Put it in a mason jar. Add C02. The C02 is heavier than oxygen and will displace the O2 in the jar which will keep the cronic from oxidizing. Seal the jar and keep it in a cool dark place. A good source of C02 for this purpose is C02 wine savers which can be found in any store that sells decent wine.

If you will be storing often, paint a few mason jars black and have them at the ready.