Crushed Oyster shell

[8Ball]

I bought a 5 gallon bucket of clean, crushed shells for around $10 at the feed store a couple years ago. Filled up a quart container with them and added StarSan mix for about an hour. Drained it all off, rinsed, and let it completely dry in the sun. Put it back in the container and now I have good sanitized grit. Use a couple handfuls in a cheese cloth sack for a 8G total ferment. So far so good.

[stevexxx]

An alternative is egg shells..

[wpkluck]

An alternative is egg shells..

Steve, can you tell us how they work, and how to use them (including how many needed for a 5 gal mash), and other factors? Thanks!

[stevexxx]

An alternative is egg shells..

Steve, can you tell us how they work, and how to use them (including how many needed for a 5 gal mash), and other factors? Thanks!

I'm not very scientific with it I'm afraid, Any shells from eggs I wash out and place in a a bowel in the oven baking them when we next do a meal. crush them up a little and toss in about 3 handfuls in a 25litre wash then another after a couple of days. I do need to adjust the Ph after 24 hours but after that it seems to hold pretty well to the end.. So basically just use in the same way as oyster shells both being calcium carbonate..

[wpkluck]

Stevexxx said:
I'm not very scientific with it I'm afraid, Any shells from eggs I wash out and place in a a bowel in the oven baking them when we next do a meal. crush them up a little and toss in about 3 handfuls in a 25litre wash then another after a couple of days. I do need to adjust the Ph after 24 hours but after that it seems to hold pretty well to the end.. So basically just use in the same way as oyster shells both being calcium carbonate..

Steve, this is helpful! I was wondering how you prepared it, how much, and how added. You gave all that. Thanks!

[greggn]

An alternative is egg shells..

Another alternative is marble chips ... readily available in the landscaping section at the big-box home improvement stores.

[rubberduck71]

Hop socks are very cheap at your local HBS (or online). Just put a cup of crushed shells (avail at most feed/grain stores) in a sock & toss it in your typical 6 gal/25L fermenter. Should keep things in the 4.0-5.0 pH range.

[Windswept]

An alternative is egg shells..

Another alternative is marble chips ... readily available in the landscaping section at the big-box home improvement stores.

Marble would work, but what is usually sold as landscaping marble has been dolomitized to some extent, and because dolomite is CaMg(CO3)2 it's noticeably less reactive to acid (that's how you tell the difference between calcite and dolomite).

Bottom line, would work, just not as well and it would add magnesium which might have other consequences.

[nerdybrewer]

shell.jpgI used 2 fairly large shells.That are about two-thirds the size of my hand. I drill a hole in them and hang them from a copper wire into the wash. I just wash off the crud that builds up on them and use them in the next wash. Works perfect . One time I guess the acidity got pretty high It looked like somebody took a shotgun to My shells they were full of holes.
It's a great pH buffer

I buy the oysters fresh Obviously eat the inside. then I washed them off, toss them in the oven at about 350 degrees for about half an hour To make sure all the Unwanted critters are dead

This is the way.

I bake them at 400F for half an hour, 350F is good but heck more is usually better right?

I started with crushed then went to this method because A) I really enjoy oysters and B) it's way less trouble
Just wash off the shell between ferments.
My experience is that the fermenting wash only uses what it needs.

[Rrmuf]

An alternative is egg shells..

Steve, can you tell us how they work, and how to use them (including how many needed for a 5 gal mash), and other factors? Thanks!

I'm not very scientific with it I'm afraid, Any shells from eggs I wash out and place in a a bowel in the oven baking them when we next do a meal. crush them up a little and toss in about 3 handfuls in a 25litre wash then another after a couple of days. I do need to adjust the Ph after 24 hours but after that it seems to hold pretty well to the end.. So basically just use in the same way as oyster shells both being calcium carbonate..

That's a good suggestion: We go through alot of eggs in our household!

[heynonny]

I save (when I need them) egg shells, put 'em on the window sill above the sink.When I run outta room, I have a coffee grinder I bought at a yard sale = $1.00 & grind the shells to a fine powder, till I have a quart or so. I add a cup + to 15 gallons, , , ,

[Demy]

really like this discussion. Until now I have only used baking soda to monitor the pH of sugar washes. I ask the very experienced guys, is there any benefit to changing my method (other than the "self-correction" of oysters & co)?

