for clarification, you absolutely do not need any pH buffer in a grain ferment as the grain with handle that fine. You'll have no pH issues at all.

MooseMan, I have to disagree with you on this. If I'm using a grain bill with a significant amount of dark grains I have to add buffering capacity to my water or the pH will drop too low. IMO it is important to know the composition of your water and how to adjust it when necessary.

Everyone's water is different, and different mineral contents will create different mash conditions. It is mostly about alkalinity - the ability to resist change in pH. Roasted and Toasted grains are more acidic, and will lower the pH unless there is a fair amount of alkalinity.

I have brewed AG beer since 1997, roughly 10 batches, 75-100 gallons per year up until about 5 years ago. When I first started with all-grain I found that my lighter colored beers had a rather bland character, but my darker beers were bright and crisp. So digging into it I learned that dark grains tend to lower pH much more than light grains, and with my water (hardness 160, alkalinity 118) that meant dark beers mashed at the right pH, but light beers mashed at higher pH. I learned to make lighter beers that tasted much better after learning how to treat my water, mainly using Gypsum (Calcium Sulfate) to acidify the mash.

So when I retired and move up into the mountains 10 years ago I had the opposite problem ... light beers were good, but dark beers were muddy. My water here has similar hardness almost no alkalinity (hardness 144, alkalinity 17), so when I mashed a batch of dark beer the pH would drop below 5. Now for dark beers I have to add some Calcium Carbonate to buffer the change and keep the pH of the mash in the 5.2-5.6 range.

[howie]

mooseman and higgins are both correct in a way, but it's getting technical.
yes, dark grains will need some PH attention but most grain bills are perfectly fine, like the one palcabral is using.
15kg of chicken grit will probably last a liftime though

[PalCabral]

Your clam/mussel shells will be fine for the job, any source of CC will do it so get the cheapest.

I was also worried about bugs and nasties, so when I collected my shells from the beach I gave them a few shakes with boiling water in a bucket, then rinsed with a sanitiser and dried in the sun.

But for clarification, you absolutely do not need any pH buffer in a grain ferment as the grain with handle that fine. You'll have no pH issues at all.

Thanks for the reassurment, Moose. I will try the shells and see how it works out.

MooseMan, I have to disagree with you on this. If I'm using a grain bill with a significant amount of dark grains I have to add buffering capacity to my water or the pH will drop too low. IMO it is important to know the composition of your water and how to adjust it when necessary.

You are correct about this, Higgins. Darker malts, roasted grains, will drive down the PH - as an old brewer I know this well. Luckily, the malts and grains we tend to use in distilling are lighter. For my upcoming Bourbon I will use 4% crystal malt, so a fairly small amount.

[Salt Must Flow]

I prefer Marble Rocks because it's cheaper per lb, nowhere near as fine and doesn't require a really fine mesh bag which restricts access to it. Oyster shell seems to compact relatively tight restricting access where marble rock has gaps between each which allows free access to it. After fermentation is complete, I just remove the bag, hose it off and set it out to dry.

Lowes is not granting me access to their site - what do they know about me that I don't?

But how do you prep the rocks, Salt? Do you boil them first, or just rinse? How long do they last? If they make any difference they will be giving away salts to the fermentation and thus slowly diminish in size. Rocks become pebbles that become gravel?

I just rinsed them well and they're good to go. Boiling is not necessary. It will last a very long time because each piece is larger than crushed oyster shell. Yes, it dissolves as needed to buffer the PH. I prefer it because it's less expensive, readily available (garden section at Lowes), it's not really fine like shell and you can use a coarse net bag to hold it. I have always suspended the bag approx 1/2 way into the fermenter. After fermentation, I remove the bag, rinse it off and set it out to dry.

[shadylane]

I prefer using the crushed shell for chickens as it comes out of the bag. No washing or any attempts at pasteurizing it.
On a fast fermenting sugar wash the pH drops quickly, the fines get used on the first day or two.
The coarser parts are then available if or when needed.

