Wood Bread

Wood Bread

By: Jani Anders Purhonen (Helsinki)

This bread honours Finland’s Pettu tradition, a practice where inner layers of pine bark were used to supplement rye flour during times of scarcity. Historically, Pettu bread sustained people during the famines of the 1690s, 1860s, and even the 1918 civil war.

While it was once used as a rye substitute in larger quantities, modern recommendations suggest using Pettu at no more than 10-20% of the flour mixture to ensure it remains easy on the stomach. Interestingly, even at concentrations as low as 5%, the distinctive taste of pine bark is present without compromising the bread’s texture.

This sourdough recipe also incorporates acorns, harvested during forest thinning, which complement the fresh, woody aroma of the Pettu with a rich, caramel-like roasted flavour. Together, these ingredients enhance the bread’s fibre content, offering a nutritionally rich and nuanced rustic flavour of Finnish forests.

Ingredients

500 g wheat flour
40 g pine bark flour
40 g acorns (after boiling/washing, peeling, crushing)
440 g water
100 g sourdough starter
12 g salt

Method

To prepare the acorns, start by washing them with cold or hot water to reduce the tannins to edible levels. The amount of processing depends on how long the acorns have soaked in rainwater. Generally, rinse the acorns under running water or boil them (with or without salt) until the water is no longer brown. If using salt, you can reduce the amount in the final recipe. Once clean, roast the acorns at 200°C for about 10 minutes to enhance the flavour.

To prepare the Pettu, gather the layer between the pine bark and the “nila” layer, typically available in late May or early June. Scrape this layer from felled trees (with permission) using a spatula. Dry the pettu in the sun or over a hearth, then roast it at 185°C to remove resins and other unwanted substances. Once roasted, grind the Pettu into a fine powder.

For the bread, start by mixing the dry ingredients (except the acorns) with water and kneading for 15 minutes. Let the dough rest until the sourdough starter is refreshed. To check if the starter is ready, take a spoonful and see if it floats in water. When it floats, stir the starter into the dough and let it rest for half an hour.

Fold the dough every hour for about 4 hours or until it has risen by 50%. After the final fold, incorporate the roasted acorns and shape the dough for the rising basket. Allow the dough to rest in the fridge for 12 hours to 2 days.

Preheat the oven to 260°C and score the dough to release gases during baking. You can be creative with the scoring, perhaps shaping it like a tree. Transfer the dough to the oven, add a piece of ice for steam, and reduce the temperature to 220°C. Bake for at least 40 minutes, then serve.

The Wood Bread by Jani Anders Purhonen won the main prize of Maaleipä Challenge. The jury described the bread in the following way:

The Maaleipä awarded the first prize is a bread combining past and future, taking an ingredient created in times of scarcity and transforming it into a flavour of ecological biodiversity and flourishing for future generations. It is a bread that encourages people to engage with the forest, reduces waste, and supports farms to integrate oak into cultivation of food-forests. In line with more ecosystem thinking, it’s a bread that expands what farming, food and land use should be in Finland and what we should all be eating. The wonderful sourdough is delicious, has a deep taste and a beautiful appearance.