Water is called the “universal solvent” because it dissolves more substances than any other liquid.

Wherever water goes, through the ground or through our bodies, it takes valuable chemicals, minerals, and nutrients along with it, redistributing molecular resources around the planet.

Beyond its environmental and biological functions, water is the single most important ingredient in our food.


The Modern English word for water is ancient and mostly unchanged phonetically, making it a rare etymological specimen.  Modern English water derives directly from this chain: Proto-Indo-European wodr, Proto-Germanic watōr, to Old English waeter.  Interestingly, the Latin root aqua that is used in some romance languages like Spanish (agua) and Italian (aqua) comes from another Proto-Indo-European word, hekeh, which is translated as “flowing water” rather than referring to water itself.

Jellyfish are about 95% water, compared to our ~60%


A mildly humorous way to refer to water is by its unfamiliar chemical name (though improper): dihydrogen monoxide.  In 1983 an April Fool’s Day news article was circulating about this ‘dangerous chemical’, its deadly effects on human health and its corrosive capacity:

The Durand Express, a Michigan weekly, reported alarming news concerning a dangerous chemical that had been found in the city’s water pipes. The chemical was known as dihydrogen monoxide. The paper explained that inhalation of this chemical “nearly always results in death,” and that “vapors from it cause severe blistering of the skin which can be fatal if extensive.” At the end of the article the paper revealed that the chemical formula of this substance was H20 (water).

There is a website devoted to DHMO awareness and regulation still active today, preserving the joke far past its prime in the early 90s, when it was included in spammy chain emails for years.

We all know that water is essential to almost all life on Earth – there are some rare extremophile bacterium that live outside of the planetary water cycle, but for the sake of this blog’s theme, we will stick to the importance of water in our food system.  Over 70% of the fresh water used by humans goes toward agriculture, of which 90% is for crop irrigation.  This includes not only food crops but textile crops like cotton, which as you will learn below, is one of the most water-hungry crops currently grown.

This creative website is a great visualization of just how much water goes into food production.  In the United States, we “consume” the equivalent of 3,496 liters of water per day just from the food that we eat.  This number comes from the amount of water that goes into raising the cow that is now your hamburger, or the total amount of irrigation needed to grow the potato that is your side of fries.  Water accounted for in this way is called virtual water.  When one digs into the data, you begin to realize that the amount of fresh water needed to produce a single food item is mind boggling.  Roughly three pounds of standard CAFO-raised beef (meaning cows eat grain as well as silage) takes 15,400 liters of water to make it to the meat case at your grocery store.  The same amount of wheat takes up to 1,800 liters and, perhaps worst of all, a mere kilogram of coffee takes a whopping 18,900 liters of water to produce!


All of this accounts for 92% of individual water usage – not from drinking plain water, not taking a shower or watering your garden, but simply from eating food.  For further study, the book Your Water Footprint by Stephen Leahy is a fascinating resource loaded with infographics that break down a wide variety of services and goods into water usage statistics.  The Food Scholar does not receive any sort of referral compensation for recommending this book, it is simply a genuinely good resource for exploring a wealth of data on virtual water.

Another factor to consider is not just the amount of virtual water needed to produce a food item, but how much of that item is being produced.  Humans grow so much wheat and rice that together, those two crops alone account for more agricultural water usage than all other food crops combined, while as individual crops they appear to be rather water sparing, at least by finished weight.

When nutrition is taken into consideration, the equation becomes even more complex.  Spinach takes far less water to grow than almonds, but spinach leaves have little nutritional value by weight compared to nuts.  Therefore, the protein grams, fat grams, carbohydrate grams and calorie count produced per liter of water is far higher for almonds than for spinach, making nuts more water efficient when it comes down to value as a food for humans.

Water is intricately woven into our food production system, far beyond watering plants and keeping livestock hydrated.  Pollution and climate change have caused drastic alterations to the way we can use water to feed the planet, creating a new need for clever tactics in sustainability and conservation.


This post is heavy stuff, so to make up for it, here’s a lovely, light and easy recipe for a watermelon agua fresca.  Add a shot of mezcal to this beverage if that helps you feel better about everything you’ve just read.

Watermelon Agua Fresca

A traditional drink sold by street vendors in Mexico.  Substitute practically any juicy fruit in existence for the watermelon with equally refreshing results.

Total Time 25 minutes
Servings 8


  • 4 cups seedless watermelon cubed
  • 1/2 cup agave nectar
  • 1/2 cup water
  • 2 limes one cut into wheels, one juiced
  • 1 cup mezcal (optional)
  • 1 bunch fresh mint separated into sprigs
  • 4 cups ice crushed or cubes


  1. Puree the watermelon and water in a blender until smooth. Add agave nectar, lime juice and mezcal, if using.  Adjust sweetness to taste and pulse blender to combine.  Serve in a highball glass over ice with mint sprigs and lime wheels as garnish.

Recipe Notes

You can strain the agua fresca, if a thinner consistency is desired.