Cannery A to Z: E is for Evaporator

What’s an evaporator and what is it doing in the Cannery ?

Beginning in the 1940s, the Gulf of Georgia Cannery operated as a herring reduction plant, where herring was mashed up and processed into fish meal (dry powder) and fish oil (liquid). While most of the machines used in the plant were “borrowed” and customized from other industries (like the hoppers from granaries, presses from wineries, separators from dairies), the evaporator machine was special-ordered all the way from Norway, where they were already being used to reduce their fish bi-products. It was so large that they had to move the roof up several metres so it would fit. Today, if you look up at the ceiling of the Evaporator Room in the Cannery, you can see a line along the wall where the old roofline used to be. This is as an important reminder to always check the dimensions of anything you order online!

Why was it worth making all these changes to the building to fit a machine that makes fish fertilizer? The evaporator was a specialist machine. It boiled liquid that came from the herring (called “stickwater”, which usually was thrown out), and turned it into a thick sludge (called “fish solubles”). These solubles were sold as a liquid fish fertilizer or added to fish powder to make a very nutritious herring meal for animal feed (yum!). Although fish fertilizer might not sound appetizing, it is a great source of nutrients for soil to help crops grow. Evaporators aren’t only used to make fish oil – they are also used to process foods that we eat. Check your kitchen for any juice concentrate or evaporated milk – these also went through an evaporator!

Posted by m.horita
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