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Bronwen Percival is one of the UK’s leading cheese experts. She is Neal’s Yard Dairy‘s buyer and technical manager. She also co-authored, with her husband Francis, the book “Reinventing The Wheel – Milk, Microbes and The Fight For Real Cheese”. 

Would you please give us a potted biography?

I come from a dairying family: my mother’s grandfather was a Swiss dairy farmer who emigrated to the United States at the turn of the 20^th century, and she grew up on the family’s dairy farm in southern California. My own ambitions as a child were geared toward science, but after studying biochemistry at university, I spent two years as a volunteer with the Peace Corps in Senegal. Returning to the US, I turned towards working with food, and spent a year working at a winery and a small cheesemaking dairy before coming to the UK to do a Master’s Degree in Anthropology, where my dissertation focused on Protected Geographical Indications (protected food names) and their complex relationship with concepts of tradition. As part of my research, I visited Neal’s Yard Dairy in London, and took a job there as a cheesemonger on completion of the course. A year later I became the buyer, and now I manage the buying, technical, and new cheese development side of the business.

We take it for granted that people know how cheese is made but it’s useful to have a straightforward definition! Would you quickly describe the process from cow/goat to final cheese?

Making cheese is a way of preserving fragile, perishable liquid milk in a form that is much lighter and longer-lived. This transformation entails two different processes: the removal of extra moisture from the milk to concentrate the milk solids (‘drainage’) and fermentation, which in this case is a bacterial process during which milk sugar (lactose) is metabolised into sour lactic acid. The way in which the drainage and the fermentation are coordinated (does one come first, or do they happen simultaneously?), and the amount of moisture that’s removed, gives rise to the many styles of cheese, from the soft and oozy to the hard and crystalline.

Cheeses made from unique and interesting milk from extensive, low-input farming systems are sold alongside others made from commodity milk as if they are exactly the same.

You may have heard of rennet, the enzyme that is used to turn liquid milk into a jelly-like permeable curd from which moisture can be removed through cutting, stirring, and heating. The most common form of this enzyme is an extract from the stomach of a baby ruminant (calf, lamb, or kid), though plant enzymes from cardoons or thistles can also be used to set the milk. Today, most factory cheeses are made using enzymes synthesised in the laboratory, though we encourage farmhouse cheese producers to use the more expensive natural enzymes.

You wrote a book with your husband Francis called Reinventing The Wheel: Milk, Microbes and The Fight For Real Cheese. What prompted you to write the book and can you explain what you mean by “real cheese.”

Writing RTW was a labour of love. Part of the impetus for writing the book was meeting and collaborating with French and American microbiologists who are studying the microbiomes of milk and cheese, who are making the case that if we are to make unique and interesting cheeses that tell us something about where they come from, we need to rethink milk production. It’s a fantastic story because it inverts the standard line about white-coated scientists ruining a traditional food; here, it is the scientists with the cutting-edge research labs who are realising how much we have lost on the path toward cheapness, consistency, and efficiency, and pushing the cheesemakers they work with to work in a different, more holistic and sophisticated way.

It is the scientists with the cutting-edge research labs who are realising how much we have lost on the path toward cheapness, consistency, and efficiency.

Meanwhile, in my work at Neal’s Yard Dairy, I began to recognise the extent to which production practices with integrity are not rewarded by the current conversation within the industry. Within the cheese industry at large, cheeses made from unique and interesting milk from extensive, low-input farming systems are sold alongside others made from commodity milk as if they are exactly the same, and gimmicky starter cultures (the equivalent of cultured yeasts designed to give particular flavours) are used to add flavours that are overtly appealing yet totally without intrinsic personality or character. We’ve coined the term ‘real cheese’ to describe those that have something unique and interesting to say, and that allow us to taste a complex and laudable farming system in its entirety. If we don’t do something to help cheese-lovers recognise and appreciate the meaning of these rare, endangered flavours, we may lose them altogether—and that would be a tragedy.

How far back can we date cheesemaking?

Cheesemaking has been practised for thousands of years, and it’s a testament to human ingenuity (and the power of trial and error) that people managed not only to evolve cheesemaking methods suitable to their environments and farming systems, but also perfect them, long before anyone knew about microbes and their role in the process!

