Dominion Salt – Invitation to view the salt harvest, April 2014


Above Robin Piggott of Dominion Salt is seen discussing salt harvesting with Rowan Bell of LASRA using a sample of this year’s crust.


Rowan and Geoff were invited to view the Lake Grassmere salt harvest in Marlborough and had a thoroughly interesting and educational time in the company of their convivial hosts, Robin, Brett, Tracy, Robert, Kevin, Gavin and Peter.


What an important part of our business salt is, and the production of solar salt turns out to be a fascinating process. It involves patient concentration of sea water through a series of evaporation ponds where concentration increases until it reaches that of a near saturated solution. It is then transferred to a series of crystallising ponds where the final crust forms which is then harvested in early autumn each year.


Whilst Grade 23 Stoved Salt is a big part of the story, salt finds a host of applications in a broad range of industries including agricultural fertilisers, animal supplements, casings, cheese production, paper, table salt and medicine.


After harvesting the salt, it is washed, stacked for several months to drain off the bitterns (Magnesium and Calcium Sulphate); then rewashed, crushed, dried, sterilised and screened. Further special processing prior to packing may be necessary depending on the intended market including the addition of anti-caking agents and mineral supplements.


With the introduction of specialised lines to their production such as flaky sea salt for culinary use and with plans to increase production capacity in the evaporation ponds there is a positive future look to our sole domestic salt producer.