Start from output, not the drum
The question is not how big a drum you can afford. It is how much roasted product you need per session, and how many sessions you are willing to run.
Nuts have one sizing quirk that coffee does not, and it catches people out.
In-shell is bulk without weight
A pound of peanuts in the shell takes up dramatically more space than a pound shelled — the shell is mostly air. So a drum sized on weight will be badly undersized if you are roasting in-shell.
If in-shell is your main product, size up at least one step from whatever the weight suggests. If you switch between in-shell and shelled, you want a drum with a wide working range rather than a fixed capacity.
The sizes
| Drum | Suits |
|---|---|
| 2 LB | Learning, gifts, one nut at a time. Small enough that a batch you get wrong costs almost nothing — which matters with nuts, where the window is narrow. |
| 4 LB | The common front door. Holiday runs, farmers markets, steady gifting. |
| 6 LB | A regular market stall or side business. Where in-shell peanuts start to make sense at volume. |
| 8 LB | Steady commercial output. Pair with a real cooler — at this size, cooling governs cycle time. |
| 12 LB | Volume production. 10″×24″ drum on a commercial 26 RPM motor. |