What were cheeses likely to have been like then? (do we know?)

To be honest, we have no idea. But a really exciting part of the work that is being done by cheesemakers now is to go back to old books and sources and try to imagine—and even attempt to recreate—those processes. Of course, as I alluded to above, recreating a cheese as it would have been made 150 or 200 years ago requires more than a recipe; it is a process that starts with rethinking farming practices. What would the stocking rates (number of animals per acre that a farm could support) have looked like then? What sort of animals would they have been farming, and what sort of yields would they expect? How would the milking be done, and how—in a world without commercial starter cultures—would the fermentation be encouraged? The cheesemaking process itself has changed much less over the years than the things that have changed invisibly in the background.

If we don’t do something to help cheese-lovers recognise and appreciate the meaning of these rare, endangered flavours, we may lose them altogether—and that would be a tragedy.

What’s clear from the old books on the subject is that British cheese has changed dramatically, even in the past hundred years. With the popularisation of starter cultures (and the delegation of cheesemaking to paid employees rather than woven into the fabric of the day’s activities), the process has got much faster, with the result that many British cheeses taste far more acidic, and are far more crumbly and short-textured than they would have been even a few generations ago. In a book from the early 1930s, a Cheddar instructor talks of how a ‘sharp acidy flavour’ will result in a cheese being downgraded from first- to second-quality. But today, when almost all cheese is made fast, we have redefined Cheddar as a ‘sharp, acidy’ cheese. We’ve completely lost our collective memory of the ‘rich, mellow’ Cheddars that defined the style a century ago.

When did more commercial cheesemaking come in, and in what ways did an artisan process become homogenised?

The first cheese factories appeared in the north-eastern United States in the mid-nineteenth century, and it wasn’t long before cheap factory cheese began to displace the more expensive farmhouse version—most people bought on price, even as they accepted that the quality of the mass-produced article was not as good.

It only takes a couple of generations for irreplaceable knowledge and skills to be lost.

Developments such as starter cultures and pasteurisation (heat-treatment to kill pathogens and many of the native microbes in the milk that participate in the cheesemaking process) resulted in more uniformity and consistency, and probably raised the standard of a lot of so-called ‘tainted’ cheeses made from poor-quality milk. Today, it’s possible to get very respectable mass-produced cheese; block Cheddar from a factory is made using more-or-less the same process as a farmhouse Cheddar, and sells for a cheaper price. But any connection between the flavour and the farm is lost, just as mass-produced factory wines workshopped to appeal to a mass audience don’t tell us anything about the character of a specific site.

Why did this happen?

At the outset of the project, we half-expected to find ‘The Big Bad’: the one person or company (ideally long-dead or out of business to avoid us getting sued!) at fault for the catastrophic decline of real cheese. Instead—and in retrospect, unsurprisingly—the culprit was the changing selective ecologies in which those cheeses found themselves over time. When farmers suddenly find, as they did in 1933 when the Milk Marketing Board was formed in the UK, that they can make a better living selling liquid milk than making cheese on the farm, they react rationally and stop making cheese. Likewise, when consumers decide that price is more important than flavour, producers intensify their systems to make their products less expensive, even if that has unfortunate consequences for the flavour. It only takes a couple of generations for irreplaceable knowledge and skills to be lost.

Did people write down recipes for cheesemaking? Are people recreating cheeses by trial and error or are there written records/archives?

For a straightforward process, cheesemaking is maddeningly difficult to write down in an accurate way. There are a lot of variables involved (temperature, the progress of the acidification, the speed at which the curd is contracting and losing its moisture) for the cheesemaker to react to, and a change in one of these will have knock-on effects on the others. Perhaps the biggest challenge is the process’s reliance on sensory information: the feel, taste, appearance, or even smell of the curd as it acidifies. This is the information has been lost as farmhouse cheesemaking became less and less practiced, and the practices of the few producers that remained drifted—in some cases beyond recognition—over the intervening decades. The cheesemakers who are experimenting their way back towards those old cheeses are relying on clues gained from the sometimes-maddeningly incomplete information in old books, coupled with information from contemporary dairy technologists (often from places with better technical infrastructures supporting farmhouse cheesemaking, such as France) and tactile feedback and experience: is the curd behaving itself? Is it cooperating? Does it look and smell good? And finally, when it is ripe, how does it taste?

