Skipper and First Mate Millard (Big Bear and Pepe)
Mon 28 Jul 2014 22:57
Our Speight’s Brewery Tour
We finished the museum part of our tour in a room filled with awards and medals. We particularly loved the gallery of vehicles used to transport the beer around the country.
Beer begins with great quality water so we began the brewery bit of our tour in the water room. Speight’s brewery is very conveniently built over its own bore of natural spring water. They have been using this natural mineral rich water for their famous brew for well over a hundred years. The spring water is pumped from the bore and stored in ‘Copper 2’, from there it is both sand and activated carbon filtered just to ensure it contains no impurities, before being stored in ‘Copper 1’. This water is then used directly in brewing.
The original flooring and wall tiles are listed, many had to be removed to enable the earthquake support walls to be added on the inner walls. The company used this as an opportunity to bring in people with learning difficulties. They set to work in a very dedicated and patient way. The removed tiles were cleaned and replaced, just as they were.
There’s an art to brewing a good beer, the best natural raw ingredients with a bit of science thrown in for good measure. The brew is then lovingly crafted through a carefully controlled brewing process. The result is an outstanding drop. The raw materials used at Speight’s are malted barley, sugar, hops yeast and of course the above mentioned water. The barley is grown throughout South Island and the Manawatu Plains on North Island, gathered and malted ready for use. Specialty malts, such as crystal, amber, black caramalt and wheat malt are either found in New Zealand or brought in from Australia and the UK. Prime New Zealand hops grown in the Nelson District are used to give the essential bitterness and aroma, the hallmarks of a good beer. Yeast, although not strictly an ingredient, plays its part by converting the raw materials into beer.
Bear showing an original hop collecting basket, in the days it was all done by hand. What you cannot see in the picture is this enormous basket is really heavy to begin with. The machine where the hops enter the brewing system and the trusty hop.
Growing up in Kent, it was very difficult to go too far before you were looking at miles of hop fields, then owned by Whitbread and some by Guinness. Hops, when mentioned can go a bit Latin and a bit sciency. The good old hop belongs to a small botanical family Cannabinacae, comprising only two genres – Humulus and Cannibis. No funny ideas though, not that stuff. Humulus is represented by two species the common hop - humulus lupulis and the Japanese hop – humulis japonicas. The genus Cannibis is solely represented by the hemp – cannibis sativa.
The hop is a hardy bugger - not a swear word in these parts and used as a direct quote, as above. It’s an herbaceous climbing plant that started off in Europe and Western Asia. The dried cones contain lupulin, an aromatic, bittering compound that has been used for centuries in beer making.
The New Zealand Hop Industry has been running specialised plant breeding since the 1950’s. In 1968 New Zealand made headlines in brewing circles. In response to international brewers’ demand for seedless hops, the first country to commercially produce hops from triploid hop cultivars. These cultivars lead the world in high alpha acid content together with favourable characteristics.
Harvesting: In Nelson, harvest time is from late February to early March, every year. After cutting, the hop vines are brought to the picking machines, where the mature hop cones are stripped from the vines, and put through a series of cleaning belts to remove leaves and remnants of vine. Hop cones are dried through a combination of flat bed drying and multi-floor kilns. The bulk of them are processed into pellets, vacuum packed, then cooled stored until delivery to the brewery. That way they are kept fresh.
Each batch of malt is weighed and cleaned on the way up to the malt mill. Then just before a ‘brew’ begins its crushed to form the ‘grist’. The usual batch size is around three tonnes and needs to be crushed within a forty five minute window. The crushed malt ‘grist’ sits in the grist case before mashing takes place. Safety first, historically, mills have been positioned against exterior walls as a precaution against malt dust explosion........
This lovely lady was built by G.J. Worssam & Son in London and still working as good as new.
The Brew Floor. The malt grist is combined with warm water on the way to the mash mixer, through a “Steels Masher”. The result is a porridge like mixture called “the mash”. The naturally occurring enzymes from the malt then convert the malt starch into sugars, mainly maltose. This process takes approximately two hours during which time the temperature is increased from the initial forty five degrees to seventy five degrees Centigrade. After completion of mashing all starch will have been converted to sugars. This is checked using the iodine starch test. The mash is then transferred to the lauter.
The lauter is used to separate the dissolved sugars from the insoluble remnants of the malt. The dissolved sugars are known as “the wort”. Wort is run off the bottom of the lauter through the malt husks and collected into the kettle. Hot water, also known as “hot liquor”, is sprayed onto the top of the mash to rinse the sugars through. The malt husks retained in the lauter are removed and used as cattle feed. Lautering takes two to three hours.
The wort from the lauter is collected into the kettle over a period of two to three hours. The volume of wort collected is twenty four thousand litres at double strength. Wort is then boiled for ninety minutes. During the boil, sugars and hops are added. The boiling process performs several important functions:
Sterilisation of the wort.
Added sugars are dissolved.
Many flavour enhancing reactions take place. Flavanoid formation and caramelisation occurs.
The hops added increase in bitterness.
Protein out of the original malt separates into flocs.
The malt enzymes are inactivated.
The cooker is used as a holding vessel for wort collecting from the days second brew, while the first brew is still boiling in the kettle. It was originally installed to process – “cook” other cereals such as rice, which can be used as a source of starch.
There is another separation vessel. The boiling wort from the kettle is rapidly transferred to the whirlpool in such a way that the hot wort circulates. This circulation causes the “whirlpool effect” where protein flocs formed in the kettle, settle to the base of the vessel.
We moved from the traditional to the new, sparkling stainless steel. Quicker, computer operated but not as handsome.
Yeast is added to the wort which converts the sugars into alcohol and carbon dioxide. The fermentation takes about seven days to produce ‘green’ or unmatured beer. Towards the end of fermentation yeast begins to settle to the bottom of the vessel. Once fermentation is complete, the fermenter is cooled down to two degrees Centigrade prior to the beer being transferred to the maturation tanks. All the carbon dioxide produced is collected and reused at filtration to provide the carbonation in the beer. The beer is cooled to zero. Dissolved carbon dioxide is allowed to vent off the tanks, taking unpleasant sulphury compounds produced during fermentation with it. Any yeast left will settle, these two processes help get rid of the “green” flavour and allow easier filtration. Beer is then typically stored between one to four weeks, depending on type.
Once the beer is matured, its filtered. At Speight’s distomaceous earth is used in a vertical leaf bowser filter of sand or diatom shells. The filter earth is deposited onto a wire mesh support, which the beer is then passed through, on its way to the finished beer tank - “bright beer” that is clear and sparkling and ready for racking into kegs.
Tasting time. How much do they make - Twenty four million litres a year flow from this plant.
We bade our farewell and thank you. Outside it was getting toward dusk. The bridge was lit up, the last tour of the day assembled. We watched for a while and saw many people come to fill all kinds of containers from the complementary tap – sadly just bore water......... We’ll close with our favourite advertisement – customer parking only.
ALL IN ALL FASCINATING TO SEE OLD AND NEW WORKING