KOH for boosting pH?

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Toxxyc
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KOH for boosting pH?

Post by Toxxyc »

So I have a stuck fermenting sugar wash. I asked around and came across a few bases I can try but I have a friend at a chems place and he gave me a sample of KOH (Potassium Hydroxide). He mentioned it's the strongest base he has, and it should be perfectly food-safe. I breaks down into potassium and water, apparently, both of which are fine.

Now I know the flakes are dangerous, but I was wondering - has anyone used it to raise the pH in a fermenting wash (or perhaps buffered the wash with it before pitching the yeast)? If so, how much do I use?
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Re: KOH for boosting pH?

Post by Mr Sippy »

That stuff is a nasty caustic. Drain cleaner caustic. Food safe and soluble, yes.

Might consider potassium carbonate instead. For that I use 3 tsp/5 gal.
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Re: KOH for boosting pH?

Post by Hügelwilli »

Toxxyc wrote: Tue Apr 13, 2021 2:29 am So I have a stuck fermenting sugar wash. I asked around and came across a few bases I can try but I have a friend at a chems place and he gave me a sample of KOH (Potassium Hydroxide). He mentioned it's the strongest base he has, and it should be perfectly food-safe. I breaks down into potassium and water, apparently, both of which are fine.
It breaks down almost complete into potassium-ions and hydroxide-ions.
Mr Sippy wrote: Tue Apr 13, 2021 2:56 am Might consider potassium carbonate instead.
This breaks down almost complete into potassium-ions, hydroxide-ions and carbon dioxide.

The hydroxide is pure much more caustic. But diluted the hydroxide is only around 25% stronger than the carbonate.

Very fast changes of the pH are not good for the yeast. So next time try a better recipe which includes a buffer.
This time you can use any base or alkali salt in moderate amounts. If the problem of your wash is really the pH. That this recipe doesn't include a buffer looks like that there are perhaps more problems than the missing buffer.
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Re: KOH for boosting pH?

Post by Toxxyc »

Yes I'm aware of the drastic changes it can bring, but at this point I have a stuffed up situation that I want to fix. And I have the KOH, and it it food safe, so I'll use it on this one. I'll honestly be looking at oyster shells for my next batch, because this one is a headache.

Anyway, considering how strong of a base it is, can I dilute a little bit in water (more water) and then add that? It'll be a lot safer and easier to manage then as well. The flakes are sealed so can't pull moisture where it is, so it's pretty safe right now (for now).
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Re: KOH for boosting pH?

Post by Birrofilo »

When I had a similar problem, I solved it with four eggshells in a 30 litres batch. I ate the eggs, rinsed the shells, took away the inside pellicle, made the shells into little fragments, and put those in the fermenter. Worked a charm. No risks.
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Re: KOH for boosting pH?

Post by zed255 »

Calcium hydroxide is readily available if you need something stronger than calcium carbonate. It is available by different names:

Pickling lime at the grocery store sold for traditional pickle making
Slaked lime or hydrated lime at the building supply store as a concrete additive

I wouldn't be too fussy about something like this being 'food grade' or 'lab grade', as you will be distilling the wash and the amount you'd really need is small. I got a bag inexpensively from my local building supply store and it will be enough for ten lifetimes of distilling.

Be aware that despite CaOH being milder than both KOH and NaOH it can still hurt you in strong solutions and needs some respect. In most cases you can get pH corrected with a carbonate, but if a reasonable amount of a carbonate isn't cutting it moving to a hydroxide may help. Just be advised that a wash that has crashed that hard may be unrecoverable. If that is the case I'd either dump it if it stalled early, run it if it stalled late or try to save the material by adding some as part of a fresh ferment as if it were backseat or dunder. Oh, and whatever you did to result in a stalled ferment, avoid doing that again ;).
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Re: KOH for boosting pH?

Post by still_stirrin »

Potassium is a great yeast nutrient. And KOH is a very strong base, so you wouldn’t need much to raise the pH dramatically. Of course, you’ll need to “handle with care” —> make sure you wear rubber gloves and eye protection and make sure you don’t splash it.

But, diluted with distilled water and then slowly added to the ferment, a little at a time, it would work great. Be careful not to “overshoot” your goal (pH 4.0 - 5.0).

I would much prefer to use potassium hydroxide over sodium hydroxide (lye), although calcium hydroxide is a fair compromise. It is much easier to source and less caustic. And calcium is also a good nutrient for yeast metabolism. I use “pickling lime” (calcium hydroxide) for raising pH if/when necessary. The powder is easy to store and can be rehydrated before adding to an acidic ferment.
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Re: KOH for boosting pH?

