Myth check
A sealed growler or crowler stays fresh for months like retail cans.
Mostly false
Bottom line
Takeaway fills are best enjoyed sooner; oxygen and time degrade many beers.
Explanation
Commercially packaged retail beer and a filled growler/crowler are not always equivalent in intended shelf life.
Hop aroma especially fades. Keep vessels cold and follow brewery guidance; when in doubt, drink sooner.
Policies and seal quality vary — ask at fill time.
Better framing
Plan growlers and crowlers for near-term enjoyment, not long cellaring, unless a brewery gives specific guidance.
Educational myth check for adults 21+. Confirm brewery facts on official sources when visiting.