Installation, Testing, Calibration & Commissioning

The first of these things is installation. This is the obvious one, so I won’t spend too much time on it. When any equipment arrives, you have install it in some way before you can use it. This might be as simple as setting it on a desk or plugging it into the socket on the wall but for a whole brewery there are a few more bits to it. Overall, it is quite straight forward and essentially a big 3D jigsaw. However, it is important to not overlook things. For example, the correct nuts, bolts, gaskets etc. should be used to prevent failure or an accident causing injury or worse.

To get everything up and running in the brewery it is important to test things as you go. One good example is the chiller unit which cools the fermentation tanks. Once the cooling circuit has been constructed you should test it to ensure that there are no leaks and it holds the desired pressure before running the compressor, before adding any glycol and before adding pipe lagging. If this testing step is skipped and you do have a leak it will be much harder to fix as it won’t be known until later. The location of the leak will probably be covered up so you will have to remove a load of insulation to look for it and even then, the circuit will likely be cold and will form condensation making it very hard to find.

Ironically, I didn’t even follow my own advice here. We filled the thermal fluid system before leak testing. We did this for the exact reason above – time pressures. We needed to book a commissioning slot in a few weeks in advance when we hadn’t even done the pipework for it. We had only just finished assembling it the day of and didn’t have time to do the leak test before the committed date. We were so short on time that we were filling it during the start of commissioning! Guess what, it leaked. It leaked quite significantly, and we couldn’t resolve it during commissioning, so it had to be redone – all gaskets replaced and commissioning rebooked. Not only did trying to squeeze this in by skipping a step not save me any time it actually added more time as it took around a week of full-time effort to resolve the leak issue.

Calibration is an area that doesn’t get anywhere near enough attention in small breweries as it should. It is a way of making sure the instrumentation outputs data with an acceptable level of uncertainty for the application. In breweries there are many parameters which are important and measured at various points. These measured values are used to make key decisions and to ensure the beer is in spec (and in some cases safe to drink!) so it is very important the device outputting this data is calibrated.

Take temperature for example. If a beer is to be fermented at 19°C or the mash is supposed to be at 65°C what do you do? Most people/systems look at the temperature probe readout and manipulate the process to get the 19°C or the 65°C they need. But how do you know that this 19°C or 65°C you are looking at on the readout is correct? Do you just think ”that’s what it says so it must be right”? Well a lot of people do exactly this and a lot of the time the readout is wrong. The reason for this is that it either isn’t calibrated or the results of any calibration that has been done isn’t known. Depending on the instrumentation used to measure the temperature the error can be several degrees Celsius, this difference can cause unacceptable changes to the intended beer. In the fermentation tank it can be the difference between healthy and unhealthy fermentation, it can also lead to fusel alcohols, diacetyl and other off flavors. In the mash it can be the difference between light and full body in the finished beer or over or under attenuation. Here it is clear that we need a certain level of accuracy to make sure that we are not a few degrees out from what we think the temperature is. To do this the instrument needs to be calibrated. There are simple crude methods to do this such as putting the probe in boiling water and making sure it reads 100°C and then into ice water and making sure it reads 0°C however this isn’t very accurate, the calibrated output range here is 0-100°C and you are assuming that it is linear (I have used this method in the past). The operating range for most temperature measurements in brewing is far smaller than the 100 degrees range so a better way is to take more than two carefully selected calibration points. One at the bottom, one at the top and one or more in the middle. If you never go hotter than 25°C and colder than -1°C then this is the range you should calibrate in. This is a more complicated process (and also more complex than my simple explanation here) so it needs specialist equipment and processes. Normally a small business won’t do this themselves, they will send it off to a United Kingdom Accreditation Service (UKAS) accredited lab. There is a cost involved but if you want to be sure that the measurements you are using to make your product are accurate then this is really the only safe way.

This is the final step before you can get up and running. It is a way of confirming that the system (or subsystem) operates how you expect it to. E.g. when you press the “lauter pump on” button that the lauter pump actually comes on. When you set the speed of that pump to 30L/min that it actually runs at 30L/min. Or when you set the cooling jacket to come on above 2°C and go off again at 0°C that this actually happens. For large plants then a full commissioning plan should be created and followed which is an extensive bit of work. However if you have a relatively simple plant (e.g. minimal or no automation) then you can probably cover all of this by running the system in all the ways you would do normally, e.g. wort production and transfer, cooling though the heat exchanger, running the CIP cycle etc. You can do this with only water the first time around which should catch most of the issues. Once you are happy that you can do everything as expected with the water then you can do a commissioning brew, which is what I have done. In the past I have done this with older stock because there is a good chance the beer would be going down the drain anyway. This time around I had to do it with regular stock as I have some equipment that can’t be commissioned unless the beer is made as intended. It is an expensive step but I believe in this instance it is a sensible step as the entire plant and all auxiliary equipment is new so everything needs to be commissioned. If something didn’t work correctly on the production beers then things would be a whole lot worse.