What is Scots pine (inner bark)?

Scots pine inner bark is the soft, pale layer just under the rough outer bark of Pinus sylvestris. In Finland it is called pettu. It was dried, roasted and ground into a coarse flour.

The tree grows across northern Europe. Finnish, Swedish, Norwegian and Sami households used the bark as a hunger food when grain was short. Today small amounts are sold as a speciality flour, a tea or a baking flavour.

Here is the honest verdict. There is almost no human research on eating Scots pine inner bark. The tradition behind it is long and well recorded, but tradition is not proof that something works, and it is not proof that something is safe.

How does Scots pine (inner bark) work?

Most of what the bark does in the body is probably down to fibre. The inner bark is largely plant fibre that you cannot digest. In hard times it added bulk and filled out scarce grain.

It holds little protein and little usable energy. So it fed people by stretching flour, not by being nourishing on its own.

In test-tube studies, pine bark extracts show antioxidant activity (they mop up reactive molecules). Some lab work also finds they slow the growth of certain bacteria. Whether any of that happens inside a human body is not established.

Pine tissues contain some vitamin C. Vitamin C prevents and treats scurvy, and that is settled science. But the amount in the inner bark swings with season, tree and handling, so it cannot be counted on as a source.

One point of confusion is worth clearing up. Most published "pine bark" research uses maritime pine bark extract, a standardised product from a different tree. Those results do not carry over to Scots pine inner bark eaten as food.

What forms does Scots pine (inner bark) come in?

You are most likely to meet it in one of these forms:

- Pettu flour: dried, ground inner bark, sold in small bags in Finland and Sweden. - Bark bread and crispbread: baked goods using a share of bark flour with rye. - Bark tea or infusion: shavings steeped in hot water.

You may also come across:

- Dried strips or shavings, sold for cooking or crafts. - Foraged fresh bark, scraped from a felled or permitted tree in spring.

Pine essential oil, pine needle oil and turpentine are different products. They are not food. Do not treat them as a form of this remedy.

Where it comes from:

Scots pine inner bark was a known hunger food across Finland, Sweden, Norway and Sami areas. Written records go back centuries. Its use spread widely during the Finnish famine years of the 1860s.

Bark was taken in spring, when the sap was running and the layers parted easily. The inner layer was dried, leached, roasted and milled. The flour was then stretched into rye bread when grain ran out.

Sami households also stored the bark as a food and used it to flavour or wrap other foods. Folk practice in Finland and Sweden included bark tea for coughs and for winter health. These uses were written down by folklorists and travellers of the time.

What does Scots pine (inner bark) help with?

• Famine or emergency food, to stretch flour: This is the use the tradition truly rests on. Bark flour padded out rye when grain ran short. It works as bulk, not as nutrition. The bark gives little protein and little usable energy. People who lived mainly on it still went hungry and still got ill.
• Everyday fibre in bread and porridge: The inner bark is mostly fibre, so a bread made with it is a high-fibre bread. That part is simple food chemistry. No trial has tested pettu flour for bowel health or any other outcome. If you want more fibre, ordinary whole grains, beans and fruit are far better studied.
• Traditional use for coughs and sore throat: Bark and needle teas were taken in Nordic folk practice for winter coughs. The warm drink itself may feel soothing. There are no human trials of Scots pine bark tea for cough. Any benefit may be the warmth and fluid rather than the bark.
• Traditional use against scurvy in winter: Northern households used pine parts, mainly needles, when fresh food ran out. Vitamin C does prevent and treat scurvy. The catch is the bark itself. Its vitamin C content is low and swings widely with season and handling. It is not a reliable source, and scurvy today needs proper treatment from a doctor.
• Traditional flavouring in Nordic baking: Small amounts of pettu flour give a resinous, slightly bitter taste to bread. Some Nordic bakers use it for that reason alone. This is a culinary use. No health claim is being made here, and none is supported.

Which foods are rich in Scots pine (inner bark)?

Scots pine inner bark is itself a food. It is not a nutrient found in other foods.

What are the side effects of Scots pine (inner bark)?

• Bloating and wind
• Stomach cramps
• Constipation if you drink too little water
• Loose stools in some people
• Dry, puckering mouth from the tannins
• Bitter or resinous aftertaste
• Skin rash from handling fresh resinous bark
• Allergic reaction in people sensitive to pine (rare)

Good to know:

Most problems are gut problems, and they come from the fibre load. They are mild and settle when you stop.

Serious reactions are rare. The ones that matter are allergy and poisoning from the wrong material, such as bark from a treated or misidentified tree.

Safety in pregnancy and breastfeeding has not been studied. Safety in young children has not been studied either.

How much Scots pine (inner bark) should you take?

• Recommended daily: Scots pine inner bark is a food, not a medicine, so no medical dose exists. Packets of pettu flour usually suggest using it as a small share of the flour in a recipe. A quarter or less of the total flour is a typical label figure. That is what labels carry. It is not an instruction for you, and no research supports any particular amount.
• Best time of day: Timing does not matter. It is eaten as part of a meal, like any flour. If you do use it, drink water with it. High-fibre foods sit badly when you are short of fluid.
• With or without food: It is food, so it goes with food. Bark flour is baked into bread, crispbread or porridge. Bark tea is usually drunk warm, on its own or with a meal. Either is fine.
• Time to effect: Any effect you notice is likely a bowel effect, and that would show within a day or two. For the older claims, about coughs or winter health, there is no honest timeline to give. It may do nothing at all.
• How long to take it: No study has set a safe length of use, so no sensible limit can be quoted. In famine years people ate bark bread daily for months. That was survival under pressure, not a model to copy. As a flavouring in baking, it is used the way any other speciality flour is used: now and then.