The craft of brewing

Marston’s PLC, the UK brewing and pub retailer, operates around 2,100 pubs and bars across the UK, as well as producing premium cask and bottled ales, with over 60 beers brewed at their five sites, which includes Bank’s Brewery in Wolverhampton, Jennings Brewery in the Lake District, Ringwood Brewery in Hampshire, Wychwood Brewery in Oxfordshire, and Marston’s Brewery in Burton Upon Trent. 

The Burton upon Trent brewery has been established since 1834 in the spiritual home of British brewing, thanks to the spring water from Trent Valley.  Burton’s sulphate-rich water has a unique taste and flavour that Marston’s has used in its Pedigree beer to this day. 

In 2005, the Marston’s Brewhouse was updated, and almost everything is stainless steel. A four roller mill grinds the barley, which has been germinated, dried and roasted. “If you roast at a low temperature, you get fudge, which is a light malt,” explains Colin Walton, Senior Engineer at Marston’s Brewery. “Or if you roast at a high temperature, you get treacle toffee, or a dark malt.” The barley husks fall apart and the smaller pieces are then are mixed with heated Burton well water from the brewery fields in a masher, where natural enzymes break the starches down into sugars. Different malts, different temperatures and different waters used strongly influence the resulting beer. 

The sugars run through the plates, leaving spent grain behind which is then used for cattle feed. “We don’t waste anything,” Walton says. “Everything is used, or reused in the process.”  The wort, as the liquid is now called, transfers to a ‘copper’ kettle, named from the material the kettles used to be manufactured from, although they are now made with stainless steel. Hops are added, which is where beer gets it’s bitterness from, and they are boiled in one of three copper kettles at Marston’s, which can hold up to 44,000 litres each.  Large steam boilers boil off 10% of the liquid in the coppers, with flames reaching 20 feet.

The wort is then pumped into a whirlpool, where trub, which can cause off-flavours in the finished beer, is removed in a process where the liquid is circulated in a teacup effect that forces the denser solids towards the centre of the tank and drops down into the conical bottom, to be used for compost and the wort is rapidly cooled using a heat exchanger, ready for fermentation. The heat drawn from the wort is then used to heat the water for the next batch to be mashed. Yeast is then added to the wort, which converts the sugars from the malt to alcohol and carbon dioxide during fermentation, and becomes beer. When the sugars have been almost entirely digested, the yeast settles toward the bottom of the tank. The yeast is then filtered out, unless it is going into the casks, where fermentation continues until the yeast rises through a swan neck on the top, which separates the beer from the yeast. 

“We do use a lot of water here,” Walton says. “Beer itself is mostly composed of water. For every barrel of beer that we brew, we use another six barrels-worth of water to clean the pipes and clean the tanks. But we operate in an environmentally responsible way and we’re committed to supporting environmental sustainability. This site, and the Wolverhampton Brewery, has to comply with the Integrated Pollution Prevention and Control standards, regulated by the Environmental Agency. It’s an integrated approach to control the environmental impacts of certain industrial activities.”

The real investment Marston’s have made in the past year is their new £7.4 million bottling line. The company now runs two bottling production lines, one installed in the late 1990s and still running. It’s a 500 bottles per minute (bpm) cold fill line based around a KHS filler, Krones pasteuriser, Kosme Labeller, Kister packer and ACMI palletiser, known as Line A. 

Line B is a state-of-the-art KHS glass filling line, designed specifically to fill Marston’s own beers and contract customers’ ales at 16°C, running at 300 bpm, with bottle sizes ranging from 275, 330, 500 and 660ml. The line can run 18,000 bottles every hour with either flash pasteurisation or sterile filtration and has been installed as a turnkey operation.

When filling beer, absolutely sterile and hygienic filtration, precise dosing accuracy and reliable stabilisation are incredibly important. 

The new bottling line enables Marston’s to keep up with the growth in their bottled beer production. The Burton upon Trent site bottles beers from all five of Marston’s breweries and sterile filtration allows the company to bring in-house all of its previously contract packaged bottle-conditioned brands. Empty bottles are fed down slotted conveyors where they are washed and sterilised before filling with beer, after which they are sealed and three labels (front, back and bottleneck) are applied. The bottles are then fed through a tray and shrink wrap machine, the fully automated Innopack Kisters TSP. A KHS / KUKA robot collects the trays and palletises them, before they’re stored in the warehouse or shipped out for delivery.

The new bottling line runs quietly, thanks to its variable speed drives and design. “When you’ve got a warehouse as busy as ours, you don’t want more than a months’ worth of stock of everything,” Walton explains. “So you end up planning to process up to six beers every day, with varying bottle sizes. You can try and plan to process all the beers in one size of bottle, and then all the beers in another size of bottle, but it’s not always possible. Sometimes you might have a beer change and a bottle change, as well as a label change, and so forth. As nice as it would be to run Pedigree beer for 15 days of the month and Hobgoblin beer for the next 15 days, it’s just not possible. So the new line makes it easier to change, reducing downtime and improving efficiency.”

“We are very much driven by what the supermarket demands,” says Walton. “The British Retail Consortium audit Marston’s, making sure that everything is up to standard. We also have Marks and Spencer and Waitrose audits, and The Soil Association, who audit our organic beers. We also have audits from Lidl and Aldi. So we’re well-audited and of course our procedures meet standards.”