Can diatomaceous earth (DE) go bad/become contaminated?

[DaveB]

While the sap has been flowing decently I'm still waiting for enough to fire up my new evaporator. After I got everything setup I started doing some "spring cleaning" around the sugar house and I found an open bag of DE under one of my benches and I'm wondering if it can go bad. I know it's ground up skeletons of ancient plankton but can it become contaminated? I think it's from three seasons ago and I had totally forgotten about it.

Thanks!

[Michael Greer]

It's probably pretty inert....it's already millions of years old...so I'd only worry about regular old dust and dirt and mouse poop. Throw away the top few inches.

[PARKER MAPLE]

I was wondering the same thing. my bag got opened and well we taped it shut but the top reopened I guess when we moved it around.
Is there any harm in using this stuff again this year??

[DrTimPerkins]

DE itself won't spoil, but if not sealed up well, and your sugarhouse is humid, then it can get musty. If you filter with it, your syrup will taste musty.

[Paul VT]

I don't have a press so I don't use any. But a friend last year had some in what was a sealed plastic container that was full of mold. It was left over from the year before. I personally would throw out parcel bags at the end of the season and get fresh the next. Not worth making good syrup bad when filtering.
Just my thoughts.

[johnallin]

After all of your hard work and only about $1 per pound in small quantities - why risk it? That's like running a 26 mile marathon and not crosising the finish line.

[happy thoughts]

I wouldn't risk it either. There's too much time and effort getting it to syrup to waste it at the end. You can always re-purpose the old DE in your garden to take out slugs.