Fermented Oats — The Forgotten Wisdom of the Herbal Kitchen

There is something rather wonderful about discovering that an ordinary ingredient, one that has probably sat in our kitchen cupboards for years, has a history extending far beyond its familiar everyday use.

What interests me most about fermented oats is not simply their nutritional composition. It is the story they tell about the relationship between people, plants, food and health.

Across different countries and cultures, generations of people developed ways of preparing oats that suited their circumstances and needs.

Some preparations provided everyday nourishment. Others became associated with digestive complaints, recovery from illness or maintaining health.

This knowledge was developed through observation, experimentation and repeated practical experience.

Today, researchers are beginning to investigate some of the biochemical changes involved in these traditional preparations.

There is still much to discover, but the renewed interest in fermented oats demonstrates the value of looking carefully at knowledge that has been handed down through generations.

As a medical herbalist, I believe traditional herbal knowledge and modern scientific investigation have much to contribute to one another.

Both can help us understand the remarkable potential of the plants and foods that have sustained people for centuries.

And sometimes, that exploration can begin with something as simple as a handful of oats.

Most people associate oats with porridge, oatcakes or breakfast cereals. Yet, long before modern food manufacturing, oats were valued not only as a substantial food but also as an ingredient in traditional household medicine.

Across Britain and Eastern Europe, communities developed methods of fermenting oats into sour porridges, nourishing gruels, drinks and other preparations.

Many of these traditions have almost disappeared, but their history offers a fascinating insight into the relationship between food preparation and traditional healthcare.

Oats in Traditional Herbal Medicine

The common oat, Avena sativa, has an established place in Western herbal medicine.

Herbalists traditionally distinguish between the different parts of the plant and their applications.

Milky oat tops, harvested while the developing grain is still soft, have long been valued as a nourishing nervous-system restorative, particularly in traditional approaches to exhaustion, stress and convalescence.

Oat straw has also been employed in herbal infusions and other preparations associated with nourishment and restoration.

The mature grain, however, has a somewhat different history.

Oatmeal, oat gruels and other preparations made from the grain were traditionally used to provide nourishment during illness, weakness and recovery.

In his nineteenth-century work The Elements of Materia Medica and Therapeutics, Jonathan Pereira described oatmeal gruel as a nutritious, easily digested preparation used during fevers, inflammatory illnesses and after childbirth.

He also discussed its demulcent properties.

A demulcent preparation has a soothing quality when brought into contact with irritated tissues. The soft, somewhat mucilaginous consistency of cooked oatmeal helped establish its place among traditional nourishing preparations.

The medicinal history of oats therefore extends well beyond the familiar modern discussion of dietary fibre.

Why Did Our Ancestors Ferment Oats?

Fermentation is one of humanity's oldest methods of transforming food.

Long before microorganisms were understood, people observed that certain foods changed when left under suitable conditions.

Some became pleasantly sour. Others developed new textures, flavours and keeping qualities.

Through observation and experience, communities refined these processes and passed their knowledge from one generation to the next.

In the case of oats, fermentation occurs when microorganisms act upon components of the grain, producing organic acids and other substances.

These changes can influence flavour, texture and the availability of certain nutrients.

For traditional households, fermentation offered a practical means of transforming grain into a variety of foods, some of which also acquired reputations as household remedies.

Scottish Sowans — A Forgotten Traditional Food

One of the best-documented examples comes from Scotland, where households prepared a fermented oat dish known as sowans, also written as sowens or sooans.

Traditionally, oat husks and small particles of meal remaining after milling were steeped in water and allowed to ferment. The soured mixture was strained, and the settled starchy portion was collected and cooked into a smooth, slightly tangy porridge.

The remaining liquid, known as swats, could also be used.

Sowans were an important part of rural cookery, but they also had a place in domestic medicine.

Accounts from Orkney record their traditional use for stomach complaints, demonstrating how a familiar food could also be regarded as a household remedy.

Today, researchers are investigating the preparation and fermentation of sowans while working to preserve this increasingly rare traditional knowledge.

Oat Kissel — A Traditional Nourishing Preparation

Another fascinating preparation comes from Eastern Europe, particularly Russia and Belarus.

Traditional oat kissel, or kisiel, was prepared by fermenting crushed oats or oatmeal in water. The soured liquid was then strained and heated until it thickened into a smooth gruel or jelly.

Unlike the sweetened fruit versions familiar today, traditional oat kissel was a substantial fermented cereal food.

Its soft consistency made it particularly interesting as a form of gentle nourishment, while its preparation illustrates the historical importance of fermented grains in everyday cookery.

For herbalists, such foods offer an interesting connection between traditional nourishment, preparation methods and the wider practice of maintaining health through diet.

