The first three months of aging your beer in the bottle makes a big difference to its character and its head retention. Unlike some commercial beers that have a short shelf life, the more malt and the more hops in the beer, the longer it can age. The British increased the hops in their beers to make the journey to India, e.g., India Pale Ales.
Our Barons kits have more malt and hops than most other kits so have that ability to improve over the first year. Lighter beers, like our Belgian Wit and Kolsch, should be consumed in the first year, but our heavier beers such as our Pale Ale and Stout can be fine for a couple of years if stored in a cool, dark, stable place after carbonation.
Beer stored in glass beer bottles will improve over these time frames, but beer in plastic bottles (plastic being permeable ) , we will see a leveling off of improvement after the first three months. So, drink those ones young. Above all, proper storage is the key to getting the most from your beer cellar.