[Durhommer]

I've used oyster shell since the beginning of my career

[SomethingObscure]

So the people that say the ferment only uses what it needs are wrong?

They haven't done their homework.

So I'm a little confused by this subject. I've read quite a few post now that mention. That oyster shell can be used as a preventive measure against pH crash. And that pickling lime should be used to recover a pH crash.

I'm way to inexperienced to add more to this discussion. So I thought I'd experiment.

I'm going to take 5 liters from my latest ferment which I started yesterday. And I'll add a handful of crushed oyster shell grit (for chickens) in a sock. Then measure the pH daily.

Cheers SomethingObscure

[shadylane]

A handful of shell grit in 5L.
That's how much I'd probably use in 20L.
Go for it

[kimbodious]

I use 1/3 cup of shell grit in a 24 L wash. There is very little left at the end of the ferment.

[SomethingObscure]

What I want to test is if you leave the shells in whether the pH will continue to rise to undesirable levels

Cheers SomethingObscure

[wpkluck]

What I want to test is if you leave the shells in whether the pH will continue to rise to undesirable levels

Cheers SomethingObscure

People here seem to say no, the ferment will only use what’s needed. I was chastised by someone for asking if the shells got used up, they told me why would I they dissolve when they don’t dissolve in the ocean. I did some research, and it appears they dissolve in acidic waters, but slow down dissolution near 7pH (neutral). Makes sense, but I have no experience with it (yet).

This would tell me you could hang a sock with shells, and use them prophylacticly. I’ve never heard anyone complain it pushed pH too high.

[SomethingObscure]

... but slow down dissolution near 0pH. Makes sense, but I have no experience with it (yet).

I'm guessing you mean 7pH (meaning neutral). Or do you mean higher than that?

This would tell me you could hang a sock with shells, and use them prophylacticly. I’ve never heard anyone complain it pushed pH too high.

That's what I'll test over weeks or months or until I runout of storage and need the demijohn [emoji4]

This thread has confused me on a subject I thought I'd already studied and drawn conclusions on.

Cheers SomethingObscure

[wpkluck]

I'm guessing you mean 7pH (meaning neutral). Or do you mean higher than that?

Yes, you’re right. I went back and corrected.

[wpkluck]

This thread has confused me on a subject I thought I'd already studied and drawn conclusions on.

There’s no way we can know everything about everything! Every great diamond has lots of facets. And I would say that none of them has only one.

Here’s another twist: I’m wondering if it’s just oyster shell, or are there other kinds of shells that would work. I have lots of shells that the kids have picked up over the years, in boxes, dioramas, etc.… I’m wondering if any of those shells could also be crushed up and used. Looks like more time to research!

[subbrew]

Any sea shell is mostly calcium carbonate (CaC03). Fermentation creates acetic acid (CH3OOH) when shells are added to they react with the acid forming a salt, carbon dioxide and water (CaCO3 + 2CH3COOH → Ca(CH3COO)2 + H2O + CO2). As the acid is neutralized by the shell the reaction will slow. It would take a long time for shells to cause a liquid to turn alkaline (ph > 7). It would eventually happen but we are talking months. that is why shells make a great buffer. As the acid content increases the reaction with the CaCO3 increases to neutralize the acid and vise versa, with little acid the reaction slows.

The relatively small surface area of shells compared to a powder such as chalk means they work more slowly.

[wpkluck]

Any sea shell is mostly calcium carbonate (CaC03). Fermentation creates acetic acid (CH3OOH) when shells are added to they react with the acid forming a salt, carbon dioxide and water (CaCO3 + 2CH3COOH → Ca(CH3COO)2 + H2O + CO2). As the acid is neutralized by the shell the reaction will slow. It would take a long time for shells to cause a liquid to turn alkaline (ph > 7). It would eventually happen but we are talking months. that is why shells make a great buffer. As the acid content increases the reaction with the CaCO3 increases to neutralize the acid and vise versa, with little acid the reaction slows.

The relatively small surface area of shells compared to a powder such as chalk means they work more slowly.

Great info! Thanks!

[WIski]

A handful of shell grit in 5L.
That's how much I'd probably use in 20L.
Go for it

Shady is right. I use crushed shells on every all grain ferment with or without backset. One hand full in a 32 gallon batch and when I squeeze the grains there are still bits of shells visible. PH always stays in the sweet zone. I am a firm believer in crushed shells sold as chicken grit at farm stores. YMMV