How smells affect our taste
I have talked often about our sense of Taste, but in fact all five senses are involved in tasting, as Heston Blumenthal demonstrates so clearly through his tasting experiences, which might include sound played through headphones and certainly much visual trickery.
In this article I want to focus on the link between taste and smell. Whilst the basic taste receptors are contained mainly (although not exclusively) on the tongue they are just a trigger for the entire tasting process. About 80% of the experience is olfactory, i.e. linked to the sense of smell. The tongue is able to identify only 5- 7 basic tastes (the first 5, sweet, sour, salt, bitter and umami are by now well established, two further taste receptors on the tongue – fat and metallic, are still being researched). You will know that when you have a cold and your sense of smell is affected food doesn’t really taste of much. However when the nose is bought back into play we can experience tens of thousands of flavours. The words “taste” and “flavour” are, in common usage, pretty much interchangeable, but when talking about our total taste experience the first refers to what we experience via the tongue and the second to those experienced via the nose.
Our sense of smell is linked directly to our memory, whilst the rest of our senses have to pass first through the thalamus where they can be analysed. This means that our reaction to smell is based on raw emotions, a primitive safety mechanism enabling us to identify poisonous plants without needing to taste them. Professional wine tasters, sometimes referred to as “noses”, make great use of the olfactory senses to identify nuances of flavour, which they link to their own personal memories often to the confusion of the rest of us! For the cook, the strong emotions that smells evoke can be both a blessing and a curse, as we cannot predict when a smell has been linked to a negative memory. It is also known that your olfactory neurons, which are constantly wearing out and being replaced throughout most of your life, cease to replace themselves as efficiently when you get old.
Imagine how awful if must be for anyone who cares about food to lose their sense of taste prematurely. Molly Birnbaum lost her sense of smell (and therefore taste) following an accident. Over a period of years it did return, but in the interim she wrote her memoirs Season to Taste about the experience, and the renowned Elizabeth David also lost her ability to taste salt accurately following a stroke at the age of 49. The stroke was minor, and she kept it rather quiet, but the books that she began writing at this time (although not published until many years later) Spices, Salt and Aromatics in the English Kitchen and English Bread and Yeast Cookery were far more academic than the early writings that earned her fame for her ability to write so evocatively, conjuring up the tastes and smells from her travels abroad.
In the introduction to Spices, Salt and Aromatics in the English Kitchen Elizabeth David writes…
“House-bound during a temporarily incapacitating illness during the early nineteen-sixties I enjoyed my compulsory leisure re-reading old favourites in my cookery library”… Amongst these books was The Art of Gentle Cookery by Mrs Hilda Leyel, the founder of the Society of Herbalists and the Culpepper herb shops. Elizabeth wrote a tribute to her in The Spectator and it is clear that her writings of the spices and aromatics of the Levant touched a deep cord within Elizabeth, sufficient to sow the seeds for Spices, Salt and Aromatics in the English Kitchen. It must have been terrible for Elizabeth, who greatly feared losing her sense of taste to have this fear, at least in part, realised. Knowing the backdrop to the book increases its interest to me, although as Elizabeth herself admits it barely scratches the surface of the subject. The herb chapter of the book seems particularly shallow when read today, but that perhaps just illustrates how our use of herbs has grown since it was published in 1970. It also makes no mention of edible flowers, particularly those used for their aroma rather than just their visual appeal.
Aromatics in the Kitchen
Herbs and spices are the most frequently used aromatic ingredients in the kitchen and at this time of year (July) the full range of herbs are available as well as most edible flowers. Another reason to experiment now is that Summer is, predominantly, linked with positive memories, minimising the risk that what might be a pleasurable memory for you is the exact opposite for someone else!
Top of my personal list of scented culinary plants are: Lemon Verbena, Lavender, Rose and Scented Geraniums.
Lavender and Roses are, of course, widely grown for their decorative value, but can also be used in cooking. Lavender is part of the traditional mix known as “herbes de Provence” and in this form used in savoury dishes, but I tend to use Lavender on its own in sweet dishes. If you can buy Lavender honey (and are any of the increasingly common Lavender farms in the UK producing their own honey?) use the fresh buds to accentuate the delicate flavour, for example in an ice cream. A Provencal style iced nougat parfait would be my top choice.
To use rose petals in cooking you want the strongly scented Damask roses. These are usually, but not always, deep in colour as well as scent and were used in the past for scenting creams or Junkets – good for serving with soft fruit. The white triangle at the base of the petal is a little bitter so best removed by snipping it out with a pair of scissors, especially if it is quite large. Rose petals are also used other cultures, particularly the Middle East, where rosewater adds scent to food. A rose petal jam is a real delicacy. A few years ago I tasted one that was being made with wild roses by the Saxon Village Preserves in Transylvania. It was exquisite – one woman was reduced to tears, but I put this down to the strong link between smell and memory, I think it had evoked a happy childhood memory for her.
Flavouring sugar is a good way to keep either lavender or rose at hand for future use. For immediate use the flavours are usually infused in milk or cream which can then be used in a variety of ways, e.g. ice cream, pannacotta, junket.
My “signature dish” would be a dessert of hot fruit with a herb or spice ice cream. I have variations depending on the season, but at this time of year I am spoilt for choice, both of fruit and herb flavourings. There is however one combination that will definitely be used each year – an ice cream made of Lemon Verbena to accompany baked peaches. Lemon Verbena is not the easiest of herbs to grow, at least where I live, as it likes a lot of sunshine and a sheltered position. I grow it in a pot on the kitchen windowsill, but I know of people in Hampshire who have an outdoor bush about three feet high, so it does depend very much on where you live. Once you have used it you will never want to be without, but as an alternative you could try lemon thyme. Similar growing conditions are required for peaches, and if I was lucky enough to be able to grow them I would no doubt enjoy them straight from the tree. Baking them does however transform even a not-so-ready-to-eat supermarket peach.
Another plant that I tend to grow indoors, although it is perfectly happy outdoors in the summer, is scented geranium. Unlike the geraniums that are grown for their cheerful flowers, these are mostly leaves, although some of these are quite pretty in their own right, but the flowers if they come at all are pale and small. The scent is everything in these plants and there are a wide variety of different scents to choose from including. However my preference is for the rose-scented varieties – Graveolens, Lady Plymouth or Attar of Roses. Bringing the pots indoors enables you to over-winter the plants, although they are quite prolific growers, so that I do not see this as strictly a summer scent. I particularly like them with apples (I have given recipes for this here before) but the leaves have also been used to scent a Victoria Sandwich or cream for soft fruit – the scent is much stronger than rose petals alone.
Surprisingly many leaves can be used in cooking. It is usually the aroma that you are diffusing and it is often surprisingly reminiscent of the taste of the fruit or flower itself. Blackcurrant leaves are one example. When I was a child we had blackcurrant bushes large enough to hide in, and I frequently ate the fruit, raw, from underneath the bush. Now, whilst waiting for the fruit to ripen, I can recreate that experience by using the young leaves to make a sorbet.
Likewise many herbs produce flowers, which taste very similar to the leafy part of the plant. The aroma is not usually their main attraction, but they look pretty whilst also reinforcing the link with the more powerful smelling leaves. The flowering heads of fennel, for example, can be used in the same way as the frondy leaves and are particularly trendy at the moment – if such things bother you!
A trio of scented sorbets – Rose Geranium, Elderflower and Blackcurrant Leaf
Nectarine Tare Tatin with Lemon Verbena Ice Cream
Rose or Lavender scented sugar