Lambic is one of the few beers capable of being aged for many years. This is because the beer contains microorganisms that continue to develop at different rates and change the characteristics of the beer. Additionally, oxygen can work with these yeasts (such as Brettanomyces) to change the characteristics of the beers over time. Lambic is commonly sought after if it has been bottled between 0 and 15 years, though bottles dating back through the past 100+ years are still occasionally opened and reported to be drinkable. [[Brasserie Cantillon|Cantillon]] recently started their [[Brasserie Cantillon#Underground Cellar|Underground Cellar]] project where they are working to age lambic in controlled conditions with minimal interaction.
Lambic, like wine, is most commonly stored on its side. This orientation expands the surface area of the beer that is in contact with the oxygen in the bottle. It also places the beer in contact with the cork. While the cork will remain moist even if the bottle is upright because of the 100% humidity in the bottle, storing the bottle sideways may still have an effect on the lead to more ullage of a beer by keeping the cork in contact with liquid rather than air. HoweverAlso, if the cork breaks down with age, direct contact between the beer and cork can lead to Trichloroanisole (TCA) "corked" flavors in the beer. Brewers continue to experiment with corks and continue to invest in higher quality corks that should allow for better aging of lambic in the future.
Lambic also contains natural yeasts and microorganisms which can lead to considerable sediment in the bottle while it ages. Fruits can further contribute to the sediment in a bottle. By storing the beer on it's side, the yeasts will settle along the side of the bottle. When a basket is used for serving, the bottle is kept on its side, allowing the yeast to stay in this state and reducing what sediment gets poured into the glass.