Post by StillerBoy »

Toxxyc wrote: Tue Apr 13, 2021 2:29 am So I have a stuck fermenting sugar wash.
The issue with having a stuck sugar wash ferment is lack of research and understanding of what was involved with doing a sugar wash.. then there would of been no need to figure out why the result gave a stuck ferment, and then requiring how to resolve it..

Be on the safe side, and use calcium carbonate or calcium hydroxide as recommended by others, or learn to use sea shells, but they require their own learning curve also..

There is a process and method to doing a wash, as there are many items that required attention to achieve a successful result..

Spend the time to document what is required, tools required, ingredients required, yeast ferment temp, ambient temp, stable ferment temp, Ph at pitching time and at the 9th hr, to name just a few, then develop a process, and implement the process.. that is the only way forward in developing success..

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Toxxyc
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Re: KOH for boosting pH?

Post by Toxxyc »

Oh for sure. I've made a lot of beer before, and I simply underestimated the amount of acidity in a sugar wash. I literally pitched a sugar wash straight onto an old yeast cake, and it bit me in the ass. I won't make that mistake again.

Also, I think I need to get pH strips, or a pH meter or something. I never use it in brewing (because it always works out), but I think in washes it's a lot more fluctuating in range.
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Re: KOH for boosting pH?

Post by NZChris »

That's what I did with my current sugar wash, putting it down using my grape pomace. It started at 6 and has only dropped to 5 on day five. Sometimes they drop a lot quicker and I put a couple of large shells in on day two or three, but not this time. If I had put shells in it, I doubt it would have made much difference to the pH, or the speed of the ferment.

One advantage of using whole shells as a buffer is that it's quite difficult to get the amount used wrong. You only need to do something if the ferment is finished and there is a lot of shell left in the fermenter, and you're not going to run it sometime soon.
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Re: KOH for boosting pH?

Post by Saltbush Bill »

Toxxyc wrote: Tue Apr 13, 2021 10:34 pm I've made a lot of beer before, and I simply underestimated the amount of acidity in a sugar wash.
I sort of shudder every time I see a welcome thread that says ..."Long term beer guy"......or ..."been brewing for years, won beer competitions".
How many beer brewers have ever made cuts? know that you cant drive a still by temp? have had to deal with corn or many of the other grains that distillers use? Most don't know the difference between a reflux and a pot when they arrive here, but by some miracle, making beer will make them better distillers.
Sure if all you ever want to do is mash barley it may help....otherwise not so much.
Not pointing the finger at you personally Tox......just something that Ive noticed over the years.
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Re: KOH for boosting pH?

Post by Toxxyc »

Oh for sure, I fully understand that. I was maybe a poster child for such a problem myself, and I'll happily admit it. I made beer for years, and then decided to build a pressure cooker still about a year ago (maybe a bit less). I figured distillers aren't bothered with sanitisation, they don't really care for recipes, treating their yeast right, they don't cold crash, there's no worrying about fermentation temp (a ballpark is fine), etc. etc. So, and yes, I was this obnoxious, I figured "how hard can it be"?

Well, hard. That's for sure. I've learned A LOT in the past few months, and I'm still going strong on the learning front. This thread was started because I applied beer making logic to a sugar wash - and it didn't work out. When making beer you can pour your chilled wort onto a yeast cake over and over again - the pH doesn't go down too low, almost ever. That's not the case with sugar washes - another lesson learnt.

Also, one thing I must point out, which I'm sure people will pick up here, I'm not somebody to follow rules in the traditional sense, if I can put it that way. So as a stupid example, if you tell me a sugar wash won't work with just sugar and water and yeast, I'll believe you, but I'll still do it myself to make the mistake myself, first and foremost to see what the mistake looks like and also to try and figure out how to fix it. I'm curious, and that's what drew me to distilling in the first place. A bad batch of beer got turned into "meh" whisky that friends loved, and I hated. I learned recently that the hop aroma and flavours pull through the still pretty damn well, so there's another lesson learned - don't expect great white dog from a distilled beer.

Anyway, learning as I go along. It's fun. I like it.
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Re: KOH for boosting pH?

