Botanical Intelligence: Bay Leaf — From Mediterranean Evergreen to Modern Skincare

Best known as a culinary herb, bay leaf has a much longer history as an aromatic and botanical material. In the first of our Botanical Intelligence series, we look at Laurus nobilis, how its aromatic oil is extracted, what we know about its chemistry and why bay became one of the defining ingredients in Menteath's Smoked Bay Body Ritual.

Bay is probably one of the most familiar plants in the kitchen. Most of us have dropped a dried leaf into a pot without giving much thought to what it is, where it comes from or why something seemingly so ordinary has such a distinctive smell.

The plant itself, Laurus nobilis, is rather more interesting. Native to the Mediterranean, bay is an evergreen tree with a long history of culinary, aromatic and traditional use. Its leaves contain a complex mixture of naturally occurring volatile compounds which are released when the leaf is crushed, giving bay its recognisable green, herbal and slightly woody scent.

It is this combination of plant chemistry, scent and history that makes bay interesting to us at Menteath. We use it in Smoked Bay Body Ritual, where it forms part of a much broader botanical composition, but understanding why it is there means going back to the plant itself.

What is Laurus nobilis?

Laurus nobilis, commonly known as bay, bay laurel or sweet bay, belongs to the Lauraceae family. It is important to make the botanical distinction because several unrelated plants are also referred to as "bay", despite having very different chemical compositions.

The leaves of true bay contain naturally occurring essential oil. The precise chemical profile varies according to where and how the plant has been grown, when it is harvested and the way the aromatic material is extracted. One of its commonly identified constituents is 1,8-cineole, alongside a range of other terpenes and volatile aromatic compounds.

These compounds are responsible for much of what we recognise as the smell of bay, but they have also made the plant the subject of scientific research investigating antioxidant and antimicrobial activity.

Is bay leaf beneficial for the skin?

There is a tendency in beauty to discover an interesting piece of research about a plant and immediately turn it into a sweeping skincare claim. We would rather be more careful.

Research into Laurus nobilis extracts and essential oil has investigated a number of biological properties, including antioxidant and antimicrobial activity. Antioxidants are relevant to skin research because our skin is continually exposed to environmental factors that can contribute to oxidative stress, while botanical compounds with antimicrobial properties are also of interest to cosmetic scientists.

Much of this research is laboratory-based, however, and evidence concerning an isolated plant extract is not the same as clinical evidence for a finished skincare product. Bay shouldn't therefore be thought of as a miracle ingredient or a treatment for a skin condition.

What the research does reveal is just how chemically complex an ingredient we might otherwise dismiss as "fragrance" can be. Aromatic plants produce compounds for their own biological purposes, and we are still learning a great deal about them.

How is bay leaf essential oil extracted?

How a botanical is extracted has a significant influence on what eventually finds its way into a formulation. In the case of bay leaf essential oil, one of the principal methods used is steam distillation.

The leaves are placed into distillation equipment and exposed to steam. As they warm, volatile compounds within the plant material evaporate and travel with the steam as vapour. This is subsequently cooled and condensed back into liquid, allowing the concentrated aromatic oil to separate from the water.

What emerges is not simply a liquid version of a bay leaf. Steam distillation captures a particular part of the plant's chemistry, principally its volatile aromatic compounds. An infused oil or another form of botanical extraction may capture a different range of constituents, which is why the extraction method matters when discussing what a botanical ingredient actually contains.

There is also natural variation from plant to plant. Geography, climate, growing conditions, harvest and distillation can all influence the composition and scent of an essential oil. Working with botanicals means working with materials that began life in a landscape rather than a laboratory, even when the finished formulation is created and assessed with modern cosmetic science.

Scent is chemistry, but it is also experience

One of the reasons we are particularly interested in aromatic botanicals at Menteath is that their role doesn't necessarily stop at the skin.

