Arthur Guinness Park Royal. Brewing School visits 1968 to 1969

Guinness (Park Royal) Brewery

Visit by Brewing School students in January 1969

A large brewery on an open site built in 1935. Extra stout only is produced at five to six thousand barrels per day maximum. Metropolitan Water Board water is nearest in composition to County Kilkenny wells; this fact as well as distribution economics sited the brewery here. Avoids packaging of product which is transferred out by bulk tanker for bottling.

Concrete silos contain 18,750 tons of barley and malt . The grist contains 72% pale malt ,8% roast barley and 20% flaked barley which is produced by steaming and rollering. Waste on malt screen should not exceed one and a half percent. Maximum moisture of 3.4% allowed and malt is blended according to lab results. Hops are Bullion, Northern Brewer, Fuggles, Bramling Cross, College Cluster, Keyworth Mid-season.

Barley is roasted in oil heated drums.

There is one large mash each day. There are eight weighers, eight mils, eight kieves of 250 barrel capacity but one new one is 360. There is an 80 inch mash depth. Feeds four 600 barrel coppers. Small worts are used for mashing in (30%).

The mash starts at 3:30 a.m. there is a one hour stand, run off all eight mash tuns into one under back at 22 barrels per hour. Run off is finished by 12 noon. Copper boils out 30 barrels from 600 and they collect 520. There are three boils in each copper without emptying spent hops. 33% of total hops added to the first boil and the rest is divided between the next two boils and this gives good utilisation. At 5:00 p.m. the run starts into fermenter and the whole brew is finished by 4:30 am the following morning.

Wort is broken down to 1044.8 or 1039.8 if a keg product. There are 13 fermenters up to 1550 barrels and these take 12 hours to fill. Fermentation starts at 63oF with a half pound per barrel pitching rate. There is no attemperation and the temperature may reach 80^oF. Fermentation last 53 hours before the beer is centrifuged. Yeast is pressed and if the viability is greater than 86% it is used again. The yeast is recultured every two months. FVs are cleaned with Powerbright and steamed but not under pressure. All CO² from fermentation is collected and used in the brewery. Beer is centrifuged to conditioning.

Three brews are always blended to give the final product, but never more than 50% of one of them.

Keg beer is pasteurised at 190°F for 40 seconds. Tankers are washed and steamed at 20 psi for 20 minutes. Kegs cost 15 pounds each and last seven to ten years but some find their way to scrap merchants before then! CO²/nitrogen 1/3 to 2/3 dispense at 20 PSI which gives a less harsh taste and a creamier head.

There is a Dawson washer with 160°F pre-rinse 180°F hot rinse and 200°F final rinse then four steam jets. There are 16 racking heads with a 60 second fill. 14 men fill 480 kegs per hour which totals some 40,000 kegs per week.

The brewhouse is open plan it's easy to remove equipment but of course one product eases all production problems. Tower fermentation was found unsuitable for Extra Stout. With so much equipment even though a huge amount of wort is handled every day a single brew every 24 hours must represent poor plant utilisation.