Us humans have very strong stomach acid. At a Ph of 1-2, it can be stronger than the acid in a classic lead-based car battery.
Why dry age meat?
Early humans might first have started cooking their food to make carrion safer for them to eat, new research has suggested. Anthropologists at Harvard University have found that humans scavenging for meat from carrion would have risked exposure to dangerously high levels of bacteria.
Are humans omnivores or facultative scavengers?
Source – The significance of cooking for early hominin scavenging – The Journal of Human Evolution.
Meat scavenged by early Homo could have contributed importantly to a higher–quality diet. However, it has been suggested that because carrion would normally have been contaminated by bacteria it would have been dangerous and therefore eaten rarely prior to the advent of cooking. In this study, we quantified bacterial loads on two tissues apparently eaten by hominins, meat and bone marrow. We tested the following three hypotheses: (1) the bacterial loads on exposed surfaces of raw meat increase within 24 h to potentially dangerous levels, (2) simple roasting of meat on hot coals kills most bacteria, and (3) fewer bacteria grow on marrow than on meat, making marrow a relatively safe food. Our results supported all three hypotheses. Our experimental data imply that early hominins would have found it difficult to scavenge safely without focusing on marrow, employing strategies of carrion selection to minimize pathogen load, or cooking.
As we can see from the above study, early humans would have had more access to carrion, meaning dead and decaying animals that had been killed by other animals. Cooking this meat would not just have made it safer, but would also have increased the bioavailability of the nutrients in the meat.
The chart above shows stomach acid strength in the animal kingdom. We've highlighted the other animals that share our measurement of Ph 1.5. We're in unusual company with the black-headed gull and possums (both facultative scavengers), the ferret (a generalist carnivore) and the wandering albatross (an obligate scavenger). Facultative, by the way, means 'occurring optionally in response to circumstances rather than by nature', and obligate means 'no other choice'.
It could therefore be concluded that we have evolved biologically to eat rather old meats. After all, the only omnivore on the list with a lower Ph is the common moorhen at 1.4 – the other omnivores are 2.6 and above.
What animals did we eat, way back then?
The majority of meat available to early humans would likely have been very large animals called megafauna, such as the now extinct woolly mammoth. These animals, although very large, are lacking in defence mechanisms such as large teeth or claws, making them easier prey for both humans and other hunting and scavenging animals.
It could be argued that we have evolved to eat the slightly decaying meat from large grazing herbivores that we put on the fire. That sounds like aged steak on the BBQ to us!
How do we know if meat is safe to eat?
Gas leaks, garlic breath, skunks in the neighborhood—ah, the scent of thiols. The human nose is particularly sensitive to these sulfur-containing compounds, which is no surprise given that they are often associated with things to avoid. But how exactly are our nostrils (and those of other mammals) so adept at sniffing out thiols when other odors, such as bleach or vinegar, require higher thresholds of molecules in the air for us to detect them?
The hypersensitivity comes down to the metal copper, according to a team of chemists from the U.S. and China. As they reported this fall in the Journal of the American Chemical Society, the researchers discovered that the same receptors in the nose that pick up these unpleasant-smelling molecules also bind with particles of copper that reside in nasal mucus. The metallic partner amplifies a thiol's intensity by up to 1,000 times. And in experiments in which the scientists created thiol receptors that could not bind with copper, sensitivity to the odorant all but disappeared.
Evolutionarily, it pays to have a nose that can pick up the minutest presence of thiols, says study co-author Eric Block, a chemist at the University at Albany, State University of New York. The sulfur compounds are released by rotting food, for instance, and some predators give off olfactory cues to their presence in this form.
So we can conclude that we know all too well when a food is nicely aged and just downright rotten.
What is dry aging?
In short dry aging is a controlled decomposition and has probably been used one way or another since we started hunting and scavenging.
Dry aging is the practice keeping a selected cut of meat in a controlled atmospheric environment. Generally this means keeping it relatively dry and a few degrees above freezing. This causes chemical and biological changes to occur, the most notable of which is a dehydration as some of the moisture content is lost, which will concentrate the the flavours.