Smell begins when volatile molecules interact with receptors in the olfactory system. The resulting signals are processed through neural pathways closely connected with brain regions involved in memory and emotion. This helps to explain why a smell can unexpectedly return us to a place or moment we haven't thought about for years.

It could be woodsmoke, damp earth after rain, a particular flower or the perfume worn by someone we once knew. We don't necessarily decide to remember; the association can appear almost immediately.

This relationship between scent and emotion has been central to Menteath from the beginning. Fragrance isn't something we add at the end of formulation simply to make skincare smell pleasant. We are interested in what happens when scent becomes part of the experience of caring for the skin.

Skin, touch and the nervous system

The skin is often discussed by the beauty industry as though it exists independently from the person it belongs to. We talk about cleansing, exfoliating, hydrating and correcting it, but skin is also a highly active sensory organ containing an extensive network of receptors and nerve endings.

There is growing scientific interest in communication between the skin, nervous, immune and endocrine systems, often discussed in relation to the skin-brain axis. Within cosmetic science, this has contributed to the developing field of neurocosmetics and to a broader conversation about how stress, emotion and sensory experience relate to skin health.

This is an area we'll explore in much greater detail elsewhere in the Menteath Journal, because it deserves more than a paragraph and it is also an area where claims need to be made carefully.

What interests us here is something simpler. Applying skincare is a sensory experience. When you massage an aromatic body oil into the skin, you experience texture and temperature through touch while simultaneously encountering its scent through the olfactory system. If that scent has a memory or emotional association for you, that becomes part of the experience too.

It is difficult, therefore, to think of skincare purely in terms of what happens at the surface of the skin.

Why we use bay in Smoked Bay Body Ritual

Bay is one of the botanicals that gives Smoked Bay Body Ritual its particular character. The formulation combines plant oils including olive, jojoba and wheatgerm with an aromatic blend that includes bay, thyme, rosewood, parsley seed and juniper.

When I created it, I wasn't interested in making a conventional floral body oil. I wanted the scent to feel much closer to being outdoors: green and herbal, but also earthy, woody and smoky. Bay became important because it gives the blend that recognisable aromatic greenness without making it feel sweet.

The carrier oils form the functional base of the product, helping to nourish and condition the skin, while the aromatic botanicals shape the experience of using it. Applied after bathing and massaged into the body, the intention is not to add another complicated step to someone's routine, but to make an ordinary one feel a little more considered.

That distinction between routine and ritual is important to Menteath. A ritual doesn't need to be elaborate or particularly spiritual. Sometimes it is simply doing something you already do with a little more attention.

What do we mean by Botanical Intelligence?

Botanical Intelligence is our new Journal series looking more closely at the plants and natural materials we formulate with.

There is an extraordinary amount of language around botanicals in beauty, but often very little explanation of the plant beyond a list of purported benefits. We want to look at the whole journey instead: where a plant grows, how it is harvested and extracted, what compounds have been identified within it, what scientific research can genuinely tell us, how it behaves within a formulation and, where relevant, what happens when we encounter it through scent.

It is also an opportunity to be open about what science doesn't yet tell us. Traditional use can be interesting without being treated as proof, and early laboratory findings shouldn't be presented as established clinical outcomes. Nature doesn't need exaggerated claims to make it interesting.

Bay is a good place to begin precisely because it is so familiar. Behind the leaf sitting quietly in the back of a kitchen cupboard is a Mediterranean evergreen with a distinctive aromatic chemistry, a long relationship with people and a very different life when distilled and incorporated into a modern formulation.

Over the coming months, Botanical Intelligence will explore more of the ingredients behind Menteath, including the juniper bark resin extract responsible for much of our characteristic smoky, woody scent, alongside the oils, botanicals and other materials that have shaped the products from the beginning.

Botanical Intelligence is a Menteath Journal series exploring the plants and materials behind our formulations, from their origins and extraction to their chemistry, skin function, scent and sensory experience.