Barrel Aged beers cannot generally be described as top-fermented or bottom-fermented, as theoretically a variety of different beer styles can be stored in kegs.
In the past, beer was always stored in wooden barrels - until the time when metal barrels largely replaced them. The difference to today's method of "Barell Aging" is that what is important is what was previously stored in the wooden barrel. Whether whiskey, rum, wine or other spirits. The willingness to experiment has no limits. The aromas of the drink, which was first stored in the wooden barrel, penetrate the wood. The beer, which is then filled into the empty but already used barrel, absorbs the aromas of the previous drink and refines the beer. This is how completely new beers are developed and created. Stouts , Doppelbock beers and barley wines are particularly good for the “barrel aging” process.