Jeff,
Haven't used this type but have used other boilies from the dynamite baits stable. Shelf life boilies will be OK for up to 6 months once the packet is opened. Store in a dry, cool and dark place with the bag re-sealed to prevent cross contamination of flavours from other baits. I use a small table top bait fridge.
Freezer baits will keep more or lessindefinitely provided you don't let them thaw. However, I still like to use them within 12 months as I would anything else from a -18 degree C domestic freezer.
It's been said before, but it's worthy repeating. Bait manufacturer's note:
We pay good money for your products. INCLUDE A "BEST BY" DATE!!!!! NOW!!!! Because we're worth it and you want us to buy your products.