Regarding the quantity, would a mason jar be overkill in a 5 gallon batch?I had an offer to have a "mason jar of yeast" given to me by a local brewery. Sounds fun, but not sure how I'd store it, use it, etc. Any thoughts are welcomed!
When I do that, it's for immediate use.
Depends on the size of the mason jar.
Put it in the fridge until you are ready to use it, and you will probably need just a little bit. Maybe 100ml.
Think about how much yeast is in a smack pack or vial.
The yeast you are getting will be a thicker slurry and should be healthy and active.