Christmas can be one of the busiest periods of the year for a brewery. Orders need to leave on time, customers want enough beer in stock and everybody is trying to finish production before the holidays. Then, almost overnight, production can become very quiet for several days or even a few weeks.
Most breweries plan carefully how much beer needs to be brewed and packaged before Christmas. It is equally important to think about what will happen during the shutdown and what condition the brewery will be in when production starts again. Good Christmas planning should therefore include not only the last brew of December, but also the first brew of January.
Start your January planning before Christmas
A useful approach is to start with your first production week in January and work backwards. Consider which beers need to be ready, which fermenters need to be available and whether enough yeast and raw materials will be in stock. You should also identify which beers will remain in tanks during the break and whether they need additional checks before everybody leaves.
Beer does not stop changing because the brewery is closed. Yeast, enzymes and microorganisms can remain active, while fermentation or refermentation can continue during the holiday period. Before leaving, make sure that beer has really reached the process stage you expect by checking relevant parameters such as gravity, pH and fermentable sugars.
Dry-hopped beers deserve particular attention because of the possibility of hop creep. A beer that appears to have reached final gravity can receive new fermentable sugars as hop enzymes continue breaking down larger carbohydrates. If nobody checks the tank for ten days, the beer you find in January may be different from the beer you left before Christmas.
Do not leave cleaning for January
The period before a shutdown is also a good opportunity for deeper cleaning. During normal production, some areas receive less attention because there is always another batch, transfer or packaging run waiting. A planned shutdown creates time to inspect and clean equipment that can be difficult to access during continuous production.
Pay particular attention to hoses, gaskets, valves, sample ports, fillers, heat exchangers and other places where beer or wort can remain. Small product residues can provide nutrients for microorganisms, especially when equipment remains unused for a longer period. Biofilms can also develop in places that look perfectly clean from the outside.
Remember that cleaning and disinfection are two different steps. Organic material should first be removed properly, because sanitiser cannot compensate for poor cleaning. You should also think carefully about equipment that will remain wet, because standing water combined with product residues can create good conditions for microbial growth.
Think about yeast and microbiology
If you harvest and reuse yeast, decide before the shutdown what will happen to your culture. Consider how long it will be stored, under which conditions and what its condition is likely to be when you start brewing again. Before using stored yeast after a longer break, checking its quality and viability can prevent problems from entering the first January fermentation.
Sometimes starting again with fresh yeast is more practical than trying to preserve a culture through a long production break. The cost of a new pitch should be compared with the potential cost of slow fermentation, unwanted flavours or contamination affecting several batches. The correct decision will depend on your brewery, yeast management system and length of the shutdown.
A shutdown is also a useful moment to look at the microbiological condition of the brewery. If you already suspect contamination somewhere in the process, it is better to investigate it before the holidays rather than hoping it disappears during the break. Depending on the risk, laboratory testing can include wild yeast, lactic acid bacteria or specific organisms such as Saccharomyces cerevisiae var. diastaticus.
Make the first brew of January predictable
When you return, do not assume that everything will behave exactly as it did before the shutdown. Check critical systems before the first wort enters a fermenter, including cleaning systems, temperature control, gases and equipment that has been standing unused. Taking a little extra time during the restart is much cheaper than discovering a problem after the first tanks are already full.
The first fermentation can also provide useful information about whether the brewery has restarted correctly. Follow your normal QC parameters such as pH, gravity or fermentable sugars and compare the fermentation curve with previous batches. If something behaves differently, investigate early rather than waiting until packaging.
Good brewery planning is not only about keeping tanks full and making sure orders leave on time. Stopping production correctly is also part of process control, and a few additional hours spent on cleaning, checking beer stability and preparing yeast can prevent days of troubleshooting later. The question to ask before locking the brewery for Christmas is simple: what condition do we want to find it in when we return?