Case study: Siemens ‘ferment’ change for Dorset family brewery
17 Apr 2017
Siemens know-how enabled a family brewer to improve its fermentation process while maintaining its traditions.
Founded in 1794, family-run Palmers Brewery in Dorset is one of the oldest independent beer manufacturers in the UK.
Its premises are also unusual, consisting of a thatched tower building containing a brewing kit with open- topped copper dating back to the 19th century.
However, Palmers faced a challenge combining its long-term focus on making distinctive flavours for its fine ales with achieving greater accuracy during the fermentation process – where consistent temperatures and repeatability are vital.
We were looking to modernise to a more accurate and reliable system, with the added benefits of freeing up some of the time we were spending doing these checks and adjustments
Darren Batten, head brewer, Palmers Brewery
Fermentation governs how much alcohol ends up in the end product, with duty rising according to alcoholic strength. Ambient temperatures can vary too, adding to the consistency challenge.
Head brewer Darren Batten explains the challenge: “The old system featured diaphragm valves, which had to be manually checked. We were looking to modernise to a more accurate and reliable system, with the added benefits of freeing up some of the time we were spending doing these checks and adjustments.”
Charged with improving the efficiency of the brewhouse through investment in future-proof technologies, Batten turned to Siemens to see how temperature control could be made even more accurate and time-consuming manual control could be reduced.
Sara Nichols, Siemens account development manager, adds: “The pinchpoint is the fermentation part of the brewing process as fermentation generates heat. Too much cooling stops the fermentation, so keeping accurate and consistent control at this stage has a significant impact on consistency and quality.
“It is this part of the process that will challenge the brewer the most for repeatability, to keep the alcohol levels within certain parameters and the brew consistent. So, by closely controlling this area, consistency can be assured.”
Too much cooling stops the fermentation, so keeping accurate and consistent control at this stage has a significant impact on consistency and quality
Sara Nichols, Siemens account development manager
Siemens’ Simatic S7-1200 PLC fully controls temperature during the fermentation section, and provides the ability to run a profile – for example, a controlled temperature rise and a specified hold time at a top fermentation temperature. For the final part of the process, temperatures are dropped by around 15°C to stabilise and condition the brew.
The 1200 can be viewed or adjusted from anywhere in the plant, which standalone controllers cannot do. So, when ambient temperatures vary in the winter and summer months, it can be programmed to incorporate cooling capabilities, such as running mains water round a tank.
At Palmers, fermentation in the traditional open top vessels is year-round, requiring a value-for-money control option. The Simatic S7-1200 has been successfully operating for six months.
The new system features a percentage opening of a rotary ball valve, which is much simpler, says Batten, plus more reliable and recipe based.
The modular Simatic P7-1200 PLC also fits with the total integrated automation (TIA) portal, working with HMI, I/Os, drives and software, and can be controlled from a smartphone, says Siemens.