"Once pulled from the ground or severed from their mother plants, fruits and vegetables begin their march to their twilight, and there is a narrow window between optimal flavor and appearance and the onset of decay and rot."
Michael Ableman, Street Farm: Growing Food, Jobs, and Hope on the Urban Frontier, 2016
You've spent months germinating seeds and caring for young seedlings. Now your plants are full of produce and you're ready to reap the rewards of your garden. How you handle your newly picked fruits and vegetables will make or break their flavor and appearance. And, should you choose to share your harvest, there are ways to increase the longevity of produce to keep it fresh longer.
Here are 6 tips to get the most from your harvest:
1) Start with good hygiene
Wash your hands and harvest equipment thoroughly. Only use clean, sanitized tools.
2) Quickly remove "field heat"
It's important to understand how fruits & vegetables lose flavor.
Fresh produce respires to produce energy - using stored carbohydrates, proteins and fat - and releases carbon dioxide and heat. 1 As produce loses carbohydrates to the air, it loses flavor. Because crops respire at different rates, the time between harvest and optimal flavor varies:
Cooling slows down the loss of carbohydrate and vitamin loss.
Field heat is the difference between the temperature of the crop harvested and the optimal storage temperature of that product.
Ways to quickly remove "field heat":
a) Avoid harvest during the heat of the day. Crops harvested early in the day have a lower internal temperature.
a) Minimize the delay between harvest and cooling
b) Keep produce in the shade
d) Mist to prevent water loss (water removes heat 5x faster than air)
3) Store at the proper temperature
What temperature should produce be stored? Use the chart below
4) Manage produce that emits ethylene
What is ethylene? This is a gas that is released by certain fruits and vegetables as they ripen. Exposure to this can cause other produce to over ripen or spoil quickly. Do not store ethylene producing fruits and vegetables with your other produce.
Ethylene damage typically does not occur within 24 hours of exposure. 1
Click here for a list of ethylene emitting foods.
Let's talk tomatoes. Tomatoes emit ethylene - which causes them to ripen. Tomatoes should not be refrigerated (unless cut). Set them out on the counter at room temperature out of any sunlight. Wash tomatoes just before use.
To quicken the ripening process, store crops that emit ethylene in a sealed paper bag in a dark place.
5) Reduce water loss
Most fresh produce is 85% to 95% water when harvested - so it is important to retain water in order to retain flavor & appearance.
"Fresh produce continues to lose water after harvest, but unlike in the growing plant, it can no longer replace lost water with water from the soil. Instead it uses up water in the harvested produce. This loss of water from fresh produce after harvest is a serious problem that causes wilting and shriveling as well as loss of weight." 1
Here are some tips to slow water loss:
a) lower the temperature
b) increase the humidity
"Home refrigerators are generally cold and dry (40°F and 50-60% relative humidity). This is fine for long-term storage of garlic and onions, but not much else. Putting vegetables in perforated plastic bags in the refrigerator will provide cold and moist conditions, but only for a moderate amount of time. Unperforated plastic bags often create too much humidity, which leads to condensation and growth of mold or bacteria." 3
c) reduce air movement (the faster air moves around fresh produce, the quicker water is lost)
d) protect with packaging to minimize bruising
Let's talk herbs. Herbs can be stored with cut stems submerged in water and a plastic bag placed over them to increase humidity. Placed in the refrigerator, these will last a few days. Another method is to wrap in a wet paper towel and store in the refrigerator in a sealed plastic bag.
Note that basil should be stored at room temperature, while others like cilantro, mint, parsley and oregano should be refrigerated.
6) Choose when to wash
Let's talk lettuce. Here are some tips from Lenny's Lettuce (Pacifica, CA):
"I harvest lettuce at an "adolescent" stage where it just becomes firm enough and not too big that it folds over on itself. I harvest outer leaves only, leaving 4-6 leaves on the plant at all times to continue growing for months. Then it's washed, dried and refrigerated straight away. Unfortunately, plastic bags work the best for storage but I've eaten salads that were nearly a month old and still enjoyed it."