Can cheese exhibit “terroir”? If so, can you give some examples of ways that it manifests itself?

As we say in the book, cheese, even more than wine, is an agricultural product that allows the consumer to taste the decisions made by the farmer-producer. This works on many different levels: the ‘macro’ (the biodiversity of the plants growing on the farm that the animals are eating), ‘meso’ (the breed of animal used to transform these building blocks into milk with characteristic properties), and finally the ‘micro’ (the native microbes that inhabit the raw milk, whose identities are linked the farming inputs and the way the milk is handled). Taken together, the ultimate quality potential of the cheese is set by the quality of this milk—the cheesemaker can then just do their best not to mess it up! Unfortunately, even if the milk produced is excellent (and there’s plenty of faceless milk out there) it’s still all too easy for the cheesemaker to erase or cover up the inherent character of the milk. It can be pasteurised, which levels the playing field between boring and interesting milk by killing many of the native microbes that might otherwise participate in the cheesemaking process. But even raw-milk cheeses can use strongly flavoured starter cultures which impart their own designer flavours to the cheese. There’s nothing inherently wrong with those flavours—many of them are designed to be overtly delicious—but using them is a moral hazard: it means that the quality of the farming, and the character of the milk itself, doesn’t matter. And those same flavours can be produced in a large factory down the road at a fraction of the price, just as easily. If it doesn’t bear a clear stamp of place, making farmhouse cheese is a waste of energy and time: customers should save their money and eat factory cheese instead.

Do we overvalue consistency in cheese? Or should there be a consumer-friendly standard or should we educate consumers to assess cheese on look, smell and taste?

Of course, consistency of quality is important: cheesemaking requires control, and a loss of control that results in faulty cheese is as much of a problem as a cheese whose character is smothered by added flavourings. In both cases, we aren’t tasting the potential of the farm, but rather a form of convergence, whether it is ammonia gas or bruised paste or sandy blue veining. Some people enjoy those things that others would consider faults, and of course it’s up to the individual what they choose to spend their money on; it is not my job to be prescriptive. But helping people to recognise what they are seeing, smelling, and tasting when they pick up a piece of cheese is something the industry needs to do better. It’s not difficult to learn the signs: how we can tell if animals have been eating grass or fed concentrates, the tell-tale tastes of adjunct cultures, or simply the aroma and sensation of cheese that’s been suffocated as it matures. We need to share this information with people, not to dictate what they choose to buy, but so that they can make an educated decision for themselves.

Describe some of the experiments that are currently being conducted at Neal’s Yard Dairy.

It’s an exciting time right now. There’s a lot of experimentation going on at farms and new cheeses in the pipeline. Working with producers who are developing new cheeses is not new for us, but some of these new cheeses are particularly exciting as they’re an evolutionary step forward towards what we can expect to see more of in the future: people making British territorial cheeses without added starter cultures, using only the microbes from their farm and milk, and cheeses made from the milk of rare-breed animals with minimal inputs from outside the farm. If we want to understand what cheeses might have tasted like a century or two ago, we have to think beyond recipes and start looking at systems. There is tremendous potential.

What is unpasteurised cheese? When tasting an unpasteurised cheese against a pasteurised cheese, what would we be looking for?

I prefer the term ‘raw-milk cheese’ to ‘unpasteurised cheese,’ as the latter can hide a multitude of sins! Pasteurisation is a process that involves heating milk to a certain temperature (72C for 15 seconds), which has been shown to kill the most heat-tolerant pathogen (bacterium that could make us ill) associated with milk. Some producers might sell ‘unpasteurised’ cheese that has undergone a heat treatment less than pasteurisation, designed to kill the more heat-sensitive pathogens but also sacrificing many of the interesting and beneficial bacteria as collateral damage. Raw-milk cheese uses milk that has not been heated above the temperature of the cow before the cheesemaking process starts. It retains all the microbial potential of the original milk—it also means that the milk production practices must be absolutely fastidious.

If we want to understand what cheeses might have tasted like a century or two ago, we have to think beyond recipes and start looking at systems. There is tremendous potential.

