Cheese production step by step
• Click on any image to start slideshow
Photography: Geoff Pagotto.
More than a quarter of the 13bn litres of raw milk produced in the UK each year goes into cheese production; almost 360,000t was made last year.
Cheddar accounts for by far the biggest type (65% of production), with the remainder being made up of “territorials” such as Red Leicester and Double Gloucester (11% together), blue veins and other types.
Several processors make cheese, but Milk Link is the UK’s largest, producing a range of products for retail, food service and ingredients sectors. Farmers Weekly went along to one of the co-op’s members in Devon to find out more about the cheese-making process.
The milk producer
Darren Furse (picture 1 in gallery) is the fifth generation to run the dairy herd at Westcott Farm, near Holsworthy, which has been supplying Milk Link since the co-operative was formed from the break-up of Milk Marque.
At 30 years old, he is the youngest member of the Milk Link Council and also sits on the steering group for the Sainsbury’s Cheese Development Group.
Milk yields average 9000 litres a cow a year across the 220-cow herd, producing an annual milk supply of some 1.9m litres for the Taw Valley Creamery, 30 miles away. The farm has just switched to Milk Link’s seasonality contract and received an average price of 24p/litre in July.
Mr Furse believes working closely with end-users is the way the industry should go. “Whoever you’re supplying, it’s good to get closer to the end product and feel part of it. The closer we can get to the end of the supply chain, hopefully the more stability we can get in the end price,” he says.
Being part of the SCDG is a demonstration of that attitude and he believes it has helped improve profitability of the farm business. “There is pressure to increase welfare standards but, at the end of the day, that’s tied to profitability.”
An example of this is the decision to stop growing maize for silage this year, due to serious starling problems causing hygiene concerns. “We couldn’t keep the birds out of the forage or the sheds without compromising cow welfare, so decided the best thing to do was to stop growing maize altogether.” He is now focussing on maintaining yields and milk quality from the simplified grass-based system.
Milk quality is also one of the top priorities for Brian Kerr, head of operations at Taw Valley Creamery. The site processes 1.1m litres of milk a day, equivalent to around 35% of milk produced annually in Devon. “We manufacture 32,000t of cheese a year and our customers demand consistent quality and supply. When you’re producing cheese on a large scale, and have maturation times for some cheeses of 12-14 months, you’ve got to get it right first time.”
Balancing the fat and protein content of the raw milk is crucial to getting consistent cheese quality and is a particular issue during the spring flush. “I have to get as much as possible of that fat and protein into the cheese blocks, rather than losing it as a waste product,” he says. “We have to be flexible with our cheese recipes depending on how milk quality fluctuates.”
The cheese production process
• Some 40-55 tankers deliver milk to the Taw Valley Creamery every day. Each load is weighed and tested for quality and antibiotics – this can be cross-checked with the bulk tank sample taken on-farm. Milk is then transferred to one of the holding tanks, before tankers are washed and weighed out. It is kept at a constant 5C to preserve quality and sampled again before being released into the processing system.
• All milk is pasteurised before entering the cheese vats. At Taw Valley, this involves heating milk to 74C for a brief period (typically 26 seconds). Milk flows through the pasteuriser at 50,000 litres/min, into one of 10 different 20,000-litre vats.
• The vats are where cheese curd is formed. Milk is cooled to 32C, then specific starter cultures, rennet and colourings (if required) are added. The bacterial cultures ripen the milk and give it flavour and aroma later, while rennet helps milk coagulate and turns it into curd and whey. Exact recipes vary depending on what cheese is being made.
The milk is stirred twice in opposite directions and allowed to coagulate. Once curd has formed, it is then sliced up before everything is pumped out of the vat to the next stage.
Separation and conditioning
• A mechanical screen is used to separate the curd and whey. Curd is passed on to a moving table, where more liquid is drained. The whey is removed and converted to whey powder for commercial uses. Heat from the whey is recycled and used to heat up milk at the start of the process.
Curd then goes into a conditioning tower where it is compressed under its own weight for a set period of time, depending on the recipe. This conditioning allows acidity to build up, giving the resulting cheese its own characteristics – mature cheeses generally have higher acidity but, if it is too high, taste is compromised and the curd may crumble too much. The acidity can be controlled by altering the flow rate of curd through the tower and tables.
Next the curd is cut up again and passed onto a second table where salt is added (about 1.7% salt by weight). Ultrasonics are used to measure the depth of curd on the table and vary salt rates accordingly.
Block forming and wrapping
• Curd is vacuum pumped from table two into one of the five 16m-high block-forming towers. Here it is mechanically pressed into 20kg blocks – the amount of force varies depending on individual cheese recipes.
Blocks are vacuum wrapped in plastic and passed through a metal detector and then a separate camera to check the bags are sealed properly. Each is labelled with its own batch number and can potentially be traced back to the farm where the milk came from within 30 minutes, Mr Kerr says.
Each plastic-wrapped block is then packaged in a cardboard box to protect it from damage.
Chilling and maturation
• The boxed cheese blocks are chilled (typically at 6-8C for 11 hours, depending on recipe) before being wrapped on a pallet and moved to store. The whole process from pasteurisation to chill store takes around 4.5 hours and is done in batches of a particular recipe.
During maturation the cultures in the cheese knit the curds together, which together with the acidity, give the cheese its own flavour and texture. Maturation times vary from one to five months for mild cheddar to nearer 12-14 months for extra mature cheeses.
Packing and distribution
• Once cheese has matured for the desired period, it is removed from store, de-boxed and sent to Milk Link’s purpose-built plant in Oswestry where it is cut, packed and distributed to end-users.