Help! My Greens Are Brown!

We have had a lot of questions over the last couple weeks about why the greens have been turning brown more quickly in the summer than in the winter. The short answer is heat.

Greens are out in a field under the hot sun until they’re picked. Once picked, a large commercial farm will immediately run the greens through either a hydro cooler, vacuum cooler, or a pressure cooler. Hydro coolers run produce through an icy cold bath and are commonly used for avocados and other stone fruits. This method isn’t great since it can leave you with water soaked and transparent leaves that have to be trimmed off. Vacuum coolers are perfect for greens, but can take more than five years for a high volume farm to pay off.

A pressure cooler is created by using a fork lift to place stacks of produce pallets in two rows on either of a large cooler fan. The pallets create a tunnel and are covered by a tarp to force the air from the fan through the tunnel. The pressurized cold air leaches any remaining sun heat out of the plants and temporarily stops the breakdown of the plants’ cells.

Small local farms don’t usually have access to these types of advanced and expensive cooling systems. They are a serious investment for such a low profit market and require a lot of open space to use that most small farms can’t really spare. Small farms usually use walk-in style coolers, which take a bit longer to remove the same amount of heat as the other types of coolers.

The time of day they are harvested impacts the amount of heat that is carried into the cooler. A one acre field of romaine lettuce harvested in the morning contains about the same amount of heat as 1/4th of an acre field harvested in the early afternoon. Another factor is how fast the greens are placed in the cooler after being picked. The longer the greens have to wait before going into the cooler, the less shelf life they will have.

Knowing the shelf life of your greens can help you plan which greens to use first when planning meals throughout the week. According to the Canadian Produce Marketing Association (CPMA), lettuce variety greens, like romaine, green & red leaf, or spinach, only last about one week in refrigerated storage. It is recommended to wash them before storing. Other varieties of greens, like collards, kale, and chard, only last between 2 – 4 days refrigerated before they start to develop spotting and it is recommended that you do not wash them before storing. So use the chard or kale right away and save the lettuce for later in the week.

There is also a great technique from Discovery Organics for extending the life of your greens that you can do right away. Immediately remove any brown or over-saturated leaves and trim the stem, so that it is freshly cut. Then, immerse the lettuce in bath temperature water for about one minute. Immediately immerse the lettuce into icy water following the warm water and leave for 2-3 minutes. Plants are made up of cells, just like we are, so this technique works similar to washing your face. The warm water opens all the pores on the leaves and allows them to suck in water. The cold water is quickly absorbed and causes the pores to seal in all that fresh cold water. Just make sure to dry any excess water off of your kales and chards before sticking them into the fridge.

Our newsletter is written for you, so feel free to let us know what interests you! I’m always happy to write articles regarding questions you might have or topics you’re interested in. ~ Rachel

Prolonging Your Produce

How many times have we set something on a shelf in the fridge or placed it inside the crisper, only to come back not even two days later to find it has gone bad? Thankfully, prolonging the life of your organic produce is not as hard as you’d think. It all starts from the moment it enters your home.

The cleaner your produce is before it enters your fridge, the longer it will last. As a side note, the cleaner your fridge is, the longer your food will last as well. Gently wash and dry all produce before storing it, even those with protective skins on them like oranges and bananas.

 I recommend using a solution of 3 parts water to 1 part vinegar, the vinegar works as an anti-bacterial and keeps the produce from breaking down as quickly. For an even more complete clean, try adding a tablespoon of baking soda and a squeeze or two of lemon juice.

The baking soda and vinegar will react together, helping to actively clean the produce by forming bubbles of hydrogen dioxide. The lemon acts as an astringent, helping to close the pores of the exposed plant tissue and prevent access to invading bacteria.

Once washed, spread your produce on a flat surface and separate all your leafy greens from everything else. Interesting fact, if you put spinach or kale in the same bin as apples or peaches, the greens will become yellow and limp within a day or two.

The reason for this is differences in production and reactions to Ethylene gas. By keeping your leafy vegetables separate, you are actually prolonging their life in your fridge.

On to storage! Keep the locations that you store you produce dry. Some people prefer to wrap each leafy vegetable in paper towels until they are ready to be used. This is a good method and helps to absorb the water, keep the leaves cooler, while still letting them breathe.

Another greener alternative is to invest in some new produce dedicated dishtowels. Wash the dishtowels in the same vinegar/baking soda/lemon solution as I mentioned earlier, rinse well and let them air dry.

Line the bottom of each bin with a dish towel and then, once the greens have been placed in the bin, place another dry dishtowel on top. You can layer additional towels as needed. By using dishtowels, you can easily switch out a damp towel for a dry one and lower your paper usage footprint.

If you are interested in finding out the optimum temperatures and storage for a specific type of produce or knowing more about which types of produce are sensitive to Ethylene (like Avocados and Carrots), please check out this produce storage table.