What is the benefit of using different barrel sizes?
The volume of the wood container is an excellent way to control both the wood's aromatic contribution and the oxygen contribution. The larger the container, the smaller the oxygen contribution per litre of wine. For more fragile wines, maturing in larger barrels can be beneficial. Similarly, from an aromatic point of view, the larger the volume, the less the wine is impacted by the wood aromas. Large barrels are particularly suitable for white wines, and red grape varieties that are more sensitive to oxygen or easily impacted by wood such as Gamay.
From a logistical point of view, having a few containers of various sizes enables greater precision in the separation of the batches and the wood/wine balance.