Cooking With Sea or Salt Water

If you’re already a commuter cruiser, you probably know that salt water is much more dense than fresh water.  I can literally swim for hours with almost no effort in salt water, but put me in fresh water and I sink like a rock!  Just treading water is an effort in fresh water.

If you’re cruising without a watermaker and want to use sea water to cook, or if you’re like us and have a watermaker but are just curious, here are a few tips:

1.  Make sure the saltwater you’re in is clean – despite the fact that boiling the water will kill anything lurking, I cannot imagine using the water in a lot of the anchorages we’ve been in to cook!  Especially in US waters, unless you happen to be anchored in the Keys far away from civilization … the only place I can think of offhand would be the Dry Tortugas.  David won’t even run our watermaker in most of the anchorages along Florida for fear of gunking up our filters.

Belizean Waters (above) and Panamanian Waters Were Sometimes Clean

Belizean Waters (above) and Panamanian Waters Were Sometimes Clean

2.  Because salt water is denser than fresh water, it has a slightly higher boiling point.  Fresh water will boil at 212 degrees, salt water boils at 217 degrees.  That five degrees doesn’t seem like much, but it will cause some differences in cooking.

3. Salt water will take slightly longer to boil because of it’s higher boiling point.

4.  Salt water/seawater has a much higher concentration of salt, approximately 3.5%, than what you would typically add to water while cooking … pasta for example.  So if you’re using seawater to cook to save freshwater, just keep in mind, that for every gallon you use, there’s approximately 1/2 cup of sea salt in it.  And now that we’re watching sodium even though neither of us have high blood pressure, it just seems like a good idea, we wouldn’t begin to cook with salt water.

5.  When salt water does boil, because it’s at a higher temperature, whatever you’re cooking will cook somewhat quicker than it would if you were cooking it in fresh water.  I haven’t noticed a big difference, but just to be safe,  if a recipe calls for boiling or steaming something for 10 minutes, check it earlier – I like to check after half the recommended cooking time and then every couple of minutes thereafter.  But don’t expect to save a lot of time cooking.

Seawater Is 3.5% salt ... or approx 1/2 Cup Per Gallon

Seawater Is 3.5% salt ... or approx 1/2 Cup Per Gallon

6.  Do not use salt water to cook dried beans.  During the cooking process, salt makes the bean’s skin tough – that’s the same reason you don’t add anything with salt (like ham) to beans until the beans are well on their way to being cooked.

7.  If you’re using seawater to boil pasta or potatoes or anything for flavoring purposes, refer to point #4 above.   It could come out with much more “flavor” than I’d like and I’m a salt-o-holic!   I’ve seen recommendations to use 1/3 seawater to 2/3 fresh water, but haven’t tried it myself.

Just a final thought … if you’re seriously trying to save water by cooking with seawater, consider washing dishes in seawater instead.  It generally takes MUCH more water to wash the dishes than to cook.  Before we had the watermaker, I had a salt water foot pump into my sink.  I always washed dishes in salt water and then rinsed in a bit of fresh water.  Some cruisers use a spray bottle for the fresh water rinse, although I never went to that extreme.

And … jumping in for a salt water bath and just doing a final rinse in fresh water helps too.  That said, we used to both take a shower with water left over in a 2 1/2 gallon solar shower.  Of course, we have short hair.



Consider Washing Dishes in Sea Water if You Need to Save Fresh Water

Consider Washing Dishes in Sea Water if You Need to Save Fresh Water

If you decide to cook with seawater … Buena Suerte!!!

If anyone has more experience than I cooking with seawater, please leave a comment and share!  THANKS!  J



  1. If you drink seawater you will go mad, won’t sea water soup be the same thing?

  2. Rafael Breban says:

    This is my dream, I hope one day I can retire and travel the world. With my current job I won’t be able to do it, but who knows maybe I’ll get the money to start my own business and one day retire. Thank you for the article it was very informative.

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