Wood is a porous material so your Urban Barrel will absorb flavours from every batch (this is known as “the Devil’s cut”). For example, when you age whisky in an oak barrel, some of its flavour will carry over to your next batch.
Whether it’s a good thing or a bad thing, that’s up to you and your taste buds to decide.
You might prefer using separate oak barrels for each type of spirit. But we think one of the joys of barrel-aging at home is the ability to experiment with different flavour combinations to end up with something that’s all your own. Just keep in mind that no two batches are the same.