Assuming the cheese is made with interesting milk—milk with a healthy and diverse microbial population—and that the make has been optimised to express that, raw-milk cheeses have a longer and more-complex flavour than pasteurised-milk cheeses. It’s not surprising, really: flavour in cheese comes from the breakdown of the milk proteins and fats by enzymes produced by microbes during the making and ripening process, and the greater the microbial diversity, the more different types of enzymes will be present, and the more aromatically complex the finished cheese will be when it’s ripe.

We are used to using descriptors and metaphors for wine tasting notes. When you are tasting cheeses, what are some of the common descriptors?

I’m familiar with the UC Davis wine aroma wheel, with its numerous aromatic descriptors, and I must say that I believe the ‘fruit salad’ approach to describing the character of a wine or cheese is pretty useless. I’ve seen some data where even trained wine professionals had an abysmal success rate matching such notes with the wines that they described in a blind tasting, so the evidence is against them as well.

When I taste cheese critically, the aromatics (does it smell of coffee or of burnt butter?) are the least important thing; they are an afterthought. Instead, the important things are the structure of the paste, the texture, the acidity, and absence of things like bitterness or soapy or metallic flavours. If these elements are in place, and the milk is characterful, chances are excellent that that cheese is going to have something interesting and worthwhile to say when it’s fully mature.

I do think metaphors, particularly shape metaphors, can be very useful: describing the flavour of a cheese as ‘round’ as opposed to ‘angular’ immediately tells you a lot about its character, even if you aren’t someone who has vast tasting experience. It’s a very interesting area for exploration, particularly in how we can guide customers quickly to the style of cheese they’re looking for, even if they aren’t quite sure how to express it themselves. 

What are the main difficulties with being a small cheese producer?

It’s not an easy life. Small farmhouse producers (who own the animals and make the cheeses themselves) have milk demanding to be processed non-stop, and if they’re committed to making the best quality of cheese, they must do it every day. You can’t put fresh raw milk in a refrigerated bulk tank and come back twenty-four hours later and expect it to be the same raw material you started out with: different microbes become active at cold temperature, and they’re never the ones that make cheeses better. So there’s a non-stop requirement to be making cheese: one of the reasons why milking animals seasonally makes so much sense; it’s not just the animals that need a break in the wintertime!

We underpay for the very best cheeses today—and we need to pay more if they’re to continue more than a generation.

There’s also the problem of price: we’re all benchmarked against supermarket prices now, and while artisan cheeses have the reputation for being expensive, their price is only a minute fraction of what they would have been—adjusted for inflation—a century and a half ago. With intensive agriculture, food in general has got much, much cheaper. But working within those same sorts of systems today is just as expensive as it would have been long ago: there is nowhere near the same economy of scale, the raw materials are produced less-efficiently, and the labour cost per unit is off-the-scale by comparison. Yet we expect two-to-three times the price of the industrial product to be sufficient to make ends meet. We underpay for the very best cheeses today—and we need to pay more if they’re to continue more than a generation, or we want more diversity of cheeses made this way to be available.

You mentioned it is nigh impossible to make certain types of French cheeses in the UK. Which ones is it almost impossible to replicate and why?

Ahh, we’re back talking about terroir again! The truth is that each style or family of cheese evolved as a rational solution to a set of social, climatic, and environmental contingencies. British cheeses are a perfect example: our wet climate makes it very likely that British milk will contain spores of a bacterium that causes what’s known as the ‘late-blowing defect’. When this occurs, cheeses inflate with gas produced during the maturation process, leaving gaping fissures in the paste and the flavour of vomit. But even if these spores are present, their growth can be controlled by curd that is higher in acidity and salt. Classic British styles of cheese—the Cheddars, Cheshires, Lancashires, and even Stiltons—evolved to have higher acidities than their Continental counterparts. The practice of mixing salt into the curds rather than brining or surface-salting contributes still further to controlling these spores. (Today, it’s also possible to cheat by adding antimicrobial agents like the enzyme lysozyme or nitrates, but that seems a disappointing patch.) With extremely careful farming and seasonal production, it might be possible to make an acceptable alpine-style cheese in the UK without chemical additives, but the deck would be stacked against the producer. But life is a lot easier (and the end results are often far better) when we work with—rather than against—our raw materials.

