This is the 12928th most frequent Swedish word.
susen
"The trick" or "the solution."
The word 'susen' is used idiomatically here to mean 'the trick' or something that provides an optimal solution to a situation.
En kopp varmt te gör alltid susen.
A cup of hot tea always does the trick.
Here, 'susen' is again used idiomatically to indicate 'what worked' or 'the perfect solution' to the context.
Efter många försök hittade jag receptet som gjorde susen.
After many tries, I found the recipe that worked perfectly.
In this sentence, 'susen' conveys the idea of reaching an effective outcome or result positively impacting the overall situation.