The right still size depends on how much accepted spirit you need and how often you can produce it. Start with your sales target, bottle size and bottling strength. Then work backwards through the actual production route. Boiler volume alone cannot tell you how many bottles your distillery will sell or produce.
Start with bottles, then calculate the alcohol
Suppose your target is 10,000 bottles a year, each containing 700 ml at 40% ABV. That is 7,000 liters of bottled product containing 2,800 liters of pure alcohol. These are planning assumptions, not an equipment yield claim.
If you allocate 100 distillation days to that product, you need an average of 28 liters of accepted pure alcohol per day. At 50 days, the daily requirement doubles to 56 liters. Allow separately for rejected fractions, transfers, sampling, proofing and bottling losses. For aged products, include the maturation period and losses in the cask plan.
| Planning input or result | Example |
|---|---|
| Bottle volume and strength | 700 ml at 40% ABV |
| Finished product | 7,000 liters per year |
| Alcohol in finished product | 2,800 liters of pure alcohol per year |
| With 100 distillation days | 28 liters of accepted pure alcohol per day |
| With 50 distillation days | 56 liters of accepted pure alcohol per day |
This calculation gives you an output requirement. To turn it into a boiler size, you still need the charge strength, permitted working fill, accepted recovery and number of cycles you can actually complete.
Purchased-base gin and grain-to-glass need different capacity
A gin distillery buying neutral spirit starts with alcohol already made. It needs a workflow for base storage, botanical preparation, extraction or redistillation, dilution and bottling. A whisky distillery making its own alcohol also needs grain handling, mashing and fermentation before the still receives a charge.
For illustration, 100 liters at 10% ABV contains 10 liters of pure alcohol; 100 liters at 30% contains 30 liters. That is an alcohol balance, not a recommendation to charge either mixture into a particular still. Use the operating limits for the actual equipment.
The different starting strengths explain why the same nominal boiler can serve very different bottle targets. The number of distillation passes and your chosen cuts also change accepted output. A gin output example should never be carried straight across to grain-to-glass whisky.
Find the vessel that sets the working week
Map a complete week, including filling, heating, the run, emptying, cleaning and changeovers. If you mash, ferment and distill in one vessel, those jobs occupy the same vessel at different times. Flexibility can reduce the number of machines you buy, while dedicated fermentation capacity can let a still work more frequently.
- How many production days can the team staff?
- How many fermentations must be ready for those days?
- Do several products compete for the same still?
- Where do proofing, holding and bottling constrain finished output?
- What spare capacity covers maintenance and a rejected batch?
Compare models against the plan
Use the yearly production capacity calculator to explore your assumptions, then compare the current production models. Check working capacity, configuration and utilities for the chosen process. Keep initial demand and a realistic expansion scenario separate so that an optimistic forecast does not become an oversized purchase.
For the rest of the decision, continue with pot, plated and hybrid still designs and the new-distillery production plan.
