Small barrel aging — am I wasting my time with a 2-liter barrel?

You're not wasting your time, but you ARE fighting physics. Small barrels over-extract tannins fast, which is exactly what you're tasting. Here's the thing — the mellowing and esterification that gives bourbon its complexity happens on a timeline that doesn't compress as well as the color extraction. My suggestion: pull it at 4-6 weeks MAX, then let it rest in glass for another month. The flavors will integrate and mellow significantly in the bottle. Then do a second run in that same barrel — the wood will be less aggressive and you'll get better results. Also, charred 2-liter barrels are great for finishing. Age your base spirit in the biggest barrel you can get, then finish in the small one for 1-2 weeks.

I experimented with a 1-liter barrel last year for cocktail aging (not quite distilling, but same wood science). Brian's right about the over-extraction. What helped me was doing a "sacrificial run" first — filling the barrel with cheap bourbon or even water with a splash of vinegar for a week to pull out the harshest tannins. Then your actual spirit goes in and it's much more balanced. Also, temperature swings help. If you can put the barrel somewhere with day/night temperature variation (garage, shed), the expansion/contraction drives the spirit in and out of the wood more naturally.

This is incredibly helpful. I'm going to pull it this weekend and let it rest in glass for a few weeks. The sacrificial run tip is genius — wish I'd known that before. I'll definitely do that before the next batch goes in. Follow-up question: has anyone tried using different wood types in small barrels? I've seen cherry and maple options online. Worth experimenting or just stick with oak?