Other folks mileage may vary. It all depends on the water being used to ferment a sugar wash.
I prefer to have more buffering early, that requires some of the calcium carbonate to be as fine as dust.

[Turbo6ta]

To increase the pH in the neutral sugar wash I will be making for gin, I just purchased some cacium carbonate to keep the pH between 4.5 and 5.5 during the fermentation.

From everything I have read, a 4.5-5.5 pH is just about right for a sugar wash.

Correct me if I'm wrong

[howie]

To increase the pH in the neutral sugar wash I will be making for gin, I just purchased some cacium carbonate to keep the pH between 4.5 and 5.5 during the fermentation.

From everything I have read, a 4.5-5.5 pH is just about right for a sugar wash.

Correct me if I'm wrong

what kind of sugar wash?
personally i've done hundreds of FFV washes and never used any buffer,shells or CC & never had one stall.
maybe i'm lucky, maybe i follow all the basic techniques.
i adjust my FFV's in the 5.5 - 5.9 range for pitching.
i've measured the PH dropping 0.5 and up to 1.0 in the first 2/3 days of a sugar wash.
i figure that the natural PH drop takes my wash from a slightly high PH into a good PH range for fermentation.
<dons tin hat>

[Salt Must Flow]

To increase the pH in the neutral sugar wash I will be making for gin, I just purchased some cacium carbonate to keep the pH between 4.5 and 5.5 during the fermentation.

From everything I have read, a 4.5-5.5 pH is just about right for a sugar wash.

Correct me if I'm wrong

You can use Citric Acid to 'lower' the starting ph of a sugar wash to 5.2 -5.6. Pitch yeast, suspend a bag containing a source of Calcium Carbonate in the wash and it will 'buffer' the ph throughout fermentation. After fermentation the ph should be around 4.

[PalCabral]

what kind of sugar wash?
personally i've done hundreds of FFV washes and never used any buffer,shells or CC & never had one stall.
maybe i'm lucky, maybe i follow all the basic techniques.
i adjust my FFV's in the 5.5 - 5.9 range for pitching.
i've measured the PH dropping 0.5 and up to 1.0 in the first 2/3 days of a sugar wash.
i figure that the natural PH drop takes my wash from a slightly high PH into a good PH range for fermentation.
<dons tin hat>

Howie, not sure I follow. You say you adjust your FFV in the right PH range before pitching, but you never used CC or shells. So how are you adjusting it? Maybe I’m thick?

[SW_Shiner]

what kind of sugar wash?
personally i've done hundreds of FFV washes and never used any buffer,shells or CC & never had one stall.
maybe i'm lucky, maybe i follow all the basic techniques.
i adjust my FFV's in the 5.5 - 5.9 range for pitching.
i've measured the PH dropping 0.5 and up to 1.0 in the first 2/3 days of a sugar wash.
i figure that the natural PH drop takes my wash from a slightly high PH into a good PH range for fermentation.
<dons tin hat>

Howie, not sure I follow. You say you adjust your FFV in the right PH range before pitching, but you never used CC or shells. So how are you adjusting it? Maybe I’m thick?

I would hazard a guess that hes using an acid to lower the pH to desired range then letting the ferment run its course.

[SW_Shiner]

what kind of sugar wash?
personally i've done hundreds of FFV washes and never used any buffer,shells or CC & never had one stall.
maybe i'm lucky, maybe i follow all the basic techniques.
i adjust my FFV's in the 5.5 - 5.9 range for pitching.
i've measured the PH dropping 0.5 and up to 1.0 in the first 2/3 days of a sugar wash.
i figure that the natural PH drop takes my wash from a slightly high PH into a good PH range for fermentation.
<dons tin hat>

Howie, not sure I follow. You say you adjust your FFV in the right PH range before pitching, but you never used CC or shells. So how are you adjusting it? Maybe I’m thick?

