Adding a pilot system to a brewpub for recipe development

What a pilot system is for

A pilot system is a small brewhouse, often 20 to 100 litres, used to test recipes before brewing them at full scale. The aim is to answer questions cheaply. Does this new hop combination work? Is the dark malt too harsh at this rate? Do guests like a rice lager better than a maize one?

A failed 50 litre batch costs a few kilos of malt, a few hundred grams of hops and an afternoon. A failed 1,000 litre batch costs twenty times the ingredients, a fermenter tied up for weeks and a tap with nothing good to pour. For a brewpub that rotates seasonal beers, that difference adds up fast.

When it pays and when it does not

A pilot system earns its place when you launch new beers often, run collaborations or want to test styles before committing tank space. It is less useful if your tap list barely changes, or if your main brewhouse is already small. On a 300 litre system, a test batch at full scale is not a huge risk.

Count the costs honestly. Equipment, space, a few small fermenters, brewer time and ingredients all add up. A pilot brew takes nearly as long as a full one. If your head brewer is already brewing four times a week, a pilot system with no extra staff time may never be used.

Choose a size that teaches you something

Too small and the results do not transfer. A 10 litre batch behaves differently from 1,000 litres in hop utilisation, boil-off, cooling time and fermentation temperature. Too large and you lose the cost advantage. Many brewpubs settle on 50 to 100 litres, enough to fill a keg or two for a guest tasting.

Match the pilot's process to the main system where you can: the same mash method, the same type of heating if possible and the same yeast handling. The more the two behave alike, the less you have to correct when scaling up.

What changes when you scale up

Recipes rarely transfer one to one. The usual adjustments:

• Efficiency. Mash efficiency often differs between systems. Measure it on both and scale the grain bill so the original gravity matches.
• Hop utilisation. Larger kettles hold heat longer after the boil, so whirlpool hops extract more bitterness. Late additions often need trimming at full scale.
• Boil-off. Evaporation rates differ. Measure them and adjust pre-boil volume.
• Fermentation heat. A large tank holds heat. Small fermenters lose it. Control temperature on both and log it.

Keep a scaling log for every beer that moves from pilot to main system: the pilot figures, the full-scale figures and the corrections. After a few brews you will know your own conversion factors. Our guide on planning a brewing schedule for eight taps shows where pilot brews fit in a busy week.

Licensing and excise

In India, beer brewed for sale is under excise control. Pilot batches are beer too. Depending on the state, a pilot system may need to be included in your licensed equipment, its batches recorded in the excise register and duty paid on what you serve. Rules vary by state and change, so ask your licensing adviser before you buy. Adding a vessel after the licence is issued may need an amendment.

If you plan to serve pilot beers to guests as tasting flights, confirm that this is allowed under your licence and how it must be recorded.

Use guests as your panel, carefully

A brewpub has an advantage that a production brewery does not: guests at the bar every night. A small pour of a pilot beer with a short card asking for a score gives quick feedback. Keep the pour small and free or cheap. The aim is an opinion, not extra drinking.

Treat the feedback with care. Guests who already love hazy IPAs will vote for a hazy IPA. Pair guest scores with a staff panel that tastes blind and records off-flavours, so you catch faults that a friendly crowd would forgive.

A first step before you buy

Before ordering equipment, write down the next six beers you would test and what question each test would answer. If you cannot list six, a pilot system is probably not your bottleneck yet. If you can, price the system against the cost of one failed full batch.

Think about the tank space as well as the brewhouse. A 50 litre batch still needs a small fermenter for two to four weeks and somewhere cold to condition. Three or four small jacketed fermenters on the glycol loop let you run tests side by side, for example the same wort split between two yeasts. That kind of split batch is where a pilot system teaches the most.

The Brewery Business Management course covers equipment decisions, capacity planning and the costing behind them. Your first step needs no course: write the list of six tests tonight and see whether it fills a page.

Common questions

What size pilot system suits a brewpub?

Many brewpubs choose 50 to 100 litres, enough to fill a keg or two and close enough to full scale for results to transfer.

Do pilot batches need an excise licence?

Beer brewed for sale is under excise control in India. Pilot batches are beer too. Check with your licensing adviser how your state treats them.

Why does a pilot recipe taste different at full scale?

Efficiency, hop utilisation, boil-off and fermentation heat all change with batch size. Keep a scaling log to learn your own corrections.