Cheese : Making Whey While the Sun Shines

I am delighted to welcome Paul Thomas, head Cheesemaker at Lyburn Farm. Lyburn Farm make a variety of hand made cheeses, all of which are made from their own cows milk. I have had the pleasure of tasting some of Paul’s cheese at my local cheese shop Good Taste Food to say they are delicious is an understatement. I asked Paul to let us into his world and below is a fantastic insight into the world of cheesemaking. 

Invited to write a guest blog about cheesemaking, I find myself struggling to find where to start.  How do I begin to explain the intricacies of acidifying and ripening cultures, the fluctuations of milk composition and the huge implications of something so seemingly insignificant as a plus-or-minus one degree celcius variation while heating the curds?  How can I condense the entire spectrum of recipes and techniques, evolved during more than 2000-years of cheesemaking, into 1000 words or less?

Perhaps I should start with the basics – I take 2100 litres of good quality milk and add starter, which is a mixture of lactic acid bacteria (LABs).  This may be a commercially prepared freeze-dried or liquid starter or it may be the whey from the previous days make.  There are pros and cons to any method – and greater risks involved with some over others.  The only important thing is that I add a starter of some description to produce an acidification, because without this I do not control the growth of harmful bacteria.  Acidification works in two ways – the bacteria convert lactose to lactic acid, dropping the pH and making the cheese less favourable to bacterial growth.  Furthermore, the proliferation of a healthy population of LABs provides competition for food and water that may prevent a few invading Listeria monocytogenes or Staphylococcus aureus cells from multiplying to dangerous levels.

Then I add rennet and go home for breakfast – surely one of the most important parts of the cheesemakers day.  As I enjoy a bacon roll and a mug of tea, half a mile away, about half a litre of rennet is snipping casein, a milk protein, into it’s hydrophobic and hydrophillic parts.  The hydrophobic parts avoid water and instead bind to one another to create a jelly-like network of linked proteins.  Milk composition is around 88% water and the hydrophillic bit of the casein binds with this and becomes trapped between the protein network of the gel.  When the curd is cut, the surface area of the curd is increased, encouraging the expulsion of water – in the form of whey.  I can cut the curd finely or roughly, and stir it more or less to remove more or less whey.  For hard cheeses I can heat the curds to help to drive off moisture.  The characteristics of the different cheese types can be attributed to the rate at which moisture is removed and the acidity at that point.  When the curd is ‘right’ for the particular cheese I want to make, I drain start to drain off they whey.

In the case of the Lyburn cheeses, I want to maintain a supple, elastic texture, so I will drain before any significant evolution of acidity.  I also perform what is called a ‘curd-wash’, draining off a portion of whey and replacing it with hot water to wash lactose out of the curd particles and limit the extent to which the acidification can proceed.  If I wanted a more crumbly texture, I would allow more acidification before draining – leaching out some of the calcium responsible for curd elasticity.

It can be a surprise to anyone unfamiliar with cheesemaking to see how little curd you are left with after draining.  Solids in cows milk account for under 10% and, allowing for a little residual moisture, my 2100L of milk should yield somewhere in the region of 210kg of curd which is packed into moulds and placed on the presses overnight.  In the morning, the formed cheeses are turned out into the brine tank, where they float for 24 hours adsorbing salt.  Upon removal and a day or two drying off, the cheeses that will become Old Winchesters are painted with plasticoat and transferred to a fairly dry store; those that will become Stoney Cross are moved immediately to a high humidity store where the rinds will become innoculated with a mix of natural moulds and bacteria that, as an expression of the microflora of the maturing room, is perhaps the truest expression of the ‘terroir’ of the farm.  Moulds of the genus Mucor dominate the rinds of the Stoney Cross. 

This is a mould often seen on the rind of a British Caerphilly or Gloucester- or on Tomme de Savoie in France, where is sometimes has the nickname Poil de Chat (Cat’s fur).  It starts out as tiny fuzzy white patches on the rind after about two weeks, developing a silver-grey pigmentation as it continues to develop.  After about one month, the mould growth is thick and even and the weekly-brushing of the rinds can be compared to grooming a Russian-Blue cat!  As the cheese matures, the rind becomes thinner and browner in colour.  It imparts a lovely earthy note to the three month-old cheese, acting as a counterpoint to the sweet, buttery flavours of the paste.

The manufacturing process of a cheese occupies only a very tiny portion of the timeline but it covers the period which bears the greatest influence on the end product.  Affinage can take a well-made cheese to a higher level but it can never correct a defficiency in the production process.  This becomes critically important when making Old Winchester.  Any variability in the production may influence the final flavour and it could take a long time to spot any problems emerging during the eighteen-month maturation or to find better ways of coaxing out the rich, complex flavours.

Five days in every seven, I make cheese.  Every year, I tell myself that I’m finally getting somewhere in understanding my cheese.  Twelve months later I realise how little I actually knew the previous year!  Add to that the seemingly impossible task of estimating demand for a product, nearly two years before it is sold and it starts to become clear that cheesemaking is not the easiest way to make money.  British cheesemaking is however in a much stronger position today that any point arguably in the past century and new cheesemakers are joining the industry every day.  Are you hard-working with a keen interest in lifting cleaning, plumbing and microbiology? British Cheese needs YOU!

To find out more about Paul then you can follow him on Twitter or check out the Lyburn Farm website here.



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