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Howdy y'all,

I'm re-reading Arroyo's circular 106 on Rum manufacturing by Boston apothecary

For those that haven't read it...
https://www.bostonapothecary.com/circul ... royo-1938/

Specifically on the pretreatment of raw materials.
He recommends making a molasses and water slurry, then treating it with lime/acid to a starting pH of 5.8, then add lime to 7, then acid back down to 5.8.

He says this is "establishing the buffer" what do you suppose he means by that? Doesn't the acid cancel out the base? Wouldn't the use of something like oyster shell be more of a buffer than adding lime slurry then nullifying it?

Thanks
B

https://en.m.wikipedia.org/wiki/Buffer_solution

A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.

Cheers,
J

jonnys_spirit wrote: ↑Mon Apr 24, 2023 5:54 pm https://en.m.wikipedia.org/wiki/Buffer_solution

A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.

Cheers,
J

Well shit, that makes perfect sense, thanks!

Bolverk wrote: ↑Mon Apr 24, 2023 6:02 pm

jonnys_spirit wrote: ↑Mon Apr 24, 2023 5:54 pm https://en.m.wikipedia.org/wiki/Buffer_solution

A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.

Cheers,
J

Well shit, that makes perfect sense, thanks!

When yeast ferment they produce acids which will drop the pH and therefore stress the yeasties - which we usually want to prevent.

Don’t Stress The Yeast!

Cheers,
J

jonnys_spirit literally beat me to the post - of the same Wikipedia link, by only a minute or by seconds.

Limestone is made by deposits from calcareous skeletons from sea-life (and like oyster shells left behind), and lime is made from limestone. Oyster shells and lime are the same thing - calcium hydroxide. The pH interchange works quicker and better using powdered or slurried lime.

jonnys_spirit wrote: ↑Mon Apr 24, 2023 6:08 pm [
When yeast ferment they produce acids which will drop the pH and therefore stress the yeasties - which we usually want to prevent.

Don’t Stress The Yeast!

Cheers,
J

I had always started the yeast with a high enough pH so that the crash didn't go too low, but this is pretty brilliant

contrahead wrote: ↑Mon Apr 24, 2023 6:09 pm jonnys_spirit literally beat me to the post - of the same Wikipedia link, by only a minute or by seconds.

Limestone is made by deposits from calcareous skeletons from sea-life (and like oyster shells left behind), and lime is made from limestone. Oyster shells and lime are the same thing - calcium hydroxide. The pH interchange works quicker and better using powdered or slurried lime.

Thanks for this

I'll be picking some up soon

My take on buffering is that a normal ph up like calcium carbonate is a low solubility in water. Much higher in acid. By adding both acid and CC you dissolve more calcium, this makes the ph drop slower. Not a chemist, so I don’t know the exact reaction, but I can say it works.

Similar to an acidic solution dissolving coral and raising ph. But by building the buffer, the calcium is already in the solution.

Bolverk wrote: ↑Mon Apr 24, 2023 5:08 pm
He says this is "establishing the buffer" what do you suppose he means by that? Doesn't the acid cancel out the base?

Yes, they cancel each other.
After that it's "buffered" and the pH doesn't change as easily.

contrahead wrote: ↑Mon Apr 24, 2023 6:09 pm

Limestone is made by deposits from calcareous skeletons from sea-life (and like oyster shells left behind), and lime is made from limestone. Oyster shells and lime are the same thing - calcium hydroxide.

I think Ya meant calcium carbonate.

There are at least two mistakes in this thread. Both should be easily found if you do your homework.

Also, make sure you read the whole of Arroyo's circular and find the warning in it.

shadylane wrote: ↑Mon Apr 24, 2023 10:08 pm
I think Ya meant calcium carbonate.

Yup. CaCO3. My whole speach was a little confused. Either typing too fast or brain muddled by homemade liquor...

contrahead wrote: ↑Mon Apr 24, 2023 10:31 pm
Either typing too fast or brain muddled by homemade liquor...

Your forgiven this time.
I get to take another shot and make the next mistake.

Another explanation.
https://www.westlab.com/blog/what-is-a- ... es-it-work

Calcium hydroxide is another term for slack lime, something I learned here. I have used it in hydro.

Tōtōchtin wrote: ↑Tue Apr 25, 2023 10:34 am Another explanation.
https://www.westlab.com/blog/what-is-a- ... es-it-work

Calcium hydroxide is another term for slack lime, something I learned here. I have used it in hydro.

It's slaked lime, not slack lime.

When it has come to using all molasses to make Rum , I have never found any reason to add buffers .
The Buffer is already in the Molasses as part of the sugar refining process .
During refining they add Calcium Hydroxide as part of the Clarifying process . Then Phosphoric acid is added to lower the pH again . This is done at least twice .

Ever tried to adjust the pH of an all Molasses wash ??? Try it .
Forget a teaspoon of citric acid or a few sea shells . We are talking about several 100mls of concentrated Hydrochloric acid or 1/2 a cup of or more of Calcium Hydroxide . The stuff is so ph solid that all the CO2 created during fermentation barely moves it by 0.5pH .

Its nothing at all like a sugar wash .

I didnt know that, and it explains a lot.

Thanks!

You were correct in my mis-spelled word. Another product I used in hydro was potassium silicate. I used that in my nutrient solution to fight runaway drop in pH due to an infection. Works great as a preventive pesticide also.
Tōtō