We are continuing with our series on storing and preserving your harvest. First up is cold storage. This method has been practiced as long as we have had agriculture. It is easy and fast. Traditionally folks used root cellars and cold rooms, but most of us don't have those anymore. No worries, we can use modern conveniences like refrigerators and unheated garages.
This method is perfect for long term storage of all our root vegetables as well as many of our brassicas and our pomme fruits. Plus, we can also use this technique to store our produce until we are ready to process them in other ways such as canning or freezing. Remember to only store pristine produce. Any damage spots due to physical injury, insects, or disease will provide an entrance point for rot and mold to ruin our produce. Eat these guys first and save the perfect specimens for longer term storage. Also, a quick note about washing: don't do it yet. Washing our produce before cold storage will result in too much moisture and can result in physical damage to the skin or peel of our veggies and fruit. All we want to do is lightly brush off any dried soil and remove the stems and leaves for our root veggies.
There are two main types of cold storage: cold and moist or cool and dry.
Cold & Moist Storage
Cold means as cold as we can get without freezing, so around 0 to 5°C, and moist means a very high humidity of 95 to 100%. This is the environment that all root vegetables appreciate. These include carrots, beets, celeriac, kohlrabi, parsnip, potato, rutabaga, and turnip. Our cruciferous vegetables, like Brussel sprouts and cabbage, also do well stored this way. Leeks, our oddball allium, is the final vegetable to store with this method.
The key thing to think about with cold and moist storage is dealing with excess moisture. Not only do we have a humid environment, our vegetables themselves can give off moisture over time. We want to ensure there is never any liquid directly touching our veggies. That leads to the dreaded bad guys of rot and mold. That means we need some sort of absorptive material in with our vegetables.
If we are storing smaller amounts, or smaller sized vegetables, our refrigerators are perfect. They are cold and humid, just like we want. Plastic bags or containers work well to package them in (I like to recycle bread bags for this purpose). For absorption of excess moisture, paper towels are ideal. Just throw one or two of them in the bottom of each bag and seal with a clip or twist tie. That's it! Makes you think about getting an extra refrigerator so you can grow more carrots, doesn't it?
For larger amounts, we need a larger environment. An unheated garage usually works well. Large plastic storage totes (Rubbermaid is one popular brand) will allow you to store an entire winters worth of your favourite veggie, but you can also use barrels or large crocks. Bulk material such as sawdust, fine wood chips or sand work as our absorptive material here. (Pet stores and the UFA are good places to find these products cheaply.) We want to layer about 2" of this material in the bottom of our container. Follow this by a single layer (no overlapping!) of our veggies, then a 1" layer of sawdust (or your desired material). Repeat until you fill the container. End with a 2" layer of your sawdust and a lid. This 2" layer of material around the entire outside of the container not only helps with soaking up excess moisture, it also acts as insulation to prevent freezing. Frozen produce equals mushy produce once it thaws. All you need to do is reach in and grab a couple turnips or potatoes whenever you are ready to eat!
Cool & Dry Storage
The second method of cold storage is a little bit warmer and a whole lot drier. We are looking for a temperature of 10 to 15°C. A cool basement room, especially on an outside foundation wall is one place to check out. Basically, find the coldest room in your house and use that. We also want dry, about 50 - 70% humidity. Thankfully for those of us in the prairie provinces, this is close to the humidity in our homes in the winter months. All of our winter squashes, pumpkins, pomme fruits (apples and pears) and the onion family (with leeks being that weird exception) enjoy this environment.
The key for cool and dry storage is keeping our produce dry, and that means really good air circulation. Refrigerators, bags and containers will not work here. Large produce can be kept on shelves with slats or holes (see photo above) and smaller produce works great mesh bags. Our alliums such as onions, shallots and garlic are great with their stems braided together and then hung. In order to make our produce last as long as possible, some of them benefit from curing before being put into long term storage.
For both of these storage methods, it may not be possible to get the exact perfect conditions we are going for. I have suggested some pretty specific temperature and humidity ranges. Honestly, most people are not measuring their humidity. That's okay. Get as close as you can and consistently as you can. If its not perfect, it just means you produce won't store quite as long. And that may be okay for what you need.
How To Cure
Curing is the process of allowing your produce to fully dry and the skin to harden. This helps your vegetables store for as long as possible. There is actually not a ton of difference between the curing environment and long term storage. The only real difference is temperature. To cure, we want warm and dry instead of cool and dry.
Begin by brushing off as much dirt as possible, while still being gentle. We don't want to damage that skin or those outer papery layers. Next, we need a warm location of 20˚C or higher. If it is a really nice warm fall, outside may be an option. If there is any rain in the forecast, bring them inside. Your pantry will work just fine. Once again, air circulation is key to keeping everything dry. If you have lots of produce a fan is not unheard of. All alliums store longer when cured (except leeks again) and need around 2 - 3 weeks of curing before being moved to long term storage. You can tell they are ready when the stems are fully dried all the way through. Try bending them and taking a peak. Only some winter squashes need curing. These include butternut, buttercup, kabocha, Hubbard squash and edible pumpkins. Acorn, spaghetti, delicata and sweet dumpling squashes don’t need require curing before storage. Ensure they are fully ripe first and leave about 1” of stem attached when harvesting. Cure these until the rinds are hardened, between 1 and 2 months. You shouldn't be able to pierce them with your thumbnail when they are fully cured.
That's not too involved, is it? Fairly simple, no equipment required and very little actual work on our part. All things that make cold storage a fantastic way to store our summer produce. Up next, we are going to explore all the ways we can store our produce in the freezer!
Yummy gardening everyone!