Cucumber has been a faithful companion in salmon dishes for a number of years, and there’s a reason for that: the salmon actually goes through processes which makes cucumber a particularly good match.
Many in Norway have grown up with boiled salmon and cucumber salad as a staple for fancy occasions. Whether you’re eating sushi in maki rolls, a salmon wrap or the trendy dish poke, chances are that you will find cucumber alongside salmon.
Cucumber is particularly suitable for salmon due to processes that happen in the salmon after it is slaughtered. To understand why, we need to take a deep dive into the world of biology.
Nature has its way
All food undergoes changes after it is harvested and stored. Nature disposes of dead plants and animals by breaking them down, and that’s what happens when our food gradually goes off. There are several ways to delay this process in order to keep the food fresh for longer, but sooner or later, decomposition processes will kick in.
When we assess the quality of the food we are going to eat, we are really looking at how far into the decomposition process it is. Our sense of smell is an important tool in this regard.
Salmon undergoes major changes immediately after it dies. The heart stops beating and will no longer transport oxygen and nutrients into the muscles. The muscles use up their energy reserves and convert them into lactic acid, which in turn lowers the pH of the muscle.
This lower pH activates lysozymes in the cells – small “suicide packs” with enzymes that flow out and start decomposing the fish. Since the salmon’s immune system is completely deactivated, bacteria also start growing which accelerate the decomposition process. In addition, the fat in fatty fish turns rancid when it reacts with the oxygen in the air.
All these processes create different odours that we can use to determine how fresh the fish is.
It smells like cucumber!
One of the substances that forms when fat reacts with air are aldehydes, which we also find in many perfumes. These often have a characteristic smell, and one of these aldehydes smells just like – you guessed it: cucumber.
The cucumber smell is one of the first odours you can smell from a salmon, which indicates something has started to happen in the fish.
Sensory professionals with well-trained noses who work to assess different food products based on taste, smell and other sensory impressions often use a scale from 0-3 when they assess the smell of salmon. If it is given a grade of 0, it means the salmon is completely fresh, but if it smells of cucumber, it gets a grade of 1. Salmon that smells of cucumber is thus still fully edible, but processes have started which will eventually turn the salmon bad.
The fact that the cucumber became a natural accompaniment to the salmon might therefore be related to the fact that the two raw materials smell the same at an early stage in the salmon decomposition process.
It is difficult to find evidence of whether their shared cucumber smell has been a deliberate trick to conceal that the salmon isn’t completely fresh, or if the smell has contributed to a subconscious desire to bring the two ingredients together. Either way it may help explain why so many find cucumber to be a perfect companion for salmon dishes.
Try for yourself!
The next time you buy salmon, try to see if you can detect the smell of cucumber. If you do, now you know why.
If you want to try out the combination of salmon and cucumber, we recommend the recipe below, which is prepared by advisor and Nofima chef Stian Gjerstad Iversen. Salmon with cucumber salad is a traditional festive dish, and here you can enjoy a variation using baked sugar-salted salmon and dill sour cream.
Recipe: Salmon with cucumber salad and sour cream
600 g salmon fillet
120 g salt
80 g sugar
2 bunches of dill
1 tbsp olive oil
- If you use wild salmon: freeze the fish one day in advance, and then thaw it.
- Trim the fish fillet so that you can cut it into neat pieces later. The fillet should be free of skin and bones.
- Mix the salt and sugar, and cover the fish fillet with the mixture on both sides on a platter. Cover the platter with cling film and place it in the refrigerator for half an hour.
- Remove the fish and rinse off the sugar and salt mixture under cold running water. Pat the fillet thoroughly with kitchen paper until the surface is dry.
- Cut the fish into portions of your own choice.
- Preheat the oven to 50°C (with thermal fan).
- Spread baking paper on a baking tray and arrange the fish on it. Sprinkle chopped dill, black pepper and olive oil over.
- Insert a cooking thermometer into one of the pieces of fish so you can monitor its internal temperature.
- Put the tray into the oven and bake until the internal temperature of the fish is 40°C, which takes around 40-50 min. Then take the fish out of the oven.
- You can then choose to either refrigerate the fish for later use or serve it immediately. If you are planning to serve the fish later, you should allow it to reach room temperature before serving.
1 tablespoon vinegar 7%
1 tablespoon sugar
2 tablespoons water
- It is recommended to prepare the cucumber salad just before serving, as the crisp texture and colour of the cucumber will be preserved.
- Mix vinegar, sugar and water in a bowl, and stir until the sugar has dissolved.
- Wash and cut the cucumber into thin slices.
- Put the cucumber slices in the vinegar water and mix well.
Dill sour cream
½ container of sour cream
4 bunches of dill
1 tbsp olive oil
Juice from ¼ lemon
Salt and pepper
- Remove the stalks from the dill and chop the leaves.
- Mix the dill, sour cream and olive oil with the lemon juice.
- Season with salt and pepper.