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PH adjustments. Which chemicals are best?

Specifically I need an answer on PH increases (base). I’m using sodium bicarbonate because we can get it here cheap and easy. I’m wondering what effect it might have on my wash and final product? Is calcium carbonate better? Are there other options to increase PH?




  • edited May 2019

    Food grade lye - sodium hydroxide.

    Very effective at small volume additions - the downside is addition of sodium which might cause yeast stress if your mash water is naturally high in sodium.

    Far more effective than carb/bicarbonate - and sodium bicarbonate has an even bigger sodium problem.

    This is not the hobby/diy option as you are dealing with serious caustics.

  • We have 2 pH-increasing processes, and we use 2 different bases for 2 different reasons. Our still effluent is typically too acidic to be used as irrigation/fertilizer as is, so we adjust the pH from typically 3.5-4.5 to about 6.5 using sodium hydroxide, lye, a very serious base, because we have a large amount of acid to neutralize. It's super for this need, and the only added material is a little bit of sodium,

    To lower the pH of the wash we put in the vodka still, for the purpose of driving the esterification equation away from ester formation, we use a small amount of sodium carbonate. Compared to sodium BIcarbonate, the carbonate will react with twice as much acid as the bicarbonate, and it's safe and easy to use.

    If it needs saying the lye takes some serious safety process.

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • @zymurgybob so you use sodium carbonate to lower PH. As a matter of interest, what are you using in fermentation to raise PH.

  • edited May 2019

    Um, we use sodium carbonate to raise pH.

    Although I've had some oddball (with respect to pH) ferments in the past, our barley malt, sugar (a TPW called the MUM wash), or the grape pomace ferments for grappa all know exactly what pH to be, and they just do it without my having to tell them.

    The early exception I referred to was a combination barley malt/sugar wash with a pH that took off for the basement as soon as it started, and ate any carbonate I threw at it, even clam and oyster shells like candy. Nasty stuff. We never solved it, and now just do those ferments separately.

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • What about calcium carbonate?

    The whole sodium/yeast stress thing might be an issue for me. We are adding close to 250g of sodium bicarbonate per 200l wash over the course of the ferment. We have naturally soft water here too.

  • Potassium hydroxide KOH has the same effect as sodium hydroxide NaOH without the sodium load (potassium instead)

    Be aware - both KOH and NaOH are very dangerous to work with. Use of PPE is imperative. Eye protection and gloves are minimum PPE. A face shield and apron are also a very good idea.

    One splash of KOH or NaOH in the eyes will cause severe eye damage. Splashed on the skin, you may not notice it right away. By the time you feel it much damage has been done.

    That said, KOH is my fermentation pH raiser of choice. A little dab'l do ya.

    I use NaOH to make soap.

    I'm more like I am now than I was before.

  • So yeah. Gypsum? Chalk? I work with relatively unsophisticated workers. Lye might not be the best option.

  • edited May 2019

    You can add buffers to the wash pre-fermentation in an attempt to slow or prohibit the pH drop - this is why hard water is far superior for fermentations destined for distillation. If this is the goal, you really need to start with a water analysis first, and build back your water to target - this is to understand where the other important ions are, like sodium, sulfates, etc etc.

    However, this is very different from adding a base like sodium hydroxide to correct pH. You'll require a significant amount of carb/bicarb to raise pH if you've already dropped, and to know the right amount to add before hand - becomes very much trial and error. Usually the amount needed to stop pH drop in something like a white sugar wash is astronomical, and getting it to dissolve is not trivial.

    This is where lye (sodium or potassium) is superior, you require far smaller additions to make pH corrections. However, like @Kapea says - it's dangerous to work with, safety is required.

    Pellet or granulated KOH might be an easier option - especially if you pre-measure and package (air tight) small quantities for one-time use. Full protection is still required here, but you aren't dealing with liquids.

  • My water situation is gonna be difficult. It’s city water and requires chlorine neutralization at a minimum. We are using sodium thiosulfate.

    Then it’s naturally soft anyway so I’ll have to get an analysis and see where everything is at chemically.

    Then I add some citric and sodium bicarbonate to buffer before adding sugar. Then after additions are made and before yeast, I balance ph to 5-5.5. Usually at this point I’ve got 100g of sodium bicarbonate.

    Then after the initial crash on day two or three I’ll add another 100g sodium bicarbonate.

    Then each day I’ll add more to keep it at the desire level. Usually a diminishing amount like 100, 50, 25. All said by completion I’ve added 20g of sodium thiosulfate and 250g+ of sodium bicarbonate to a 200l wash.

    That just seems like it’s enough sodium to maybe cause some issues or off flavors.

    We may be able to try KOH but food grade might be a issue. We make soap too so I’ll see what the girls are using and if I can try it.

    My original (unasked) question was sodium bicarbonate or calcium carbonate... which is better and what are the drawbacks?

    What are the issues with calcium?

  • Calcium carbonate is not very soluble in water, so if you add a large quantity, it will settle at the bottom and do nothing. If your water is acidic and contains lots of co2, more will dissolve. This is why you hear of people using sea shells added to a ferment.

    Sodium bicarbonate is significantly more soluble in water.

  • And I thought you were pulling the piss with sea shells :)

  • Sea shells and coral I can get. Been thinking of trying this but been lazy to hit the beach with a sack and a bad attitude so I could collect them.

