Ways to raise/buffer pH in sugar washes

[pope]

I started having an 'aha' moment after a few sluggish/stuck/struggling ferments of sugar washes. I've been working on syrup based agave/tequila and 'whole cane syrup' rum - prior to this all of my beer, wine, cider, ujssm, birdwatchers, molasses rum, panela rum, etc etc batches had fermented just fine, so I just never even look at pH. I've been using superfood/dap/other nutrients but no other mineral additions to address pH. Come to find some of those clean sugar washes really crash and that was fairly common knowledge on the forum, go figure. So, I'm interested in buffering and raising pH along the road that is fermentation, here's what I've gathered so far:

- Shells (oyster shells whole or crushed a la chicken feed store, or just egg shells) are probably the most common buffer on the site
- Calcium Carbonate, the next most common
- Potassium Carbonate, more expensive but more effective
- Calcium Hydroxide, another powerful tool of choice for some, less common but more powerful in my laymen's understanding
- Sodium Hydroxide is a no-go because of the way sodium interacts with fermentation
- 5.2 mash stabilizer (which I use only for beer brewing to much success) has some buffering ability but it won't raise your pH at all once you're in trouble

Finally there is KOH/potassium hydroxide/potash. I couldn't find much about it, but it is potassium, it dissolves much more easily, quickly, and completely than calcium carbonate (the only of the list I've tried so far since I already had some), and it contains potassium not sodium. I have some lying around (no pun intended), didn't want to f-up anything worse by adding it without anyone's 2-cents if they have some to give.

The most helpful snippet of info to me was via Dnderhead who mentioned White Labs' recommendation of 1# potassium carbonate to 1000 gallons of sugar wash, which will pH crash very quickly on its own. The recommendation is to make the addition within the first 12 hours of the ferment. I am guessing this is so that the pH will fall into the 4's or 3's and you can bring it back up and stabilize it, rather than starting by pushing the pH up above the 5's which is undesirable. That's my interpretation at least.

Any sage advice on the topic is welcome!

[StillerBoy]

Now you have a list of potential ingredients usable for Ph buffering, and with some info on their usage..

Here's the low down on what I do with Ph buffering..

Sugar wash.. the Ph will down with in the first 4 - 6 hrs rapidly.. rapidly means, I normally start my wash at the Ph level of 5.5, with the time stated, the Ph will drop to 2.5.. (and it does not matter if you start it at 6.5, if will down rapidly to the same level).. at the 6 hr mark, I check and adjust the Ph back to 4.5 with any of the three most commonly used buffering agents.. potassium carbonate will required about 2 tsp for a 6 gal batch, or calcium carbonate will required about 6 - 7 tsp for a 6 gal, and same amount used for calcium carbonate is required when calcium hydroxide is used.. cost wise they all pan out about the same based on the amount used.. and they all dissolve will in the wash.. as to using oyster shell, will I've not had much success using them, other than grinding them down to almost a powder, and put them in a bag..

Once the Ph has been adjusted at the 6 hr mark, a re-check at the 24 hr mark may or may not required additional adjustment, and if required it will be a small adjustment..

AG mash.. pretty much use the same ingredient and process, and a little less in amount to make the Ph correction..

Mars

[NZChris]

That sounds like a lot a trouble to go to.

For a wash with a history of pH problems, I
weigh some shells, put them in at the start and seldom recheck the pH until it goes dead, at which point it is nearly always finished. I reweigh the shells and record the drop for future reference.

[HDNB]

the only time i have a PH drop is if i start with too high a PH and get an infection. no amount of raising ph has been able to fix one.

as long as i start 5.2 to 5.6 they finish out great.

[Saltbush Bill]

That sounds like a lot a trouble to go to.

Glad i don't need to go through all of that rigamarole every time I put down a wash. Ive never yet owned a Ph meter ..checked PH ..or adjusted PH .
Have had one stuck ferment once out of hundreds of ferments. That one was a kale wash, ....dumped a bit of chicken scratch/ shell grit into iti and away it went again.
People are making it look like you MUST always check and adjust PH , which is completely untrue.......many never have and never do.
It seems to depend on your water quality , how much backset / dunder you use and other factors.
If you look carefully you can see the PH meters in these blokes top pockets.

[bluefish_dist]

I was a big user of calcium carbonate after I found oyster shells too slow to dissolve in my large fermentations. I also found you can buffer the wash by adding a mix of citric acid and calcium carbonate in equal volumes. Since calcium carbonate is not very soluble in water, adding acid dissolves more cc than the water alone. I would add 1-3 cups of each per 125 gallons. So for 5-15 gallon fermentations you are probably looking at tbsp of each. Also by adjusting your mix you will also set your pitch ph to around 5.3-5.2.

[shadylane]

Just guessing
Adding crushed oyster shell will buffer the pH of a fermenting sugar wash.
Then slowly begin to raise the pH after fermenting is done.
On a side note
Ya don't want the wash to have a pH higher than 7 when distilling
Or you will be asking why is my distillate is blue

[HDNB]

Just guessing
Adding crushed oyster shell will buffer the pH of a fermenting sugar wash.
Then slowly begin to raise the pH after fermenting is done.
On a side note
Ya don't want the wash to have a pH higher than 7 when distilling
Or you will be asking why is my distillate is blue

heheh...i had a bit of food grade lye and some low wines that was really acidic...i tossed some in and apparently put in wayyyyy more than i thought and got to 10. turned the low wines blue, didn't even have to distill them!

