This is a great question, and one that touches on the beautiful interplay between wine and wood. The short version is that the smaller the barrel, the more oak contact your wine will have. Because the ratio of wood surface area-to-wine volume increases as the barrel size goes down, the wine in a 5- or 10-gallon (19- to 38-L) cask will pick up oak flavors (and tannins) much more quickly than the same wine in a standard 59-gallon (225-L) barrique.
That can be a positive thing — if you’re after oak toast, vanillin, or spice characters, a small barrel can deliver them in a fraction of the time. But it can also be risky. With so much wood per gallon/L, a delicate red can easily tip from “nicely structured” into “over-oaked” before you know it. Commercial wineries keep a close eye on their barrel-aged lots for exactly this reason, and with a small barrel it’s even more important to taste regularly (think every week) rather than waiting months between samplings.
There’s another difference to be aware of, and that’s oxygen. Wine doesn’t just extract flavor from oak; it also breathes through the barrel staves. That gentle oxygen exchange helps soften tannins and develop complexity over time. In small barrels, oxygen ingress per gallon/L is again higher. This can be beneficial for a young, robust red that needs some taming, but it also means your wine could advance through aging stages faster than you expect. If the wine is light in body or already quite mature, it may tire quickly in a small cask if left for too long.
Some winemakers use a hybrid approach — aging part of the batch in a small barrel for oak and structure and keeping the rest in glass or stainless. Later they can blend to taste, adjusting the oak profile to suit the wine rather than letting the barrel call all the shots. The portion in stainless or glass, especially when kept as “breakdown containers,” i.e., as full as possible, serve as useful topping wine for the small barrel. You’re going to need it with the more frequent tasting regimen you’ll be implementing! Even with small barrels you need to top up regularly to minimize oxygen inside.
So yes, those little barrels can be wonderful tools, but treat them with respect. Their influence is stronger, faster, and less forgiving. With a careful hand (and frequent tasting and re-topping), you can absolutely make beautiful red wine in them — just don’t expect them to behave exactly like their bigger counterparts.
