I was speaking at the Leamington food festival, to an audience that was frankly more interested in the free steak samples than hearing about beef production, when I was rather rudely interrupted by a friend and fellow butcher. He strolled onto the stage, picked up a mic and announced:

“You don’t dry-age beef, you hang beef! They don’t know what you mean, it’s just a fancy term for something we’ve been doing for years” He did have a point. Hanging sides of beef is a traditional process that dates back to the 19th century, to tenderise the meat using the natural enzymes present and intensify flavour as moisture is lost.

Tradition and Technology

What we were working on at the time was using technology to discover the optimum hanging conditions, testing the results to deliver consistently excellent beef, without relying on just the eye of the artisan. Up to that point, our methods mirrored what most good butchers do and had remained largely unchanged since the 1980’s, in the UK at least.

If you start with well-husbanded grass-fed beef with good fat cover, place steak cuts on the bone in fridges and leave them for 21 to 28 days, you will get a good product, sometimes a great product. When you compare this to supermarket steaks and those in most restaurants, the difference is a great as between cooking wine and a fine claret.

Why mass-market steaks are so disappointing

Most mass-market beef is of poor quality to start with and often is just 12 months old, which means that the meat will be bland. Post-slaughter, the beef is boned out whilst hot and put into plastic bags to “wet age” it, whatever that means? It’s not a process that is known for creating tender, flavourful meat.
This is the most common practice worldwide today for one reason: cost. Holding product for a long time in refrigerated conditions is expensive. Added to that, dry-aging beef yields less meat than “wet-aging”, because on average 12-15% of its weight is lost due to moisture evaporation. This yield loss is absorbed by the producer. This is anathema to the supermarkets and large food groups , whose main aim is profit and so yet again they find a way of speeding up the process at the expense of flavour.

Although we had an excellent product and a loyal customer base, including some of the country’s top chefs, I wanted to understand why sometimes our steak tasted markedly better than usual.
Steaks that were sublimely delicious, a next level of tender beefy goodness that I wanted to make our standard.

Applying the science

To achieve this, we needed to understand what the variables were and apply a more scientific approach, to ensure that excellence was our standard.
As Heston Blumenthal says about gastronomy, “question everything!" We started our research and although I found some data from the USA, where dry-ageing of beef is part of food culture, there was by no means a handbook available. As a result, we started by exploring the 4 main factors: temperature, humidity, air flow and time.

The easiest variable to control is temperature -but what is the best temperature? What happens if you increase by 1 degree or decrease by 2?
There was also the impact of putting meat into the fridges. If it’s warmer than the other beef already in there it will raise the overall temperature of the room. When you open the door, you introduce warmer or cooler air from outside, depending on the season.

Our first step was to put all of the beef for that maturation cycle into the same fridge at the same time and quite simply, to keep the door shut for the duration. We could then ascertain the perfect temperature by examining the beef and carrying out taste tests.

The second variable is humidity. During a research trip to Parma to look at ham production, I saw that while traditionally mountain air is used to mature the hams, producers are now additionally replicating the process with technology to achieve a humidity level of 75% in their fridges. If you hang the hams in a fridge with too high a moisture level you create mould, but if it’s too low the hams will dry out. The same is true of beef.

Many of my butcher friends use Himalayan salt to age their meat, some with good results and we did explore this option briefly. As well as being a lovely story, it does take moisture out of the air which will inevitably improve the product. However, we found this method had too many variables to ensure consistency. We couldn’t work out how much salt you needed per kilo of meat or even how to check when the salt bricks had become saturated and couldn’t absorb any more water. We also looked at dehumidifiers but soon settled on using the natural drying process of the fridges to lower the humidity and then introduce moisture when the levels dropped too far. Naturally, the optimum humidity level we settled on through our research is now one of our trade secrets.

Air flow is also vital. Most maturation rooms have fans at the front of the fridge that blow out cold air and cool the room. This means that the cuts of beef at the front are impacted more by the drying process more than those at the back. We introduced other fans and then tested the air flow using monitors, to ensure equal air distribution so each piece of meat was dried or matured equally.

The final variable was the time we left the beef to mature. It is well known that the most dramatic increase in eating quality occurs in the first 14 days of dry ageing. Opinions, however, vary on what is the ideal time is. Although you do see 50 day aged steaks and even longer on some menus, 21 days has been an industry norm for some time. For us 35 days is optimum. This is of course reliant on the other variables being correct. At this maturation level you get great tenderness married to a lovely beefy flavour, without the product being overwhelmed with gamey or musty flavour notes that can infect longer matured meat, particularly if the moisture level is too high.

The Artisan’s Eye

We were then able to use a shear tester to check for tenderness. This odd piece of kit replicates the human bite and gives a reading on the amount of force it takes to push or bite through the meat. The penultimate check is the artisan’s eye. The accumulation of years of experience that means that when you look, feel and smell a product you just know when it’s perfect.
Only then do we carry out the last test, the tasting. Everything that we do is geared up to that moment the steak arrives on the plate and we cut into that beautiful piece of meat. Tender, salty and caramelised on the outside with just a hint of pepper, but still pink in the middle.

The first taste of that deep beefy flavour and juiciness, with an after taste that keeps you going back for another bite - and we know we’ve got it right.
Quality takes time and great food should never be rushed. The whole process is more complicated than it used to be, but the result has been to achieve what we set out to do, producing excellence as standard.