World Water Day 2012

By coincidence, our CSA delivery day this week falls on the UN's World Water Day 2012,

There are 7 billion people to feed on the planet today and another 2 billion are expected to join by 2050. Statistics say that each of us drinks from 2 to 4 litres of water every day, however most of the water we ‘drink’ is embedded in the food we eat: producing 1 kilo of beef for example consumes 15,000 litres of water while 1 kilo of wheat ’drinks up’ 1,500 litres.

When a billion people in the world already live in chronic hunger and water resources are under pressure we cannot pretend the problem is ‘elsewhere’. Coping with population growth and ensuring access to nutritious food to everyone call for a series of actions we can all help with: follow a healthier, sustainable diet; consume less water-intensive products; reduce the scandalous food wastage: 30% of the food produced worldwide is never eaten and the water used to produce it is definitively lost! produce more food, of better quality, with less water.

As citizens of an arid basin surrounded by mountains on one side and the Pacific ocean on another, most of our region's food and fresh water is imported over high mountain passes.  Ironically, less energy may be required to truck vegetables from the Central Valley over the El Tejon pass aka "The Grapevine" (4160') than to grow vegetables locally inside our basin with water imported via aquaducts reaching ~750'?

Why?  Because water is heavy and crops need water nearly continuously throughout their growing cycle.

Worry not about what your CSA box does to your annual carbon budget.  Farmer Tanaka employs ultra-efficient drip irrigation, often in conjunction with plastic row covers that minimize evaporative losses from the soil, AND he uses reclaimed water from the Irvine Ranch Water District.

On my farm here in Irvine we use a drip irrigation system on our crops that puts the water right in the root zone  so as to use our precious water as efficiently as possible with no runoff. We also use reclaimed water supplied by the IRWD (Irvine Ranch Water District) who produces the cleanest and safest reclaimed water in the country.

Using reclaimed water gives the added benefit of not adding salts to his soil. Gardeners in this region may be familiar with the heavy load of salts in our "hard" water. If we irrigate regularly with hard water and the water evaporates or is taken up by the plants, you may notice a white powdery substance left behind. That's the salt building up in the soil.  (Even if you are not a gardener, you can see the white calcium salt deposits in your kitchen and bathroom.)

If the winter rains do not come to flush the salts away, gardeners and farmers need to deep water (often repeatedly) the land to flush the salts away artificially.  This is very water intensive.

The reclaimed water is so pure, it doesn't have the salts found in freshly-imported river water.  Thus, Farmer Tanaka can drip irrigate just the amount needed by his plants, without worrying about poisoning his fields with salt.

What does that mean for your CSA food?  It may have a lower carbon and water footprint than even food you grow in your own backyard*.

* Residents of north Redondo Beach get about half our water supply from local aquifers, which are replenished with reclaimed water from West Basin Water District's Edward C. Little Water Recycling Facility in El Segundo, California.  Read a report about a visit to the facility.  You can also learn more in walking my watershed.

Unfortunately, pumping the water into the ground and then pumping it back up uses energy and loads the water up with salts.  I'd much rather use the cleaner reclaimed water directly from the plant, but the general public is still resistant due to the "eww" factor. I hope you will be a vector for getting the truth out.

The Science of Cooking

The Harvard Series on Science of Cooking lectures are now available online.
Visit the lecture series website for links to the series on both iTunes U and YouTube.

Who knew that the pressure cooker is a spinoff from Boyle's experiments with vacuum?  Although, I guess it shouldn't have been too much of a surprise. 

No more soggy cilantro

Cilantro, like many cut plants, wilts over time.  The cure for this is to trim the cut ends and plunge them into a vase of water.  Use enough water to cover most of the stem, but not the leaves.

 Then place a loose plastic bag over the cilantro and put it in the refrigerator.

When you want to use a bit of cilantro, just take out the small amount that you need and put the rest back in the refrigerator.  Cilantro can stay fresh over 2 weeks in the refrigerator this way.

Celery also benefits from this treatment.

To the CSA box celery, we added some carrot flowers from our garden and a stalk of artichoke from Trader Joe's to make an edible bouquet.

Most people don't eat the carrot tops that come with the CSA carrots, but they are really pretty when put in a vase with some flowers from the garden or store.

You can use a glass instead of a vase, but a vase has a more stable base.  You can also put it in a plastic juice pitcher, but then we don't see the cilantro and forget about it.  Oops.

The science behind this:
When you trim (1/2" to 1") off the ends of the cilantro, you open up the small tubes that draw water from the bottom of the plant to the leaves.  It's lack of water up at the leaves (not an excess of it) that makes the leaves wilt.

If you place the vase of cilantro out at room temperature, you can watch the water in the vase disappear through evapotranspiration out through the leaves. 

How does the speed of the evapotranspiration vary with the temperature in the room?  The humidity?  The level of water?

The water in the vase can also breed bacteria.  After you are done with this experiment, rinse the cilantro and vase to reduce the bacteria, refill the vase, and put the cilantro back into the vase.  You may want to trim about 1/2" off the stems again.

If you don't use the plastic bag, the cilantro will evapotranspirate water into the refrigerator, which is not good for some of the other food in there.  That's why you want to use the bag.