Making Norway’s most dangerous sausages

They are making cured sausage here with enough bacteria to kill thousands of people - with the blessing of the entire Norwegian meat industry.

This article was last updated more than two years ago.

There is a tense atmosphere in the lab. Seriousness. Concentration. During the course of the day these researchers will be making about 50 cured sausages containing dangerous E. coli bacteria – specifically enterohemorrhagic E. coli (EHEC). Highly coloured pieces of tape are attached to the table. Forms for filling in all stages of the process are made ready. Do we have enough sausage skins? Is the end sealed up? Off we go then.

How does E. coli survive?

The FermSafe research project has been going on since the winter of 2007. "During the first phase there was a lot to get into place. When we were building up the lab, we had to obtain the equipment and test it out, as well as finding suitable methods. It probably took more time than we thought it would, but it was very important," explains researcher Even Heir.

The process of making cured sausage is complicated and many factors affect quality and safety. "For this reason we have tried to take a broad approach to finding out what could give us safer cured sausages. We made many trials in order to investigate the factors that affect the ability of dangerous E. coli to survive, both during the process and in the sausages themselves after they have been made," explains Heir.

High pressure may provide the answer

The researchers investigated which factors had the greatest significance. The effects of different quantities of salt, nitrite and sugar and of different fermentation temperatures were all tested.

"The method was important because our capacity for making E. coli sausages is limited. We have just finished a batch, part of which will be sent to Spain for high pressure treatment. It will be exciting to see whether this technique will be as effective in killing E. coli as we hope. We have also carried out initial trials using heat treatment and storage, to see how E. coli survives in the sausages," explains the researcher.

The most dangerous

"What conclusions can you draw so far?"
"Both process and ingredient parameters affect how safe the sausages are. Sausages with a high level of nitrite, salt and sugar develop less E. coli. Storing the sausages after they have been made can also have a useful effect. We must also test how the combination of the different parameters can be optimised," says Even Heir.

"What has the biggest challenge been?"
"There have been many of them! Nobody has ever made sausages as dangerous as these before – at least not in Norway. That sets especially strict requirements for good routines and planning all activities," says Heir. Very many factors affect how safe the sausages are.
"The biggest challenge of all is to combine these in the right way," says the researcher.

Pictures: The E. coli bacteria were originally isolated from two different outbreaks linked to cured sausages. Researcher Even Heir injects a bacteria solution into Ahmed Abdelgani’s meat mixture.

Several samples are taken from each sausage for analysis. Annette Wold Åsli proudly displays the new WASP, or Whitley Automatic Spiral Plater. This is a device for counting bacteria.

Three-day-old sausages are hung to mature

Senior researcher Askild Holck becomes a sausage maker for the occasion, while engineer Ahmed Abdelgani makes the next batch of meat ready in the background.

Contact: Even Heir


This research project started in winter 2007 and is 80% publicly financed and 20% by the industry itself. The public contributions come from the Research Council of Norway (52%) and the Foundation for Research Levy of Agricultural Products and research funds from the agricultural agreement (48%). Gilde/Nortura, The Norwegian Independent Meat and Poultry Association and the Federation of Norwegian Meat Industry are the contributors from the industry.

Almost 10 million kroner has been allocated to the project, which also involves Animalia, the Norwegian School of Veterinary Science and Nofima Mat. In FermSafe, sausages are being made that are deliberately infected with EHEC. To enable this, Nofima Mat at Ås has built up a mini pilot plant for pathogenic (disease causing) bacteria.

 Food safety and quality  

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