Aroma is not created by time alone: How microorganisms contribute to ageing

Ageing flavour is often described through method and number of days. A 2023 study in Foods shows why that explanation is incomplete. Researchers compared beef rump under different post-mortem ageing processes and linked measurable volatile compounds with the dominant bacterial and fungal communities.

Original study figure

Flavour is a network, not merely the result of elapsed days.

The study recorded product quality, volatile compounds and microbiota during wet and dry ageing. Eleven of 65 detected compounds were classified as aroma-active based on their odour activity. Several aldehydes and alcohols, including hexanal, nonanal and 1-octen-3-ol, were particularly enriched in samples wet-aged for seven days. Depending on concentration, these compounds can contribute fatty, grassy, mushroom-like, citrus or fruity notes.

Microbial communities also differed substantially according to ageing method and time. A correlation model identified five genera closely associated with several key aroma compounds. This does not prove that every detected microorganism directly creates a particular flavour. It does show that flavour development is biologically interconnected and cannot be explained by moisture loss or enzyme activity alone.

Within their experimental design, the authors found wet ageing for up to seven days favourable in terms of yield and colour stability compared with dry ageing. This must not be read as a universal judgement on every ageing system: the work examined specific samples, short periods and defined conditions. That limitation is precisely what makes its interpretation valuable.

For businesses, the implication is clear: ageing is a controlled ecosystem. Raw material, hygiene, temperature, packaging, humidity, time and subsequent cooking jointly shape the sensory result. A label stating “21 days” or “dry aged” names a process parameter, but not yet a reliable flavour profile.