The first day of fall has arrived, which means vegetable farmers are preparing to save any of the season’s current bounty we want to store for the winter. Here at Glynwood, winter crop storage is an area in which we have gained knowledge over the last few years as we continue our winter CSA. We can even store vegetables harvested in October to distribute at the beginning of next year’s CSA with minimal loss in quality. Here are some of the secrets to our success and some tips for how you can apply them to storing veggies in your own home:
Vegetables must stay alive to remain edible. The cells in vegetables continue to be active (respirate) after they have been harvested and lose moisture to the air (transpirate), but without roots to provide nutrients and water, they will eventually wilt and die. The key to lengthening the shelf life of vegetables is to limit the amount of cell respiration and transpiration occurring in the plant. Colder temperatures slow cell respiration and high humidity prevents transpiration. By regulating ambient temperature and humidity vegetables will store much longer than they would naturally.
For most of our long term storage crops we try to keep our cooler at 33-34℉ with 90% humidity. Keeping the cooler at 90% humidity is difficult so we store produce in plastic bags to retain more humidity. However, too much moisture does cause rotting, and an exciting discovery for the vegetable team last year was finding plastic bags with the perfect number of ventilation holes to keep produce moist -- but not too moist. This works for two months or longer with carrots, beets, turnips, parsnips, celeriac, cabbage, radicchio, celery, leeks, rutabaga, kohlrabi and radishes. Certain varieties of these crops also last longer, so we have increased storage length over the years by finding the right varieties like Bolero carrots and Passat cabbage.
Other storage crops have their own natural method of limiting cell respiration and transpiration by forming a protective outer layer. Onions, garlic, winter squash, potatoes and sweet potatoes all come with their own built in storage ability. For these crops our main strategy is to help them form the best protective layer they can by providing good conditions for their skins to naturally “cure”. Keeping them in the hot and dry conditions of our greenhouse for two weeks works well for curing, although potatoes will just cure underground. Once these crops have cured they all have somewhat distinct temperature and humidity requirements for maximum storage e.g. cold and dry for onions, and warm and humid for sweet potatoes. Our one continuing challenge is finding enough climate controlled spaces to store all of these crops separately.
We are happy to keep vegetables fresh here at Glynwood for our winter customers, but it’s also possible to store produce for long periods in your own home. Tricks like keeping produce in (non-airtight) plastic bags with a moist paper towel or even just using the fridge crisper drawer well can help keep produce for weeks.
For more home storage tips check out this ‘zine and series of veggie cards brought to you by the Hudson Valley CSA Coalition.
And click here to register for our upcoming “Farm with your Farmer” volunteer days, where you can help the Glynwood vegetable team and learn even more veggie facts.