A Barrel-Aged Mead is similar to the Wood-Aged Mead category, except that meads are aged in barrels that previously held other contents (beer, wine, cider, spirits, other food products) and now feature both the wood and the previous contents as added character.
Overall Impression
Any style of mead that features a used barrel character at a noticeable level, but still in a way that is balanced, pleasant, and enjoyable. The barrel character should not completely dominate the mead, but can play up to an equal role as the other ingredients. Both the barrel and the prior contents of the barrel should play a role in the final product.
Appearance
Same as the base style of mead, possibly with darker shades of color or colors that reflect the prior barrel contents.
Aroma
Same as the base style of mead, possibly with balanced, pleasant aromatics associated with the declared barrel, prior barrel contents, and any process details. The barrel-derived aromatics should complement and enhance the base mead, not dominate it.
Flavor
Same as the base style of mead, with added flavor from the declared barrel, prior barrel contents, and any process details. The barrel-derived flavors should complement and enhance the base mead, not dominate it. The best examples exhibit a coherent, intentional synthesis of flavors.
Mouthfeel
Same as the base style of mead, possibly with added tannins from the wood giving a drying quality and additional body. Barrels may increase the alcohol warming impression and alter other mouthfeel components, depending on the nature of the prior barrel contents.
Characteristic Ingredients
Any mead style. A barrel or wood product that previous was used to age or mature beer, wine, cider, spirits (whiskey, gin, rum, cachaça, etc.), or food products (maple syrup, hot sauce, etc.).
Entry Instructions
Entrants must specify sweetness, carbonation, and strength levels. Entrants must specify a base style, as well as any components typically required by the base style. Entrants must specify the type of barrel used, prior barrel contents, and may specify additional process details.

Comments
Meads featuring only a base character of wood (even if barrel-derived) should be entered in M4D Wood-Aged Mead. Those meads featuring a mix of M4D Wood-Aged Mead and M4E Barrel-Aged Mead should be entered in this style.