Sea Salt Harvesting in San Francisco
Is sea salt harvesting similar to agricultural harvesting?
Sea salt harvesting has a lot in common with harvesting corn or any other agricultural crop. You wouldn’t intuitively think about sea salt the same way you would tomatoes – but there are many parallels, according to Butch, Product Supervisor, at Cargill Salt Newark.
Sea salt begins by bringing sea water into large shallow, interlocking ponds that we call concentrators. Over the course of a couple of seasons we will evaporate the water from these ponds via sun and wind until it is fully concentrated into a brine. From there we will put the brine into crystallizers where the sea salt will precipitate out.
The San Francisco Bay Area has a unique climate—similar to a Mediterranean Climate with defined rainy and windy seasons and moderate temperatures year round. Since Cargill Sea Salt is Made Naturally with Sun, Wind and Time™, our success is largely determined by the weather. San Francisco doesn’t tend to have rain storms in the middle of the summer. The evaporation process via sun and wind is essentially the growing season for sea salt. This summer dryness and afternoon winds really help determine evaporation rates and salt crop volume. Dry windy weather is very good sea salt weather. It is difficult to think of a better environment for sea salt in the United States.
Seasonality plays a huge role in sea salt harvesting in the San Francisco Bay Area. Like in agriculture, sea salt has distinct seasons—a planning season, a growing season, and a harvesting season. “Planning” season signifies the start of the process beginning around late April and May after the winter rains have stopped.
Next, comes the growing season. “Growing” begins when we start seeing positive evaporation; it lasts throughout the summer months of June through August. Most of the hard work is done by the summer sun and the winds. The weather plays an enormous role in our seasonal schedules.
After the growing season comes the harvesting season, between September and December. In a typical year, we hope to harvest about five inches of sea salt. We work to complete the harvesting before San Francisco’s rainy season starts in January. Our weather—particularly the rain—can have a huge impact on sea salt harvesting.
Roughly speaking, for every inch of rain received, a quarter inch of salt is dissolved per acre that we just produced over the summer. We make sure to get the harvesting done before the heavy rain season to minimize the loss in the field. Depending upon the weather, it can take between three and five years for a sea salt crop.
Cargill’s sea salt production is a low energy process. The sea water is evaporated naturally by the sun and wind and transferred from pond to pond largely using gravity and tides. The production process is remarkably simple and similar to how it has been done for hundreds of years. Cargill's Sea Salt Offerings.