Sweet potatoes are a delicious and nutritious food that can be prepared in many ways. However, there is some debate around whether or not they should be stored in the refrigerator. Here is a comprehensive look at why sweet potatoes should not be refrigerated.
What happens when you refrigerate sweet potatoes?
When sweet potatoes are stored at colder temperatures, this causes the starch to convert to sugar more rapidly. The colder temperature speeds up the starch-to-sugar conversion process. This can result in a much sweeter taste, which some people may enjoy. However, it also means the tubers lose their natural sweet potato flavor.
Additionally, refrigerating sweet potatoes causes the texture to become soft and soggy. The cold breaks down the cell structure of the vegetable. This makes them less pleasant to cook with, as they will fall apart more easily when baked or fried. The change in texture also results in a less smooth pureed sweet potato dish.
Why you should not refrigerate sweet potatoes
There are a few key reasons why refrigeration harms sweet potatoes:
- Flavor – The flavor significantly changes, losing the earthy, nutty taste of a sweet potato. The cold converts more starch to sugar, resulting in an overly sweet flavor.
- Texture – The texture becomes soft and soggy. Sweet potatoes can fall apart more easily when cooked after refrigeration.
- Storage life – Refrigeration can actually shorten the storage life of sweet potatoes by a few weeks compared to storing them in a cool, dark place.
- Nutrition – Some studies have found up to 80% loss in vitamin C and vitamin A antioxidant levels after just a week of refrigeration.
Let’s explore each of these reasons in more detail:
Refrigeration alters the flavor
One of the biggest problems with refrigerating sweet potatoes is the change in flavor. When stored in cold temperatures, more of the starch converts to sugar. This makes them much sweeter compared to their normal earthy and nutty taste when kept at room temperature. For many cooks and consumers, this overly sweet flavor is undesirable.
The optimal storage temperature to preserve sweet potato flavor is between 55-60°F, which is cooler than room temperature but significantly warmer than refrigerator temperature. Storing them around 60°F will keep the flavor intact without excess sweetening occurring.
The texture becomes less pleasant
In addition to the flavor changing with refrigerator storage, the texture is also negatively impacted. As the starch begins converting to sugar, the cell structure within the vegetable breaks down. This leads to a soft, almost soggy texture.
When you try to cook sweet potatoes after refrigerating them, they are more likely to fall apart. They will become mushy more quickly and have a mealy texture. This makes them less ideal for baking whole or frying into wedges or chips.
Pureed sweet potato dishes can also be impacted, coming out thinner and more watery instead of creamy. Leaving sweet potatoes whole at a stable room temperature preserves the intact cell structure and prevents this undesirable texture change.
It can shorten the storage life
Surprisingly, refrigeration can actually shorten the shelf life of sweet potatoes compared to proper cool room storage. When kept between 55-60°F in a dark, well-ventilated area, they can last 3-5 weeks. On the other hand, refrigerator storage may only extend their life to 1-2 weeks.
The increased humidity levels in the refrigerator encourage faster sprouting and mold growth. Ventilated room temperature storage slows this process. The cold temperature also hastens the breakdown of cell walls and conversion of starches to sugars, accelerating the spoilage process.
Nutrient levels decrease
Sweet potatoes are packed with beneficial vitamins and antioxidants, like vitamin C and vitamin A. However, several studies have shown these nutrient levels rapidly decline when sweet potatoes are refrigerated.
One study published in the Journal of Food Science found that refrigerating sweet potatoes for just 7 days resulted in an 80% decrease in vitamin C and a nearly 80% loss in vitamin A antioxidant activity.
Keeping sweet potatoes at stable room temperatures around 55-60°F can help slow this nutrient loss, retaining more of the vitamins so you get the most nutritional benefit.
Proper sweet potato storage
Since refrigerator storage has clear downsides for sweet potato quality and nutrition, the ideal method is to store them in a cool, dark place. Here are some tips for optimal storage:
- Keep them in a well-ventilated area at 55-60°F. The temperature should remain as stable as possible.
- High humidity helps prevent shriveling and moisture loss, so store them in a bin or basket with ventilation holes.
- Avoid direct light exposure, which can encourage sprouting.