I would hazard a guess that hes using an acid to lower the pH to desired range then letting the ferment run its course. I also have not used any buffer in any washes.

[PalCabral]

You are right. That makes sense. However, for me that’s not going to work. Lowering the PH is why I got stuck fermentation. I need to get the PH to stay up.

[NZChris]

If the pH is a bit over the high end of the desired range, I don't do anything. It will drop soon after the pitch.

[shadylane]

To increase the pH in the neutral sugar wash I will be making for gin, I just purchased some cacium carbonate to keep the pH between 4.5 and 5.5 during the fermentation.

From everything I have read, a 4.5-5.5 pH is just about right for a sugar wash.

Correct me if I'm wrong

For a sugar wash, not getting too far below 4.0 ish is good enough.
Yeast is bull frog tough.

[shadylane]

You are right. That makes sense. However, for me that’s not going to work. Lowering the PH is why I got stuck fermentation. I need to get the PH to stay up.

My thoughts on using acid to drop the pH of a sugar wash before pitching yeast.
Bad idea, unless something that's base is also used to make a buffer.
pH crashes were common back in the days when folks were unnecessarily using acid to invert sugar.

[howie]

what kind of sugar wash?
personally i've done hundreds of FFV washes and never used any buffer,shells or CC & never had one stall.
maybe i'm lucky, maybe i follow all the basic techniques.
i adjust my FFV's in the 5.5 - 5.9 range for pitching.
i've measured the PH dropping 0.5 and up to 1.0 in the first 2/3 days of a sugar wash.
i figure that the natural PH drop takes my wash from a slightly high PH into a good PH range for fermentation.
<dons tin hat>

Howie, not sure I follow. You say you adjust your FFV in the right PH range before pitching, but you never used CC or shells. So how are you adjusting it? Maybe I’m thick?

my basic town water after filtering is PH 8, that is obviously too high.
so i adjust the PH down using citric for FFV.
the last FFV was 5.7 before i pitched, it probably dipped to 4.7 during fermentation so there is no need for any more chemicals.
but like someone else has said, you don't want your PH dropping below 4 if possible, so pitching at 4.5 is risky imho.
a couple of tests i did, the PH will usually drop in the first 2/3 days then stabilise.

FFV is bullet proof, bakers (lowans) yeast plus its favourite food (sugar) + DAP and epsom, in a lovely bath of aerated 30°C water (PH adjusted) in a temp controlled fridge.
WTF can go wrong?

[shadylane]

Why adjust the pH downwards on a sugar wash?
Yeast will do that naturally while fermenting, what's needed is to limit the pH from dropping to far.
Adding acid just makes the problem worst. Instead add something that's base and let the fermentation make it's own buffer.
The 5 - 5.5 pH is needed for malt to sugar conversion, this adjustment isn't necessary for a sugar wash.
It just make the wash more likely to crash.

[bilgriss]

+1 Shady. There's no reason to lower a sugar wash pH. It will do it on its own.

pH becomes important when mashing grains, as if it is too high, enzymes don't work as well. But the goal is never to lower it for the sake of fermentation; that happens naturally. And it's not a bad thing, provided it doesn't plummet. The lower pH keeps other things from growing in your ferment. Just can't go TOO low, or it also keeps the yeast from doing their job.

[Reefer1]

It's some good discussion on ph guys.
I think it's a personal experience main thing I get from this is knowing what your ph water supply is so you can make a informed decision on buffers, my supply is 6.5
I have had quite a few washes stall I have added calcium chloride, bicarbs in the past but a bag of oyster shell seemed to be the best suspended in the bucket from the go surely belt and braces, if the wash needs more buffer it dissolves the shell as needed, that's my experience with my supply.

[NZChris]

I don't check the pH of the water, only checking the wash pH after it's been put together and is ready for the yeast. It seldom gets adjusted. If it's high, I leave the shells out until it starts to drop, usually the next day.