Found a bunch of specialty grains I'd intented for a beer but lost to time. They've been in brown paper bags for well over a year.
Is it worth using them at all for a small batch or has time/air ruined extraction, ruined flavor, etc?
I buy my 2-row in 40kg bags which lasts me one or two years, no problem there. The flavor is not an issue, the gravity will still be there.
However, when it comes to speciality grain, if they are not crushed it is much better.
After crushing them, they will lose their freshness quickly if not sealed properly, and flavor fades a little. The roasted flavor of black malt, chocolate or crystal malts isn't something that fades too much, but the smoked malt will definitely be less smoky after a year.
I would probably use it, but mixed with fresh grain otherwise the beer might be too bland.
I ordered too large of a bag of roasted chocolate grains, so I've had it two years now. I store it in a dry place, checking regularly to make sure the grains look and taste fine. I've used them in multiple beers over 2 years and had no issues.
Granted those are really flavorful grains, so that may help. But I didn't taste any difference between the first beer done two years ago, and the last one 6 months ago with the same recipe.
I would say you are fine.
I have used grains that old and it's been fine. Maybe if you have some kind of super palate you might be able to tell the difference but my friends and I can't.
The only time I would be cautious of using old grains are if they have gotten damp but even then I would probably give it a go!
If they have mould or look visibly infected with something I would chuck them away.