What Temperature Should a Root Cellar Be? (How Cold?)

Root cellars are designed to store food at a cold temperature in order to preserve them for weeks or months. Rather than letting them sit on a shelf and rot or take up space in your refrigerator, you can use a root cellar to keep your fruits, vegetables, and other organic food safe for extended time periods.

Most experts suggest that you should keep your root cellar between 32°F to 40°F (0°C to 4°C), which happens to be the same recommended temperature range as a refrigerator. Depending on the food inside, you can adjust it to be colder or warmer.

Throughout this article, you’ll learn the following information about root cellars:

• What temperature should they be for fruits and vegetables?
• Can you change the temperature in a root cellar at various spots?
• Additional storage suggestions

What Temperature Should a Root Cellar Be for Fruits and Vegetables?

When you’re storing fruits and vegetables in a root cellar, a slight temperature variation can extend or reduce the amount of time that they’re good for. For example, if you go too far over 40 degrees, you could risk spoiling them much quicker. On the other hand, storing certain fruits and vegetables below 32 degrees could freeze them and ruin the flavor.

As mentioned above, you should have your root cellar set between 32 to 40 degrees F. This temperature range sits right above freezing, making it a perfect setting for fruits and vegetables. You won’t have to worry about bacteria thriving, nor will you have to thaw your produce before you eat them.

Humidity is equally as important as temperature. If your cellar is too dry, it could remove the moisture from your food. On the other hand, too much humidity can invite bacteria to start to grow. It can also cause ice crystals, changing the flavor of the food. Natural evaporation calls for additional humidity to be controlled and added.

The interior humidity of your root cellar should be between 85 to 95 percent to keep them preserved for weeks or months. You’ll be able to eat them without the worry of bugs, bacteria, and other harmful critters.

Another reason that the humidity range and cold temperature are both necessary is that they slow the decomposition process. They combine to reduce the amount of ethylene gas that’s produced, which usually causes microorganisms to eat away and decompose food.

Contrary to popular belief, you can have a root cellar in a variety of locations. Here are a few examples:

• Garages
• Garbage bins
• Basements
• Manmade cellars underground
• Holes in the ground

Anywhere that you can block excess light while controlling temperature and humidity will make a great root cellar. From there, you can gauge the settings to preserve fruits, vegetables, jarred foods, and more.

To learn more about how deep root cellars need to be, check out my article called How Deep Does a Root Cellar Need to Be? | A Simple Guide.

How Do You Adjust a Root Cellar’s Temperature?

If you’re lucky enough to have a thermostat in your root cellar, you can turn it up or down to fit your desired temperature range. You’ll also need something to add humidity, so feel free to add a hygrometer, like this one, if you don’t have one. Some climates fit the required humidity range as is, in which case, you won’t have to adjust much at all.

There are numerous other ways to adjust the temperature in your root cellar. If you’re trying to figure out how to have multiple temperature readings for different kinds of food in a single cellar, it can be a bit tricky. Here are a few suggestions that you could try:

• Dig a hole about 10 feet deep to maintain the temperature of your liking. At this depth, you can control the temperature without the outside ambient temperature outside adjusting it for you.
• Maintain proper air circulation by keeping all of your food about two to three inches away from walls, floors, ceilings, and other objects; Otherwise, mold can start to grow.
• Consider building a wall between your root cellar to divide it into two different areas. This will allow you to install an additional thermostat to adjust it to the needs of different kinds of food.
• If you’re using central cooling, keep your food that needs a lower temperature closer to the vents. Most cooling vents go as low as 20 degrees less than the set temperature in order to combat the stagnant air in the room. You can leave food that doesn’t need to be as cold a little bit further away from the vents.
• Add an exhaust pipe to remove heat from the earth and running machines (humidifiers, thermostats, vents, hygrometers, etc.). Place the exhaust pipes closest to root vegetables and other foods that don’t need to be as cold as others.

As far as controlling the temperature in a single, unseparated root cellar, it’d be quite challenging. Other than proper vent and exhaust pipe placement, there’s not much you can do other than separating them. If you’re truly concerned, try to jar some of the food to keep it separated.

Additional Storage Tips for Root Cellars

Maintaining a root cellar is very simple once you get everything started. The hardest part is controlling the environment, but you can easily do it with the proper tools. If you’re trying to figure out how to keep the temperature where it needs to be, try these five helpful storage suggestions:

1. Never try to make a root cellar in a shed or any other area where you can’t completely adjust the temperature and humidity. If you only have a shed to use, insulate it as much as possible. The wood and metal that most sheds are made out of are awful for insulation and temperature control, not to mention they can corrode and rust.
2. Don’t short yourself on the humidifier and cooling system. They’re both very crucial to the effectiveness and longevity of your root cellar. You should predict that the biggest portion of your cellar’s maintenance will go towards repairs for those parts more than anything else, though they don’t need to be fixed often.
3. Dirt is an incredible insulator. If you’re able to do it, make your root cellar underground. Dirt has been used to build houses and huts for centuries, so why not use it as an inexpensive way to control the temperature and humidity of your root cellar?
4. Consider adding fans inside of your root cellar to circulate the cool air. You can use this technique to reduce the temperature of specific spots over others, although it’s not as effective as a separate room.
5. Be mindful of the types of lights that you use in your cellar, if any are present. Some lights, including incandescent bulbs, get very hot quickly. You can end up overheating your food that rests directly underneath the lights. Instead, try to carry a lantern or a flashlight whenever you go inside.

Conclusion

Root cellars need to maintain a stagnant cold temperature and humidity in order to preserve everything inside of it. Once you have your cellar set up and ready to go, you’ll be able to control the environment with very little effort or money.

Here are a few takeaways from the post:

• A root cellar should be between 32 to 40 degrees Fahrenheit.
• Vents, pipes, and fans can be used to adjust the internal temperature.
• You need top-notch insulation to prevent external ambient temperature from changing the root cellar’s environment.
• Consider separating your root cellar into small rooms or closed shelves to house multiple temperatures.

Recommended Root Cellar Maintenence Products

I took the time to list some things you might need for a root cellar. Here are a few Amazon products that you may find helpful:

• Hygrometer– For measuring temperature and humidity.
• 5-Gallon Gasket Sealed Plastic Buckets– The perfect size for my long-term storage needs.
• 5-Gallon Mylar Storage Bags– Fill these bags, seal them, then put them in the bucket for ultra-long-term storage.
• Root Cellar Storage Bins– For storing most veggies.
• Airtight Storage Containers– For short or mid-term use.
• Storage Labels– Logging the date and contents is important.

For more, don’t miss What Is a Root Cellar? Why They Work & What They Are Used For.