Dry ageing of beef

Words: Richard Turner   Illustration by Samuel Esquire

Dry ageing of beef

Leave it to the experts


I’ll lay my cards on the table: I’m no fan of overly aged beef.

In the wrong hands, and that’s most hands, ageing of beef for anything over one month produces flavours that mask the true nature of the beef. The meat picks up distinctly funky fermented flavours, and if this process masks the flavour of good beef, then similarly, it can be used to mask the flavour of inferior beef (in the wrong hands).

To compound the issue, in the ‘60s, a new process of wet ageing in vacuum pack appeared, causing meat hanging to almost stop entirely. Wet aged beef undergoes considerably less moisture loss, making it up to 20% cheaper than dry aged. In this process, the meat is butchered, then vacuum sealed and left in the fridge to “age”, when in fact, it cannot change much since there’s no contact with air and no moisture can escape. Neither does it benefit from the weight of the quarter pulling on muscle fibres. This process gives scope to advertise “aged beef” without technically lying, and all the while keeping the weight of the product up and the margins high.

True ageing of beef is the process by which meat is hung after slaughter, to allow some moisture to escape and to tenderise it. In the UK, this is called ‘hanging’ and in the US ‘dry aging’. If beef is eaten too fresh, it’s wet, can lack flavour and can be tough, but dry-hanging for a couple of weeks improves these elements. Hanging beef has been practiced for hundreds of years, since butchers discovered this, and after falling from favour in the ‘60s, it experienced a surge of popularity in the ‘90s, continuing to be popular amongst connoisseurs of good beef. One reason for its return to favour is that, due to the BSE crisis of the nineties, we are now killing younger cattle, and the meat of younger animals needs a helping hand (not an issue with older cattle).

The process of hanging beef involves a controlled environment at between 1-4 ° Celsius; any warmer and the meat may spoil, any cooler and the water in the meat might freeze, causing the ageing to stall. Beef is hung on the quarter, the largest manageable size possible, so that the weight of the quarter assists in the tenderising. Due to the need for the water to evaporate slowly, the room must be kept to a humidity of around 80% and to prevent bacteria developing on the meat, the room is kept well ventilated, often with fans. The whole process needs careful monitoring at regular intervals to ensure that it is working correctly.

As the water leaves the meat it concentrates the taste, making for a rich and savoury flavour. The meat is also starting to break down at this point; there are several theories (enzymatic or non-enzymatic) explaining this process, but the ‘Calpain’ theory of tenderisation is recognised as the most probable. The job of these Calpains in living muscle is to break down proteins to be synthesized into newer proteins, and this process continues after slaughter, but without the newer proteins being synthesised. The meat becomes tastier as those proteins are broken down into amino acids, including glutamic acid, or umami. And so you get tender and tasty beef! The appearance of the beef also changes through this dry ageing process, the meat changing colour from red to purple and becoming much firmer than fresh meat.

This whole procedure takes at least two weeks. At this point, the meat will be noticeably tastier but this length of time also results in a greater chance that the meat will spoil. Furthermore, dry aged meat shrinks, as much of the water has evaporated and this loss of mass causes the meat to decrease 10-15% in weight. So, due to expense, meat hanging is less popular in intensive meat production. Since the process requires a large room with specific environmental needs as well as constant attention, the price per kilo of hung meat is substantial.

There are however a few expert butchers who are going much, much further: extreme ageing for as much as a year, occasionally even longer! Jose Gordon of El Capricho in Spain ages up to 200 days, Renzo Garibaldi in Peru ages up to 300 days, and Peter Hannan in Northern Ireland has been known to age more than 400 days! It’s important to point out though, that these guys are experts in this field, and are very much the right pairs of hands.