Freedom Hygiene was approached by Farne of Scotland to minimise the presence of Listeria within the food processing equipment in its cold and hot smoke salmon plant.


Farne Salmon is the largest cold and hot smoke salmon manufacturer in Europe, producing a wide variety of the ready-to-eat and ready-to-cook salmon and delivering best brand salmon products to its customers.

Due to the cold smoke production process, products are vulnerable to contamination by pathogens including Listeria monocytogenes.  With cold smoking facilities, the only conventional line of defence is a salting process.  At Farne Salmon, sporadic Listeria spp. spikes were being found, especially on the cold smoke and added value products.


For several years, Farne has noticed sporadic finish product Listeria spikes but its Listeria environmental sampling plan didn’t indicate any issues or areas where microorganisms could be harboured during cleaning.  All post-clean micro and ATP results (<50RLU) were good and no issues were noticed with cleaning results and methodology.

Like most open plan food manufacturers Farne used chlorinated and acidic products to clean and to control the growth of microorganisms.  Biofinder, as recommended by Freedom Hygiene, helped us to identify hot spots where there was a significant build up of biofilm.


  • Open plant enzymatic treatment: A two component formula, using Biojet and Enzyjet Plus (shock treatment)
  • Manual foaming after a standard detergent treatment to equipment and plant using a 0.2% Biojet and 1% Enzyjet Plus solution with a minimum of 20 minutes contact time with manual padding.  After the desired time, all enzyme residue was rinsed off and surfaces retested with Biofinder showed a 90% reduction in biofilm deposits.  All cleaned surfaces were sanitised with PAA at 1%. The treatment was repeated with a more in-depth equipment strip down to allow better enzyme penetration.
  • Enzybasic, used fortnightly – all equipment with visible biofilm formation was treated with up to 3% Enzybasic solution with a minimum contact time of 20 minutes (open plant foaming) and small items including whizzards, knifes and blades were submerged and soaked in 1.2% Enzybasic solution for a minimum of one hour (resulting in a direct cost reduction).

A visible and noticeable environmental and finished product improvement in micro and Listeria downtrend detections in two main departments. 0% Listeria detection in added value finish products (cold smoke salmon, cheese and creams main ingredients) and no product end-of-life detection in cold smoke salmon (sliced product).  No finish product Listeria OSS from November 2018 onwards.


  • Daily use of Biofinder allowing to trace biofilm formation
  • Periodical and as needed enzymatic open plan treatment to prevent biofilm reappearance after main detergent cleaning to maintain costs
  • Weekly soak cleaning of all production equipment i.e. whizzards, knifes, spatulas and tools using a 1.2 % Enzybasic solution with longer contact time