[cayars]

I really never had to adjust pH of grain mashes once fermenting but do adjust the pH while cooking to get the pH right in the sweet spot for the enzymes.

My Rum/sugar washes are the only thing I have to monitor and adjust. I pitch at 5.25 give or take and allow pH to fall into the low 4s before I'll raise it trying to hold at 4.5 to 4.6 for the duration of the ferment.

I'll use oyster shell in a mesh bag (easy removal) for sugar washes which helps but the first day will normally need assistance to stabilize the pH.

I can't imagine not owning a low cost pH meter these days nor a set of hydrometers. If you want to make hillbilly shine out in the woods, that's one thing but if you want to make a good base for a Bourbon, Rye or Single Malt it's quite another thing. My grandfather used to ride a horse to work but I'd rather sit in a nice AC/heated car out of the elements driving to work given a choice. I'm sure the old timers would love to have the technology we have today as well given a choice.

[pope]

I'm sure the old timers used grains and molasses and never had problems - I never did 'til I started trying to make tequila and rum with terpenes, 'unfiltered black' agave syrup, 'whole cane syrup' etc - I have found the price to pay for pushing the envelope in my shop and it is pH issues.

I'm gonna try the Potassium Hydroxide on my next sugar wash and just start small, go by weight. Am I being too precise? Probably. But fussing with stuff is the most fun part of the whole hobby for me.

[NZChris]

If you look hard enough, I'm sure you will be able to find something even more difficult, time consuming and expensive than you have found so far.

[kimbodious]

I use crushed shell that they sell as “shell grit” in rural supplies store. 1/4 cup of the grit for each 24 litre fermenter pail. My ferments start less explosively and finish a day or so earlier.

[Desvio]

Over many years I have really had no issues with pH, and the few times I thought there was a problem I quickly bought all the goods only to find out the pH was fine... What I really needed was neuts for the poor little yeasies.

Needless to say I now have pH strips, citric acid and bag of crushed oyster shells with a mesh bag to suspend them in on hand.



[knock on wood]

[DAD300]

Marble rocks, as in from Big Box lawn dept. $3usd for a 50lb bag. Hung in a perforated bottle.

That bottle was half full before a week in a 170 gallon ferment.

Ferment only eats what it needs, no cleanup when removed. Rinse bottle go to next ferment.

[bluefish_dist]

I found ph was critical for non grain fermentations depending on water. Scaling up pointed out my problems. 15 gallon fermentations on well water were fine, 125 gallon on city water were not. It is worth the time to track ph and see how it affects your fermentation.

Doing all grain, it’s not nearly the same issue as sugar or agave. Crushed shells work ok for small fermentations, but i found they do not dissolve fast enough as volume gets larger. Also if you have water with high dissolved calcium, you will have a lot less issue. I never got into full water analysis, but I think it is one place distillers could learn from beer brewers.

[doctee]

I have been using potassium bicarbonate (KHCO3) to buffer the pH in a sugar wash, following Clayton Cones Method #1. I add 3 equal doses the first 3 days of the ferment. ~2.22g/gal for each dose in a 1.092 wash. I was low on KHCO3 after the first dose. I had some calcium carbonate (CaCO3) but did not know the dose rate.

This thread was the most useful I found to compare the efficacy of potassium bicarbonate (KHCO3) .vs. calcium carbonate (CaCO3) to buffer the pH in a sugar wash, but missed the mark on a definitive answer.

So I did some figuring of my own and here is what I found.

KHCO3 can take one H+ (acid) ion whereas CaCO3 can take two H+ ions. By coincidence they have the same molar mass of 100, so I figured that I should use half the grams of CaCO3 that I use of KHCO3 and that is what I tried, ~1.11g/gal for the each dose. Since I ferment a batch in two 6 gal buckets, I could do a side-by-side comparison of the 2nd addition. I used pH papers with a 0.5 resolution for the test. The results are below.

2 buckets. Each with 4.5 gal of 1.092 SG

Day 1 - 10g KHCO3 in #1 and 10g KHCO3 in #2
Day 2 - pH before dose: <3.0 in #1 and <3.0 in #2
Day 2 - 10g KHCO3 in #1 and 5g CaCO3 in #2
Day 2 - pH after dose: ~4.5 in #1 and ~4.5 in #2
Day 3 - pH before dose: ~3.5 in #1 and ~3.5 in #2
Day 3 - 5g CaCO3 in #1 and 5g CaCO3 in #2
Day 3 - pH after dose: ~4.5 in #1 and ~4.5 in #2
Day 4 - will update tomorrow...when its day 4

Conclusion: Day 2 pH measurement after dosing showed that 1/2 the weight of CaCO has the same efficacy as 1 of KHCO3!
It should be noted that CaCO3 is not very soluble in water but will in an acidic solution, so it probably works a bit slower. This may be a good thing.

[bluefish_dist]

As you found out calcium carbonate is not very soluble in water. If you add citric acid and cc, you can get more to dissolve and add buffering to the wash. Ie the initial ph drop will be much lower or none at all. IMHO not always a good thing. Oyster shells and cc are essentially the same thing the difference is how fast they dissolve in acid. Shells are slower as the surface are is much smaller than the typical cc powder.

[StillerBoy]

A few issues with the test done.. one.. the use of Ph paper instead of a meter.. two.. no mention what the Ph of fermentation was at start before pitching.. the acidity level at the start of the fermentation process has an importance to the process..

From experimenting and experience, stabilizing the acidity level at the 6th and 12 hr of the fermentation process with giving you much better results.. how/why.. the fermentation is done much faster, with no issues with the finished product..

Mars