    Also apparently we have some sodium hydroxide on hand. I have no idea how to tell if it’s safe for use in fermentations tho.

  • Here’s the bag


    600 x 800 - 69K
  • edited May 2019

    That's pure enough for use in fermentation bound for distillation. I don't see a commonly used grade on that, FCC, USP, ACS, Reagent - but greater than 99% purity is going to put it into ACS grade, which is more than good enough. ACS and USP are American designations, but widely used, so not surprised they might not appear.

    While 99% would typically be considered good enough for food grade, that designation has more to do with the nature of the less-than-one-percent of contaminants - arsenic, lead, etc.

  • edited May 2019

    @richard said: And I thought you were pulling the piss with sea shells :)

    I first heard about using seashells from the New Zealanders, and we were having huge problems with a hybrid wash acidity. Conveniently, we have saltwater and shells within 100 feet of the distillery.

    Shells couldn't catch up on low pH once the wash had gone acidic, but when introduced when the wash was made up, it worked pretty well. You can actually observe loss of shell mass.

    A warning: Never use a shell that has any remaining organic material on it. Fermented clam will never be a popular flavor!

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • I dunno about that, if you had ever seen my Swedish girlfriend swallow rollmops you may disagree.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • Well shells and coral fit nicely with the story of being “of Fiji”, so, Here we go...

    Also sodium hydroxide preps to be made today!

    Thank you all for your advice and input. It has been reviewed several times and taken to heart! @grim @zymurgybob @Kapea

  • ANY idea how much lye I’ll need to raise ph by half a point in a 200l wash?

    It would take about 75g if S bicarbonate

  • edited May 2019

    @Fiji_Spirits said: ANY idea how much lye I’ll need to raise ph by half a point in a 200l wash?

    It would take about 75g if S bicarbonate

    That would depend on your starting point pH, and where you want to get to:

    I dont think my yeast is having enough babies:

    @Kapea said: The pH scale is logarithmic (it represents the negative log of the hydrogen ion concentration in the solution).

    What this means is a pH6 is 10x more acidic than pH7
    pH5 is 10x more acidic than pH6 (100x more than pH7)
    pH4 is 10x more acidic than pH5 (100x more acidic than pH6, 1000x more acidic than pH7)

    Therefore the amount of acid needed to lower your pH increases as the pH of your wash decreases.

    The same thing applies when adding base to your wash to raise your wash's pH
    To raise your pH from pH3 to pH4 requires 10x more base than raising the pH from pH4 to pH5 (etc.)

    I'm more like I am now than I was before.

  • I add 1/4 cup of shell grit (crushed oyster shell) with each 22 litre fermenter pail. Our domestic water supply is also very soft. There is very little shell material remaining in the pail after a ferment

  • Typically I’m moving between 4 and 5. Start I’ll go from 4.5 to 5.5 or somewhere thereabouts.

    After the start I’m typically trying to keep it around 4.5-5 and moving up to this about 1/2 point.

  • Well tried it this morning. I dropped from 5.5 to 4.0 overnight. I tried a few doses and settled on 75g of sodium hydroxide. This brought ph to 5.1

    This is roughly half what I would have needed with sodium bicarbonate and very little foaming was seen.

  • edited May 2019

    I really like the crushed coral idea for a local Fijian spirit. Makes for a very unique marketing proposition, it's very local, and very memorable. The only challenge is making people realize that it's not fermented with seafood... :))

    You can get fancy and say it's fermented with aragonite crystals, formed in the growing coral skeleton.

    Aragonite crystals are very important to reef biochemistry, in seawater it helps stabilize pH, and remove carbon dioxide.

    Exactly the same conditions you might find in a fermenting wash. Aragonite will also typically contain essential micronutrients like Zinc and Magnesium, also beneficial to yeast health.

    You can tell a really compelling story.

  • You SOOO fucking get it...

    (25kg Flour sack*2+bad attitude)+taxi+beach+coral+long walk=Today

  • Forgot the six pack of ale and the big hat.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • I used to use Calcium Carbonate to raise pH but it doesn't dissolve very easily and the effect on the pH is relatively small (i.e. you have to use a fair bit to get a meaningful shift). I now use Potassium Carbonate. It's fantastic. Easy to dissolve, easy to obtain in the UK and don't need anywhere near the same quantity. Unless you want to handle seriously caustic chemicals, this is great for hobby use

  • I skipped through sea shells, to chicken calcium to decorative marble rock!

    I put two pounds of marble rocks in a vented 2 litter soda bottle and hang it in a 170 gallon ferment. The ferment will eat half the rock but only as needed and stay 4.5-5.0 for a week or more if needed.

    Big adjustments and post distillation I raise the Ph for feeding to the digesters to 6.5 with calcium hydroxide Ca(OH)2 and agitation. The same stuff the water plants use for drinking water. 40lbs runs about $10usd. It is usually ground very fine and dissolves better than calcium carbonate.

    Ca(OH)2 does require a little more safe handling.

    DAD... not yours.. ah, hell... I don't know...

  • @dad said "digesters" lol. :))

    StillDragon North America - Your StillDragon® Distributor for North America

  • I was only able to get some coral blocks. We chipped them up into smaller pieces and will try shortly.

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