Other Fermented Oat Traditions

The practice of fermenting oats was by no means restricted to Scotland and Russia.

Ethnobotanical research published in the Journal of Ethnopharmacology in 2015 documented several traditional fermented cereal preparations across Eastern Europe.

Among them was bexhin, a fermented oat preparation associated with Circassian families living in Kosovo.

Traditionally, oat grains were roasted and allowed to ferment in water before being heated to produce a thick preparation.

Bexhin was particularly associated with older members of the community and was traditionally regarded as a health-giving food, including a reputation for helping to protect the heart.

This recorded belief is an interesting part of its medicinal food heritage.

The same research documented fermented oat drinks and gruels in Estonia, including preparations known as kile, kiisel and related names.

Some were consumed as sour drinks, while others were cooked into thick gruels or allowed to set into a jelly.

These examples reveal the remarkable variety of fermented oat preparations developed across different cultures, many of which are now rarely encountered.

What Does Fermentation Actually Change?

From a herbalist's perspective, one of the most interesting questions is how fermentation alters the properties of the grain.

Oats naturally contain carbohydrates, proteins, minerals, dietary fibre and numerous plant compounds.

Among their better-known constituents are beta-glucans, a type of soluble fibre, and phenolic compounds, including avenanthramides.

Fermentation can influence several of these constituents, depending upon the preparation.

Phytic Acid and Mineral Availability

Oats naturally contain phytic acid, which can bind minerals such as iron and zinc.

Under suitable fermentation conditions, enzymes can break down some of this phytic acid.

This may improve the availability of certain minerals, although the extent of the change depends upon the oats, microorganisms and fermentation conditions.

Plant Compounds

Research has demonstrated that fermentation can influence the availability of certain phenolic compounds within oats.

Some microorganisms produce enzymes capable of releasing compounds previously bound within the grain.

This is particularly interesting because oats contain a variety of naturally occurring phytochemicals with biological activity.

Fermentation may therefore alter not only the flavour of oats but also aspects of their chemical composition.

Digestibility

Fermentation can change the structure of starches, proteins and other components of the grain.

These transformations may influence how a fermented preparation behaves during digestion.

The effects vary according to the fermentation process, and different methods do not necessarily produce identical nutritional changes.

Modern investigations into these processes provide an interesting opportunity to examine some of the changes associated with longstanding traditional food preparations.

Different Ways of Fermenting Oats

Not all fermented oats are prepared in the same way.

The microorganisms involved, the temperature, the length of fermentation and the type of oats used can all influence the finished preparation.

Wild fermentation: This traditional method relies upon microorganisms naturally present in the ingredients and their environment. Scottish sowans and some traditional oat gruels were prepared in this way.

Sourdough fermentation: An established sourdough culture introduces yeasts and lactic acid bacteria into an oat-based batter. This method can be used to make fermented oatcakes and other baked preparations.

Lactic acid fermentation: Selected lactic acid bacteria are introduced into an oat preparation, allowing greater control over the fermentation process. Such methods are used in the production of cultured oat foods and drinks.

Fungal fermentation: Certain food-grade fungi are used in specialist grain fermentations. Their enzymes can transform components of the oats, producing changes in texture, composition and flavour.

One particularly interesting discovery from modern research is that heat treatment can influence the way oats ferment.

Oats that have undergone certain heat-processing methods may have less active natural enzymes than untreated oat grains.

These differences can affect the progress of fermentation and the biochemical changes that take place.

This helps explain why reproducing older fermentation methods with modern ingredients may not always produce exactly the same results.

Fermentation and the Herbal Kitchen

Within herbal practice, the method of preparation has always been important.

A plant can produce quite different preparations depending upon whether it is infused, decocted, extracted in alcohol, preserved in vinegar or prepared in another way.

Fermentation introduces a further dimension.

It is a biological transformation in which microorganisms and their enzymes can change aspects of the original ingredients.

Understanding these processes allows us to appreciate both the traditional uses of fermented foods and the chemistry behind their preparation.

It is also important to distinguish controlled fermentation from uncontrolled spoilage. Anyone preparing fermented oats at home should use a properly established method with suitable fermentation conditions and food safety practices.

Fortunately, there are ways to introduce genuine oat fermentation into the modern kitchen without attempting to recreate more complicated historical methods.

The humble oat has a remarkable history, extending from everyday nourishment to its place within traditional herbal and household medicine.

By rediscovering preparations such as sowans, kissel and fermented oatcakes, we can preserve a little of that knowledge and bring it back into our own kitchens.

Ann the Herbalist
Exploring traditional herbal medicine, forgotten foods and the wisdom of the kitchen garden.