Any inspiring stories of small producers who have taken risks or changed the way they have done things?

The world of farmhouse cheese is full of inspiring people—nobody gets into this business because it’s an easy life, or for the cash rewards. The odds are against farmhouse cheesemakers in the English-speaking world: there is very little support or technical infrastructure available, and there’s a high bar for the knowledge required to make a cheese that’s adequate, let alone extraordinary. Everyone who makes a great cheese in this country has done it through sheer force of will. The frustrating things for me are that (a) it’s so difficult for people to succeed (b) there’s so little financial reward for those who do. Under these circumstances, we’ll most likely continue to find a few superhuman cheesemakers who are in it for the love of the craft, but it’s fairly unlikely that their children will be tempted to continue down the same path. We don’t yet have anything close to a system or a market that will promote the redevelopment of a thriving, vibrant, and secure ecosystem of farmhouse cheesemaking.

Do you give ever yourself a break from eating cheese?

Never! 🙂

Did you have a cheese epiphany, an experience that made you change the way you perceived cheese taste and cheesemaking practice?

There was no single momentous epiphany, but my taste in cheese now is completely different than when I started out as a cheesemonger years ago. I remember working in the shop and not being able to understand why the favourite cheese of the person who was training me was Kirkham’s Lancashire: I thought it was boring, and too much like what I thought of as supermarket cheese. I liked powerful blue cheeses and oozy, creamy soft cheeses, not something white, crumbly, and just a few months old. The subtle, warm, milky length of flavour of the Kirkham’s was completely lost on me. Now it is amongst my favourite cheeses as well, and I spend a lot of time thinking about how we can encourage consumers to go on the same sort of aesthetic journey that cheesemongers tend to over time as they taste thousands of cheeses. Sweet goudas and creamy camemberts are all very nice, but even the raw-milk ones are seldom profound. How can we gently coax people out of the safe and comfortable realm of the familiar, and encourage them to open their minds to subtle and complex flavours they may not have even been aware of before?

How do you see the medium/long term future for UK artisan cheesemakers in terms of Brexit and government subsidies to small farmers?

It’s going to be tricky to say the least. A huge amount of the best British farmhouse cheeses are sold into Europe, where there are millions of people who eat and appreciate—and most importantly, are willing to pay for—excellent cheese. If barriers to trade are put up, the market here is not necessarily going to pick up the slack. I’ve been working to set up lines of export of raw-milk cheeses to other countries around the world, where we even have customers who are eager to buy them from us, but the bureaucratic inertia and regulatory red tape is unbelievable. Trading further afield to replace what we might lose in Europe is no panacea.

However, the message from the government about paying farmers for public good—in the form of environmental stewardship, biodiverse and extensive farming systems, and the like—could be a small silver lining. These careful and responsible farming systems produce potentially the most interesting milk for unique raw-milk cheeses. If there’s a helping hand for more people to adopt that sort of approach to farming, that must be a step in the right direction for great farmhouse cheeses (not to mention our planet).

What are the parallels between artisan cheesemakers and small natural wine producers? And between unpasteurised cheese and natural wine?

There are so many—in fact, reading the above, it’s clear that there are no new ideas in Reinventing the Wheel: they have been lifted wholesale from the wine industry, where there is a similar range of styles from the big industrial (cheap and consistent) behemoths all the way through the elite single-vineyard bottlings from tiny domaines that carry the stamp of a unique and special place.

In many ways our philosophy of cheese is very similar to that of the greatest natural wines: farm carefully and with intention, promoting biodiversity (of plants, animals, microbes), and then process sensitively, shepherding the raw materials through a process that makes them taste more clearly and distinctively of themselves. Don’t lose control of that process through inattention or care: that way lies VA problems (in the case of wine) and terrifying feral cheese. But using knowledge and a gentle hand to push great raw materials in the right direction is the way to make the very best of anything, not just wine or cheese.

In many ways our philosophy of cheese is very similar to that of the greatest natural wines.

Those who are interested more in these parallels might be interested in winemaker Diana Snowden Seysses’ keynote address at the Science of Artisan Cheese Conference back in 2014, available to watch HERE.