In Scandinavia one can enjoy lutefisk

In Scandinavia one can enjoy lutefisk, which is unlike almost any other seafood dish. The fish is saturated in a highly alkaline solution of either sodium hydroxide or potassium hydroxide. After being soaked like this for days, the alkaline solution breaks down the protein in the fish and causes it to bloat into a large, jelly-like mass. If left to soak too long, the fats of the fish can even begin to turn into soap. It then needs to be soaked in plain water for about another week so that it is safe to be eaten, as it can cause chemical burns if not treated. The final product, lutefisk, has a pH of up to 12, making it 100,000 times more alkaline than water and highly caustic. Lutefisk is so alkaline that it cannot be eaten with certain types of cutlery. Silverware will corrode, and any plates or cooking pans with residue from lutefisk left on them can become eroded and ruined overnight. Lutefisk can cause severe pain if eaten by anyone with stomach ulcers or similar gastrointestinal problems.