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Earliest Evidence of Fermenting vessels

Posted July 1, 2019

Hello Friends and Fellow Fermenters,

It’s lovely to be writing to you again! It is particularly exciting because this installment is coming from our newly remodeled studio. It has been a full spring here at InFerment, and I’m excited to share all of the new developments. This post will be split into three parts- I’ll begin with the news, then we will go back in time and learn about the earliest evidence of fermentation, and finally more details about the available fermentation workshop and newly offered ceramics classes.

InFerment new clay-space with 16-years-old Ulu who loves the new open feel.


  • First, we have a new clay-space! We’ve just completed a significant remodel of our studio, opening the space up to provide a better flow of energy and light during production, and to allow for more people to work with us. We will be offering ceramics classes starting in August for children, and in September for adults. We hope you will join us!
  • InFerment has been featured in Wired magazine! Local Seattle author, Joe Ray, visited the studio to interview fellow ceramicist Erik Painter and me. We had a vibrant discussion about fermentation and ceramics, which led to a warm connection, while Joe made fast friends with Ulu, my 16-year-old dog. Check out Joe’s fascinating articles about fermentation.
  • In an exciting new collaboration, we are partnering with chef and farmer Elisabeth Marshall for a fermentation workshop and meal at Full Bloom Farm on Lumni island on August 24th. More details can be found below. 
InFerment is featured in Wired magazine article written by Joe Ray.

Now let’s go back to our mission of this newsletter series: introducing early historical fermentation and its relation to ancient ceramic vessels.

In the first post, we talked about 9,000-year-old traces of beer-wine found in ceramic vessels in Jiahu, China, and the 8,000-year history of Georgian winemaking in giant ceramic pots called Kvevri. Then, we moved to the Ulúa Valley of Mesoamerica, around 1100 BC in what is now northern Honduras, where we picked up the earliest threads of humans using cacao – the plant we know as the basis for chocolate  (I’d be happy to send these previous posts to any new subscribers).

Today, we’re going to visit Sweden to see the earliest known evidence of fermentation for food preservation. A large-scale deposit of fish bones was discovered in a mud pit on the east coast of Sweden that dates back to the Mesolithic period, about 9,200 years ago

Traditional Swedish fermented Herring with the pile bones Adam Boethius Early Mesolithic settlement.

The Mesolithic period, which spans around 10,000-5,000 BC, marks the time before people started farming in Europe. People survived by hunting, gathering, and fishing, and needed to follow their food sources. This pit, full of some 200,000 fish bones suggests that people during this time were actually more technologically and culturally advanced than assumed. Adam Boethius, the author of the study from Lund University, suggests that having the capacity to store a vast amount of fish in one place by fermenting them allowed people to start settling much earlier.

Adam Boethius and his colleagues found the pit full of bones.

In 2011, Boethius was excavating a site at Norje, Sweden with 16 other archaeologists to rescue artifacts from Early Mesolithic settlements before a road was being built. As they started to dig, they found a lot of fish bones. They then uncovered an elongated pit, or gutter, surrounded by small stake holes and completely filled with fish bones. Boethius analyzed the contents and discovered the fish bones were from freshwater fish that had been fermented, a skillful way of preserving food, and this time, without using salt as done in curing. Scientists estimated that at least 60,000 tons of freshwater fish were processed at the site.

Dr. Boethius explains the process of fermenting at the site by not having access to salt and yet be able to make ceramic containers. They, Boethius describes, acidified the fish with pine bark and seal fat, and then wrapped the entire content in seal and wild boar skins and buried it in a pit covered with muddy soil.

InFerment water seal fermenting vessel and a view of the 7,200 BC gutter with stakeholes and clay surrounding it at Norje.

It seems to me that the gutter shape, which was dug and covered with clay-mud, functioned similarly to the modern ceramic vessel only laying horizontally underground. In the pits, the fish was protected from harmful bacteria allowing it to be nutritious for the coming months.

This is another beautiful demonstration of the symbiotic relationship between clay (mud), food, and health!

More Details

Ceramic summer camp:

August 12th-16th ages 5-11 years old 9:00am-3:00pm our work will follow the theme “Embracing Endangered Animals” email [email protected] for more information

Fermentation workshop:

August 24th we’ll have a collaborative event at Full Bloom Farm at Lumni Island.
While enjoying the beautiful scenery of the farm, we will learn the historical and cultural aspect of fermentation and then make our own fermented food in InFerment ceramic fermenting vessels. We will also be treated tasty food that owner of the farm and chef Elisabeth Marshall will prepare for the class participants. Stay tuned for more details!


Kids clay class will open in September 2019 Wednesday 3:30pm-5:30pm ages 6-12 years old. Session of 6 classes.
Adults classes will open in September 2019 Tuesdays 6:30pm-9:00pm. Session of 4 classes.