Match the load you actually generate, then check the circuit it needs. A five-tray medium chassis at 15 lb per load covers most households and runs on an ordinary 15A wall outlet. A large chassis at 25 lb wants a 20A circuit. Commercial machines need 240V wired in.
Sizing by household and use
| Your situation | Chassis | Why |
|---|---|---|
| One or two people, occasional batches | Medium, 5 trays | 15 lb per load is more than it sounds; a full set takes a day to prep |
| Family of four, regular preserving | Medium or Large | Medium if you run it weekly; Large if you process a harvest in bursts |
| Garden or allotment glut | Large, 25 lb | Gluts arrive all at once. Capacity beats speed here |
| Prepping a one-year supply | Large | You are running consecutive batches for months; bigger loads mean fewer cycles |
| Selling at markets | 7-shelf or two machines | Redundancy matters more than size once you have customers |
| Wholesale or production | XL Commercial, 240V | Duty cycle, not capacity, is what you are buying |
The mistake in both directions
Buying too small is the more common regret, and it shows up as running two cycles where one would have done — which doubles both your electricity and your elapsed time. Buying too large is less common but wastes money differently: a half-full machine uses nearly the same energy as a full one, because the compressor is cooling the same chamber regardless.
Tray area is the number to compare, not tray count
Five trays means nothing on its own. The Blue Alpine Medium’s five 9×13 in trays give 585 sq in; the Stay Fresh Premier Pump’s five 8×20 in trays give 800 sq in. Same count, 37% more surface. Multiply length by width by tray count and compare that figure.
But cold trap capacity is the real ceiling
Here is the thing manufacturers rarely lead with: what limits a batch is not how much food fits on the trays, it is how much water the cold trap can hold as ice before it saturates. Stay Fresh publishes 12 lb of ice capacity on its five-shelf model. If you load 18 lb of watermelon, most of that weight is water, and the trap will be the constraint rather than the trays.
This is why the same machine handles 18 lb of dense vegetables and struggles with 12 lb of high-moisture fruit. Load by water content, not by weight.
Check your breaker before you order
| Chassis | Circuit needed |
|---|---|
| Blue Alpine Medium | 120V, 15A |
| Blue Alpine Large | 120V, 20A |
| Blue Alpine XL Commercial | 240V, 30A (L6-30) |
| Stay Fresh 5-shelf | Dedicated 15/20A recommended |
| Stay Fresh EU models | 220–240V 50Hz |
See the seven machines with their circuits
Every machine we cover, with its electrical requirement stated.
