Curd perfect

Related tags Cheese

Me & my factory: Mandy Kitchingman, Factory Manager, Dairy Crest - Hartington Creamery

This will be my first Christmas at Hartington Creamery. Manufacturing volumes have increased from August, and it's been flat out since October because of the seasonal demand. We predominantly manufacture Stilton, which is a protected product and can only be manufactured in three English counties. There are a few producers in Leicestershire and Nottinghamshire, but we're the only one in Derbyshire.

Before 2001 there were just 12 vats of Stilton being made here daily, in the traditional way. Then Dairy Crest invested in an automated coagulation plant. It's a continuous, linear process where the curds and whey move slowly along a single, long vat, which replicates the way we manufacture traditionally in open vats.

In coagulation, the milk is acting with the other ingredients -- a starter culture, rennet, and mould -- to form the curds. The milk fat and the proteins bind together, and as the curd forms we cut channels into it, using thin wires, so that the whey drains away. It's a critical process: you don't want the whey to drain off too quickly, and you don't want to damage the curd as this all affects the quality and yield.

Coagulation takes about two-and-a-half hours, and whether it happens in traditional open vats or on the automatic coagulator, there's no corner-cutting in terms of time, otherwise we'd be working outside the protected designation of origin (PDO) and we couldn't call the product Stilton.

When the coagulator was installed the original vat room was almost redundant. However, some customers prefer us to use the old methods of manufacturing. To put it in perspective, there's a team of six or seven employees in the vat room, four days a week. The coagulator manufactures 110,000-115,000 litres a day, seven days a week, and there are two people operating the plant plus a supervisor at any one time.

Coagulator and the vat room manufacture are like different factories on different shift patterns with differing sets of skills. The coagulator is highly automated and a PC- driven plant, however the people who operate this still need cheese-making skills. It's clearly a more technical role than that of traditional cheese-making, which is still a 'bit of a black art'!

Hartington differs from a typical Cheddar plant. They'd manufacture the cheese, send it to another site for maturation and storage, and then on to another for cutting and packing. We are different, because we're dealing with a blue cheese. One of the ingredients is mould, and we wouldn't want the mould spores to affect other products, so we manufacture, mature and cut and pack the cheese all on one site.

Our process is also much quicker. Maturation takes something between nine and 12 weeks for Stilton; with Cheddar it can be anything up to two years.

We also make Dovedale, which is a soft blue cheese that was created here about 10 years ago. We make a white Stilton, which goes through the same Stilton process, minus the mould. And then we've got what we call a 'blended' factory. We blend cheeses with other ingredients for example Stilton and Apricot or Wensleydale and Cranberry. This again is a factory within a factory. New product development is a large driving force behind 'blended' manufacture.

Pre-packing is a separate operation, where Mike Davies is the factory manager. Obviously manufacturing and packing go hand in glove -- pre-pack is my customer, so it's imperative that I supply them with the right quality. Both areas have their points of expertise.

After coagulation, we move the curds to primary drainage, where the rest of the whey drains away. In the vat room, we just transfer the curds by gravity from one set of vats to another, where they drain overnight. In the coagulator plant, the curds are filled into cylindrical plastic 'hoops' about 30cm in diameter, and they move along a track for 21 hours while they drain. They're also turned mechanically after five hours and 18 hours, again to replicate the vat room manufacture, which is all turned by hand.

We then mill the curd, chopping it into small pieces until it looks a bit like scrambled egg. We add salt, which is all to do with moisture levels, acidity, flavour and preservation; and then we fill the curd into hoops again, where they're formed into cheeses. There are various sizes, but we mostly fill 10kg hoops. Again, it's done by hand in the vat room operation, but the curds from the coagulator are filled through a multi-head weigher.

The cheese goes through 'hastening', which is a four-day process where the curds bind together, then it's de-boxed, or taken out of the hoops, and then we 'bind' it traditionally, by hand. That golden coat you see on the outside of Stilton is the result of binding. We use a palette knife dipped in water and run it backwards and forwards over the outside of the cheese -- a bit like smoothing plaster -- to create a seal. That stops the air penetrating, so we can control the mould growth. Binding is still hard work, so we've introduced some automation to help with the first stage. But every cheese is finished by hand.

We let the cheese develop in our maturation stores for up to five weeks before we pierce it to let the oxygen in, and that lets the mould grow. Moulds are very delicate, really. If you mature the cheese too quickly they just grow very rapidly and then die and a secondary mould may grow, giving the cheese a bitter taste profile.

Every day that goes by, the Stilton is changing, so we're grading every cheese regularly from the time it goes into maturation. That's an art in itself. The grader has to really understand flavours and texture profiles for each individual customer. Our technical manager John Etherington has a wealth of experience and can help our graders if there is something that's a bit quirky.

In manufacturing, there are so many things that can affect the overall flavour, consistency and texture. For example, there's the 'winter to summer' variation, depending on whether the cows are eating grass or hay, which means you get different fat or protein levels. And we're taking milk from different herds in three different counties. Some dairies standardise their milk before they use it. We don't, so our product will always be slightly different.

We measure yield at two stages. First we have 'green yield', which is how much milk we put in and how much curd we get out. Every time you touch the curd it can affect the fat and protein content and the whey drainage, so it's critical you don't over-work the cheese.

Then, once the cheese is made, we have the final 'cheese stores' yield, where we measure the weight of the cheese before going into the pre-pack operation.

I joined Dairy Crest in late February -- before that I spent 20 years with Northern Foods -- and my biggest challenge since arriving has been recruitment and retention. Logistically, we're very difficult to get to -- we're in a picturesque village, 10 miles from the nearest town.

We're looking at what else we can offer, like better facilities to work in, and we are investing in training. We're running courses in manufacturing process improvement -- equivalent to a Certificate/Diploma in management studies -- with the University of Birmingham. And the next thing we're pursuing is Modern Apprenticeships.

I have gone through a large learning curve, as the site did when the coagulator was first installed. The quality did suffer. The problems with a two-and-a-half-hour linear process come when you get a breakdown, because the entire system is affected. What happens if there's a five-minute stoppage, or a 30-minute stoppage, or if the blades that automatically cut the curd go blunt? Understanding all those parameters was a massive learning curve for the team at Hartington. But the inconsistencies are finally being ironed out now, and this year we've been stealing all the shows -- including a Gold in the World Cheese Awards.

Interview by Mick Whitworth

Personal

Name: Mandy Kitchingman

Age: 36

Career highlights: Joined Northern Foods at 16 as a YTS trainee, and spent first 14 years at Fox's Biscuits in Batley in a number of roles. Moved to Christmas pudding manufacturer Matthew Walker's for four years, and then on to Park Cakes in Oldham for two years before joining Dairy Crest February 2004.

Domestics: Renting a house locally while she waits to sell her house in the Pennines. Any offers?!

Outside work: Loves to travel -- she's been to Barcelona, Rome, Kenya and Mauritius this year -- and keeps fit by walking her dog in the Derbyshire dales.