Auditing a host brewery before the first contract batch

Go in with a checklist

An audit is a structured look at how the brewery works, not a tour. Agree a date with the host, send your checklist in advance and ask for documents to be ready. Plan to spend most of a working day there, including a brew in progress if you can.

Score each area simply: good, needs work or unacceptable. Ask for evidence rather than reassurance. A record you can see counts. A promise does not.

Cleaning and hygiene

Ask for cleaning in place (CIP) records for the last month. Each clean should log the chemicals used, concentration, temperature and time. A typical hot caustic clean runs at around 1.5 to 2% caustic at 70 to 80 °C. You do not need to memorise numbers. You need to see that the brewery records them every time.

Look at the cellar floor, drains, hoses and gaskets. Hoses lying on a wet floor and cracked gaskets are where bacteria live. Ask how the brewery verifies cleaning, for example with ATP swabs or plating. Check how the brewery handles pests and broken glass, especially near the packaging line.

The lab and the numbers

A host does not need a big lab, but it does need the basics: gravity, pH, temperature, carbonation and dissolved oxygen, plus some microbiological testing. Ask to see the results for its own beers over the last few months. Look for consistency. A pale lager whose final gravity wanders from batch to batch suggests fermentation is not under control.

Check calibration. When was the pH meter last calibrated? Is there a log? A meter that reads 0.2 off makes every pH result useless. Our guide to the brewery QC lab on a budget shows what a small lab should cover.

Packaging and oxygen

Packaging is where most contract beer goes wrong. Watch a run on the canning or bottling line. Ask for dissolved oxygen readings in finished packs. Many craft breweries aim to keep packaged beer under 50 ppb. A brewery that cannot tell you its figure is guessing.

Check fill levels, seam checks on cans and torque checks on caps. Ask how often seams are measured and who signs off the records. Look at how finished stock is stored. Hoppy beer left in a warm warehouse in May will taste old within weeks, whatever happened on the line.

Records, traceability and recall

Every batch should carry a lot code that links the packaged beer back to its brew sheet, raw material lots and lab results. Pick a random pack from the warehouse and ask the host to trace it. A good brewery can do this in minutes.

Ask whether the host has ever run a mock recall. Ask how complaints are logged and answered. If your beer ever has a problem in the market, this is the system that decides how much stock you lose and how quickly you find the cause.

People and attitude

Talk to the brewers, not only the owner. Ask who will brew your beer and who you call when something goes wrong. A host whose team welcomes questions is usually a host that will tell you about a problem before you find it on a shelf.

Write your findings up within a day while they are fresh. Agree any fixes in writing before batch one. If the list of fixes is long, that is your answer. A founder who has never run a brewery often struggles to judge which gaps are normal and which are serious.

Raw materials and storage

Walk through the malt and hop stores. Malt should be dry, off the floor and protected from pests. In the Indian monsoon, open malt bags pick up moisture and go slack, which hurts milling and extract. Hops should be in a freezer or cold store, sealed in their foil packs, with lot numbers recorded against each brew.

Ask how the host would handle your own raw materials if you supply them. Are they stored separately and labelled with your brand? Who checks a delivery against your specification? A host that treats your malt as part of its general stock may swap it for its own without telling you.

Check the water too. Ask what treatment the brewing water gets and how often it is tested. Borewell water that changes through the year can change your beer with it.

Your first step

Before you book the visit, send the host a one page list of documents to have ready: a month of CIP logs, three months of lab results, ten packaging runs with oxygen readings, calibration records and the last complaint log. How it responds to that email is the first result of your audit.

Common questions

How long should a host brewery audit take?

Plan for most of a working day, ideally including a brew in progress and a packaging run.

What is a good dissolved oxygen level in packaged beer?

Many craft breweries aim for under 50 ppb in the finished pack. Lower is better, especially for hoppy beer.

Should I audit the host again later?

Yes. A repeat visit every six to twelve months and after any problem batch keeps standards from drifting.