Hawaiian sea salt is popular for traditional Hawaiian dishes ranging from poke to lau lau pork. The red variety brings an earthy nuttiness as a result of its mineral content. You will need Hawaiian sea salt if you want to make Hawaiian dishes that have traditional flavor profiles. If you cannot find Hawaiian sea salt or simply do not have the time to go looking for it, consider one of the Hawaiian sea salt substitutes below.
Your best bet: Pink Himalayan salt
As the name suggests, pink Himalayan salt is mined in the Himalayas and has a pink or reddish color that comes from its mineral content in much the same way that the color of red Hawaiian sea salt comes from its mineral content. Himalayan sea salt is actually the residue from a dried up inland ocean trapped by tectonic shifts. Its color and the subtle mineral flavor is what makes it the best substitute for red Hawaiian sea salt. Another factor that pink Himalayan salt has in common with Hawaiian sea salt is that it works well as a finishing salt, especially if you use a coarser grind. Pink Himalayan salt will provide a similar appearance in addition to the crunchy texture that you want from large salt crystals.
Use pink Himalayan salt as a 1:1 substitute for any of the Hawaiian salts, but its color makes it particularly most effective as an alternative to red Hawaiian sea salt.
A decent second choice: Kala namak
Kala namak is also known as Indian black salt and is a great option if you are seeking an alternative to the black lava variety of Hawaiian sea salt. Black Hawaiian salt does not occur naturally; rather, it is a man-made product made by combining sea salt with activated charcoal. The result is a salt with earthy, sulfurous flavor notes. Kala namak is man-made and is formulated by combining sodium with charcoal and a variety of Indian spices to create a blend that has similar sulfur notes as those provided by black Hawaiian salt. It is often used as an egg substitute in Indian vegetarian dishes.
Kala namak has a stronger flavor than black Hawaiian sea salt. Start by adding half the amount that your recipe requires for black Hawaiian sea salt and increase to taste.
In a pinch: Fleur de sel
Fleur de sel is a French sea salt that is known for providing a clean, briny flavor. It is gently skimmed from the surfaces of tidal pools in Brittany. It is a light gray salt without the striking color that makes red Hawaiian salt useful for enhancing the appearance of food; however, it does provide a deep oceanic saltiness. The crystals are also large and can provide a crunch.
You can use fleur de sel as a 1:1 substitute for any of the Hawaiian sea salt varieties, but it will work best in place of white Hawaiian sea salt.
Kosher salt does not have the mineral flavor notes that you would get from Hawaiian sea salt; however, it does have the large crystals. Kosher salt crystals will last for longer on the surface of foods without dissolving and can add a crunchy texture.