In many ways dry aging beef is no different from making cheese or wines; a semi-controlled process of decay and fermentation brings incredible complexity of flavour.
Naturally present enzymes in the beef’s cells break down protein, fats, and glycogen. With time this causes the meat to become tender, softer, and more palatable.
The process of dry aging usually also promotes growth of certain fungal (mould) species on the external surface of the meat. This does not cause spoilage, but rather forms an external crust on the meat's surface, which is trimmed off when the meat is prepared for cooking. These fungal species complement the natural enzymes in the beef by helping to tenderise and increase the flavour of the meat. The genus Thamnidium, in particular, is known to produce collagenolytic enzymes that greatly contribute to the tenderness and flavour of dry-aged meat.
How long to dry age?
Pat Lafrieda, the legendary NY-based butcher, describes the stages of dry aging.
7 days: Collagen has just begun to break down, but the steak won’t have the flavor or texture qualities that you look for in a dry-aged steak. Steak is not sold as “aged” at this stage. The meat is still fairly bright, but it will darken as it ages and dries.
21 days: The steak loses 10 percent of its weight in the first 3 weeks through evaporation. The water seeps out the front and the back of the meat, but the fat and bone on the sides of the steak make the sides waterproof. Because meat shrinks, the steak will become more concave as it ages. Although the fat doesn’t shrink, it does darken in the aging process.
30 days: This is the most commonly requested age in steaks. The steak has developed the flavor and texture qualities associated with dry-aged meat: it is very tender, with a flavor best described as a mix of buttered popcorn and rare roast beef. At this point, the steak has lost 15 percent of its total weight.
45 days: The steak has a little bit more funk than the one aged 30 days. You’ll start noticing white striations in the meat which is a mixture of mold and salt. The steak has lost only a fraction more weight, and the flavor of the fat changes before the meat does, so it’s important not to trim off all the fat before you cook it.
90 days: The white crust develops even more. This crust protects the meat the same way a rind does with cheese. The exterior crust is shaved off the meat before it is sold.
120 days: Only a handful of very high-end restaurants serve steak that has been aged this long. The steak has lost 35 percent of its original weight. A steak aged this long has a very funky flavor and is also very expensive, so it’s for someone who really appreciates an unusually intense beef flavor.
What cuts do we dry age?
Our sides of beef usually arrive with us having already hung for 21 days at the abattoir. This process of hanging allows some of the actions of aging to begin. For many of the cuts on a carcass, this period of time will increase tenderness and flavour to a sufficient level.
At the point we receive our sides (usually halved into quarters), they are then broken down further into primals. Primals are larger muscle groupings that usually have common characteristics eg the top bit or leg, the chuck and blade or shoulder.
Each butcher will have a specific way in which they like to break and further age their carcass. Our butcher will select which cuts to age and to what extent, depending on certain factors: the function of the muscle group, the methods of cooking typical of those muscles, the texture and colour of the meat, fat coverage, marbling, and even the smell of the meat at the 21-day stage.
Cuts that are chosen for further aging are left on the bone, with their natural fat cap intact. This provides natural protection and moisture through the aging process and aids in the intensification of flavour. Certain cuts are really enhanced by dedicated, longer dry aging, typically roast and steak cuts that benefit from the tenderising and flavour-enhancing actions of the process. Cuts that are slower cooked don't necessarily need to be aged for as long, as much of that is achieved during the cooking process.
The cuts we select for further dry aging include: whole fore ribs of beef (for cote de boeuf, ribeye, rib roasts), bone in loins (for sirloin and t-bone), rump, and for a slightly shorter period the chuck and blade (for chuck, flat irons and Denver steaks). These cuts are carefully monitored throughout the process until they are perfectly aged.
Bespoke aging has become something of a trend among steak connoisseurs who enjoy the nuance, complexity and deep flavours of well-aged steak, sometimes pushed to extremes! We are more than happy to bespoke age pieces for you; if this is of interest please email: firstname.lastname@example.org
Perhaps this is exactly how our ancestors also ate their mammoth meat 35,000 years ago.