Maturing meat — wet aging and dry aging

Freshly slaughtered meat is not automatically tender. After slaughter, the muscles go into rigor mortis, and the meat is tough and somewhat flavorless. It is only when the meat is allowed to age that it becomes tender and develops the deep, full flavor a gourmet butcher is known for. Controlling aging is therefore one of the trade's most important crafts.

§What happens in the meat during aging

When the animal is slaughtered blood circulation stops but the meat's own enzymes continue working. Proteases — especially calpains and cathepsins — slowly begin breaking down the proteins holding muscle fibers tightly together and some of the connective tissue. The result is the meat relaxes and becomes more tender. Meanwhile water evaporates so flavors concentrate and new flavor compounds form giving the characteristic umami-like almost broth-deep taste.

§Wet aging

Wet aging takes place in a vacuum bag in a cool room. The meat lies in its own juice without oxygen, which slows bacterial growth and prevents drying out. It is the most widespread method because there is no shrinkage from trimming, and because it requires less space and management. The meat becomes tender, but does not get the concentrated flavour that dry aging gives, because the water does not evaporate.

§Dry aging

Dry aging (dry aging) takes place without vacuum in a controlled ripening room where temperature, humidity and air circulation are tightly controlled. The temperature is typically close to 0–2 °C and the humidity is kept high enough to avoid complete drying out but low enough to keep mold and bacterial growth in check. The outside forms a hard, dark crust which is cut off before sale. In return, the meat inside becomes intense in flavour and very tender.

§Maturing and food safety

Maturing is not the same as letting meat get old. The whole point is that the temperature is kept just above freezing point so the breaking-down enzymes work while disease-causing bacteria remain dormant. Research from DTU Food Institute has shown that properly aged meat is as safe as fresh meat — provided the cold chain is maintained and the dry outer crust from dry aging is cut off. Document temperature and time so you can stand behind the product.

• 01Keep the ripening room stable close to 0–2 °C — fluctuations prolong and worsen the process.
• 02Measurement units and uncertainty
• 03Dry-aged meat must be trimmed of crust before sale.
• 04Mark each batch with date of entry so maturation time can be traced.

“Maturing is the craft of patience — you cannot force tenderness only control it.”

— Slaughtering principle