Post by Saltbush Bill »

Toxxyc wrote: Wed Apr 14, 2021 12:50 am Oh for sure, I fully understand that. I was maybe a poster child for such a problem myself, and I'll happily admit it. I made beer for years, and then decided to build a pressure cooker still about a year ago (maybe a bit less). I figured distillers aren't bothered with sanitisation, they don't really care for recipes, treating their yeast right, they don't cold crash, there's no worrying about fermentation temp (a ballpark is fine), etc. etc. So, and yes, I was this obnoxious, I figured "how hard can it be"?
You have nailed it and understood exactly what I meant. That is the problem " the how hard can it be if a bunch of "Hillybillys" can do it" attitude that some folk arrive with.
Ive seen a lot of people come and go from different forums, I think its easier to teach someone to distill who has no prior experience in either hobby than it is to teach a brewer sometimes. Complete newbs don't come with preconceived ideas on all manner of things such as yeast types and hygiene practices.
Toxxyc wrote: Wed Apr 14, 2021 12:50 am Anyway, learning as I go along. It's fun. I like it.
Glad your enjoying the journey :thumbup:
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Re: KOH for boosting pH?

Post by Toxxyc »

Oh for sure. I'll be honest here (since this thread's gone it's course anyway), but my initial stuff on here was pretty, how shall I say, rough. I posted how I wanted to build a pressure cooker still from an old aluminium pressure cooker, and got so much hate I almost had to call the cops for restraining orders.

Well, I still built the still with that same pressure cooker, and it worked really really well for as long as I used it. I knew from the start it wasn't perfect, but it worked and did what I wanted it to (distilling failed beers into white dog and firestarters). That was fun and games but now I upgraded to something proper, which prompted proper washes, which resulted in this problem I'm facing now.

Heh. Fun cycle. I enjoy distilling mostly as it's an "extension" to homebrewing, if I can call it that. I saw it as the next step, and I took it.
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Re: KOH for boosting pH?

Post by Birrofilo »

Toxxyc wrote: Wed Apr 14, 2021 1:25 am I enjoy distilling mostly as it's an "extension" to homebrewing, if I can call it that. I saw it as the next step, and I took it.
I certainly call it a "fatal attraction". But I suppose the attraction works equally well for the winemakers. Many homebrewers and winemakers inevitably end up distilling.

It's two different sets of difficulties. Homebrewing is much more involved and complicated, one must pay attention to many fine details, distilling in comparison it's like a holiday, the manual side is refreshingly simple. But the difficulty of distilling is that it's your nose-mouth appreciation which makes of you a good or bad distiller. You don't make a good beer "with your taste", but you do make a distillate "with your taste" and it's your taste which makes it good or bad, or good or bad for you.

That's why I am beginning with neutrals. Because that seemed to be easier to make and good to begin with (to an extent, it probably is). Making cuts is certainly more art than science. And it intimidates me...
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Re: KOH for boosting pH?

Post by Toxxyc »

I've been told I have a very sharp palette, so tasting the cuts for me is really cool. I love it. It's probably the most fun part of the whole thing for me. Sitting down to see what I have produced. The tiny result of a LOT of fermenting and mixing and whatnot. The fine taste is worth it for me.
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Re: KOH for boosting pH?

Post by Toxxyc »

Ended up tasting this wash after it died down again yesterday. Sharp, acidic and dry, so it did ferment out at the end. Stripped it yesterday and it actually came out just fine. Can't wait to add this to the lot for the spirit run on this rum.
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Re: KOH for boosting pH?

Post by Toxxyc »

OK so KOH. I had it, and made a rum wash the other day. I overshot my gravity and ended up with a 1.112 OG for the wash.

I pitched a VERY cheap local yeast (like ZAR4 for a 20 gram packet, so like 4 packets for 1 USD), and expected the wash to end up around 10% ABV.

Took a gravity reading yesterday and it sat at 1.018. So that yeast ate all the way to 12.5% ABV in 5 days. Only difference between this batch and previous ones was that I continuously fed the wash with KOH during the ferment. I dissolved a few flakes in the hot wash before pitching the yeast, and fed it a few flakes each day until it was done.

KOH seems to work really well. I'm highly impressed.
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Re: KOH for boosting pH?

Post by MartinCash »

You may get a better result if you water down a high-sugar wash so that you end up reducing the potential alcohol. Less off flavours and les bite. I know this is not about KOH, sorry for the OT.
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Re: KOH for boosting pH?

Post by Toxxyc »

Yep I was actually aiming for a 10% wash, but the calculators I used didn't play along, or I misread a scale somewhere. I usually do a 9 to 10% ABV in the final product for rum, and around 8-9% for my whiskies, but eh. It seems to have worked out just fine.
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