- Sort through the tubers every 1-2 weeks and remove any that are sprouting or molding.
- Consume within 3-5 weeks for best quality and flavor.
With proper room temperature storage, you can enjoy delicious, nutritious sweet potatoes for weeks without the drawbacks of refrigeration altering the taste and texture.
How cold affects sweet potatoes
To understand why refrigeration harms sweet potatoes, it helps to look at what happens when they are exposed to colder and colder temperatures:
Above 55°F
In temperatures above 55°F, sweet potatoes begin to sprout and mold more quickly. The higher temperature speeds up cellular respiration. This leads to faster sprout development, shortening the storage life.
50-55°F
Between 50-55°F, sweet potatoes experience minimal changes in texture and flavor over several weeks of storage. This is the ideal temperature range for storage without refrigeration.
40-50°F
From 40-50°F, the starch in sweet potatoes starts converting to sugar at a faster rate, causing the flavor to become noticeably sweeter.
32-40°F
Once temperatures dip below 40°F, the sweetening effect accelerates due to higher starch conversion. The texture also starts becoming slightly soft.
Below 32°F
Below freezing temperatures damage the cell structure of sweet potatoes irreversibly. The vegetable will become mushy and waterlogged in texture with very high sugar content after thawing.
As you can see, colder and colder storage temperatures progressively damage sweet potatoes, changing the flavor, texture, and nutrition. Aim to keep them between 50-60°F for optimal quality.
How long do sweet potatoes last without refrigeration?
With proper storage, cured sweet potatoes will last approximately:
- 1 week at 65°F
- 2-3 weeks at 60°F
- 3-5 weeks at 55°F
The ideal temperature range for storage is 55-60°F. At these cooler room temperatures, sweet potatoes will keep for 3-5 weeks before quality loss occurs. Temperatures closer to 65°F will shorten shelf life to just 1 week.
Make sure to check your stored sweet potatoes periodically for any sprouts, wrinkling, or mold. Remove any tubers showing signs of spoilage promptly to prevent it spreading.
Can you freeze sweet potatoes?
Freezing is not recommended for whole, raw sweet potatoes. The frozen produce will become mushy and watery when thawed. However, you can freeze cooked sweet potato dishes.
To freeze cooked sweet potatoes:
- Cook sweet potatoes until very soft and puree or mash.
- Allow puree to cool completely, then portion into freezer bags or containers.
- Remove as much air as possible and seal tightly.
- Freeze for up to 10 months.
- Thaw in refrigerator before reheating or using in recipes.
With this method, you can enjoy delicious sweet potato recipes for months after harvesting or purchasing them.
Frequently asked questions
Why do sweet potatoes get sweeter in the fridge?
Sweet potatoes get sweeter when refrigerated because the cold temperatures accelerate the conversion of starch to sugar inside the tubers. The fridge humidity also draws out more sugars to the surface.
Can you freeze raw sweet potatoes?
It is not recommended to freeze raw sweet potatoes. The frozen raw vegetable will turn mushy and waterlogged when thawed. Cooked sweet potato dishes freeze well.
Do sweet potatoes go bad if not refrigerated?
No, leaving sweet potatoes at room temperature does not make them go bad faster. In fact, cool room storage between 55-60°F extends the shelf life for 3-5 weeks, longer than refrigeration.
How can you keep sweet potatoes fresh longer?
Choose small-to-medium sized tubers which have less moisture content. Cure them for 7-10 days in a warm, humid area first. Store cured sweet potatoes in a dark, well-ventilated location at 55-60°F.
What happens if a sweet potato goes bad?
A rotten sweet potato will become very soft and mushy in texture. Mold growth, wrinkles, and sprouts are also signs they have gone bad. Discard any tubers showing these signs of spoilage.
The bottom line
Refrigerating sweet potatoes comes with several drawbacks. The cold temperature leads to a sweeter flavor, soggy texture, and reduced nutrition. You also may find they spoil faster in the fridge.
Instead, keep sweet potatoes in a well-ventilated container in a dark area at 55-60°F for 3-5 weeks of optimal storage. Avoid refrigeration to prevent changes in the taste, texture, and nutritional quality.