Expired Lime

[Triggerfish]

any issue if not used by the "sell by date:" ?

 

[reverendmaynard]

As long as it's dry and not clumpy, should be ok.

 

[Triggerfish]

yeah,,it looked good. real fine and powdery. thx
i was using it anyway

 

[Greg Hiller]

The only thing that could happen to it anyhow is that it could absorb water and become Ca(OH)2 if it was CaO to begin with, or absorb CO2 and become less potent. Also not a problem.

 

[marco67]

And the less scientific answer....it's lime, it's already a million years old...when exactly does it expire again?

 

[Greg Hiller]

Marc,

It's true, but CaO, or Ca(OH)2 are not naturally occuring to my knowledge. The calcium carbonate (the mined stuff) I think needs to 'cooked' to....ah...here's a reference on how it's made:

http://www.encyclopedia.com/html/c/calciumo.asp

"It is prepared by heating calcium carbonate (e.g., limestone ) in a special lime kiln to about 500°C to 600°C, decomposing it into the oxide and carbon dioxide. "

 

[marco67]

Hmmm interesting to know ...thanks
Still though don't you think the expiration date is more a function of the Mrs Wags being sold as a food product (FDA getting involved) than the CaO2 actually going bad?

 

[reverendmaynard]

AFAIK, the only thing that can "go bad" with this stuff is if it recombines with co2 to make calcium carbonate again. For exact recipes, or uses where any precipitate would ruin the batch, that could be a bad thing. For our purposes, we usually add more than enough to saturate anyway, so a little lost potency, and/or precipitate in the bucket isn't likely to mean much.

 

[Greg Hiller]

Marc,

Yes, I didn't know it was the food type material, couldn't tell from the question. Even if it was not, I don't think expiration date on this product has much meaning at all. Quite frankly, that's true for a great many chemicals if you understand what they are, and their potential for breakdown or not.