Changing search to support characters such as ÅÄÖ

Site URL: https://www.matochpyssel.nu

Hi, 

I run a small food blog in Swedish. I have come across a problem where my search function those not support åäö values. If I for example search for a swedish recipe of "Köttbullar" (meatballs) there will be no search result since the characters are not supported. 

Is there any way to be able to change the underlining code for this? I suppose I would have to use ISO 8859-1 if I am not mistaken? 

I haven't been able to find a way to do this though. Any help is appreciated!

Br, 
EH