Case Study 4 

Fuel Oil Damage to Malting Barley

Malted Barley shipped from Northern Europe arrived safely in port. However, when offloading commenced a large amount of fuel oil was splashed all over a number of the containers. There was clear evidence of a strong diesel smell in the area but it was hot whilst unloading in fine weather and the stevedores thought they could unload and let the oil evaporate and the smell dissipate. After the containers were off-loaded the dark residue caused by the oil could be clearly seen. hence it was deemed appropriate to try to wash the oil  residue off the containers using a detergent solution.

When the containers arrived at the brewery the head brewer immediately determined that it was not good practice to have tried to deliver the containers which had been contaminated. It was considered unsafe to try to use the malt inside in case of contamination. The ship owner was of the view that malt inside was usable because the containers were in good condition and there was no chance that the diesel oil could have entered into the container.

The cargo value was around £50,000 but the beer that could be brewed from this would have a potential retail value of up to £10M. 

Maltdoctor was consulted to work with the brewer in the presence of a representative of the shipping line to determine if the malt inside was contaminated and what the potential risk was if the malt was used in brewing.

Containers were opened one at a time and an initial aroma check on the inside of the containers revealed low level oil-based aromas on the container liner. Samples of malt were taken using a sampling spear and randomly checked later in triangle sensory tests for any abnormal aroma. Due to the time between the oil spill and sampling the levels were exceptionally difficult to detect, but there was some significance in a number of tests that the malt in the containers had a different aroma to the control malt which was an uncontaminated sample of the same batch.  It seemed that it was possible for the diesel oil vapour to have penetrated the container seals. Was this likely? How could that theory be proven? Interestingly on opening one of the containers a very strong detergent smell was detected. Maltdoctor had not been told if any of the containers was the one that had been washed, yet samples from this container clearly had a detergent-like aroma and indeed this container had been washed externally to try to remove the oil, which showed that external aromas could get into the container and contaminate the malt. There was no possibility of using this malt to brew with.

For the other containers it could not be guaranteed that the low level aroma of oil-vapour damage would not be detected if brewed with. Additionally these containers had certainly not been handled in a manner suitable for food-based products.

The risk was deemed too great to use any of this malt and Maltdoctor recommended that the brewery decision to reject the malt should be upheld.

 the UK barley