Do All Potatoes Need To Be Cured Before Eating?

Eating potatoes right from your garden allows you to savor the fresh taste you won’t find in those from the supermarket. However, if you plan to eat them later, curing them is necessary before storage. But do all potatoes need to be cured before eating?

All potatoes of any type need to be cured before storage if they are not being eaten immediately. Curing toughens the skin, heals cuts and blemishes, and helps eliminate bad ones that can spread rot. The curing process keeps the potatoes fresher and extends their storage time.

Curing is a pretty straightforward practice once you get the hang of it. This article will detail everything you need to know about potato curing: what it is, why it is important, how to do it, and if all potatoes need to be cured before eating.

Key Takeaways

  • Necessity of Curing: All potatoes, regardless of type, need to be cured before storage if not eaten immediately. This process toughens the skin, heals blemishes, and helps eliminate bad ones that can spread rot.
  • Curing Conditions: Cure potatoes in an aerated environment at 45-60 °F (7-15.6 °C) and 85-95% humidity for about two weeks.
  • Benefits of Curing: Curing prolongs storage life by toughening the skin, healing cuts, reducing moisture, sorting bad tubers, and preserving the potatoes’ nutritional value and flavor.
  • Storage Recommendations: Post-curing, store potatoes in a dark, cool place with temperatures around 45-50 °F (7-10 °C) and humidity around 90%.

Understanding Potato Curing

Growing your own potatoes offers the satisfaction of consuming fresh food cultivated with your own hands. However, the key to enjoying your home-grown potatoes for months lies in proper storage, specifically through a process known as potato curing.

Potato curing is essential because, like all tubers, potatoes continue physiological processes, such as respiration and transpiration, even after harvest. These processes cause the tubers to lose water, leading to shrinkage and eventual spoilage if not properly managed.

The curing process itself begins right at harvest. It’s best to harvest potatoes when the soil is completely dry. This ensures the tubers are either clean or have minimal dirt, which is crucial for effective curing. Clean potatoes are easier to cure and store, as they reduce the likelihood of issues during the curing process and keep the storage area clean.

Once harvested, potato curing involves the removal of any remnant dirt and drying the potatoes in specific conditions: in an aerated environment at 45-60 °F (7-15.6 °C) and 85-95% humidity for about two weeks.

This process should be conducted in a dry, enclosed space with good ventilation to facilitate air circulation and prevent direct light exposure. Additionally, it’s important to secure the space from rodents and pests to avoid potato damage.

Why Curing Matters

Broadly, potatoes are cured to prolong their storage time.

Here’s how the curing process improves the longevity of your produce:

Toughening the Skin

Tougher skin creates the conditions for them to last for months after harvest. You can tell if they have tough skin if it sticks firmly and is hard to peel off with your thumb.

Healing Blemishes and Cuts

Potatoes with scars and cuts spoil quickly. If the damaged spots are healed during curing, your harvest will last longer in storage.

Reducing Moisture and Ethylene Gas

Moisture is an enemy of long-term tuber storage. Curing would remove unnecessary moisture, especially if the potatoes were harvested when the soil was still wet.

At the correct levels, the naturally-occurring plant regulator inhibits the growth of sprouts. However, unacceptable ethylene levels reduce the sugars in potatoes, which shortens storage time.

Sorting and Cleaning

Potatoes that don’t heal can then be removed before storage, preventing them from spreading rot to the rest of the harvest.

Soil-free potatoes remain fresher and don’t mess up your storage space.

Larger potatoes are best for French fries, while smaller ones are good for roasting. Sorting by variety helps you know which ones to use first, as some types store longer than others. For example, red potatoes last less in storage than the white and yellow varieties. Also, russets have thicker skin and last longer in storage than thin-skinned varieties.

Preserving Phenolic Compounds

(This applies if you cure potatoes before storage.) Phenolic compounds are bioactive compounds in vegetables. In potatoes, these compounds have been associated with health benefits due to their antioxidative properties.

A study found that the action of postharvest potato curing on phenolic compounds positively contributed to the control of browning in freshly cut potatoes. 

Preservation of Potato Quality

If you have a significant harvest from your garden, you won’t be able to consume your potatoes in a week or two. As such, curing the tubers for storage is a necessary step in the storage process.

Good storage preserves potato quality. Poor storage comes with problems like skinning (skin breakage), skin browning, rot, and shriveling (weight loss). In contrast, potatoes stored well tend to last much longer on the shelf and maintain a great deal of their flavor and nutritional value

Curing creates the right conditions for long-term potato preservation. These conditions include tougher potato skin, the elimination of bad tubers, and the removal of unnecessary moisture. 

A postharvest potato curing and storage study found that proper curing with the right temperature and humidity had significant benefits.

Besides, more extended curing periods (14 days compared to 7 days) had better results, like:

  • Lower potato rot
  • Lower potato skin browning
  • Less potato shriveling
  • Lower percentage of weight loss
  • Lower incidence of storage-related diseases
  • Lower nutrient loss

These benefits should persuade any potato grower to cure their harvest before storage to slow down their deterioration. 

How to Cure Potatoes

As mentioned, curing begins while the tubers are still in the garden. The preharvest aspect of potato curing involves letting the stalks dry completely. The potatoes are then left in the soil for a week or two. Doing so will enhance skin hardening even before the actual curing process. 

In addition, harvesting should be done when the ground is completely dry. Harvesting when the soil is dry limits the amount of dirt stuck to the potatoes and leaves out unnecessary moisture.

On harvesting day, leaving the potatoes in the sun for a short while will initiate the drying process. However, leave them under the sun for a short time.  

Too much direct sunlight turns them green. A neurotoxin known as solanine is responsible for the green color of potatoes that are left out in the sun for too long. Solanine is poisonous and can even be fatal if consumed in large amounts.

Once harvested, follow these steps for curing:

1. Brush Off Any Excess Soil on the Potatoes

Potatoes grown on sandy and loam soils may not require brushing, as the soil easily falls off the tuber. Those harvested from clay soils require a bit more work.

Although you will find advice directing you to wash off sticky clay soil from your harvest, you should know that washing your potatoes before storage facilitates spoilage. Rubbing them hard will rub away part of the skin or cause cuts, spoiling the tubers in the process.

2. Set the Potatoes for Curing in a Conducive Environment

Place the potatoes in crates, slatted wood boxes, or a harvest rack so that air will pass freely through the tubers during the curing period.

Potato curing temperatures should range between 45 and 60 °F (7 and 15.6 °C). The humidity level should be around 85% to 95%.

Leave the potatoes to cure for two weeks. During this time, any bruises on the tuber will heal, and the skin will toughen.

3. Sort the Potatoes

When the two-week curing period is over, it will be easier to notice any damage. Remove any potatoes that feel soft at a slight push with the finger. Do the same with those that show signs of rot and those that are wilted. 

The remaining healthy tubers are ready for long-term storage at this point.

4. Store the Cured Potatoes

Arrange the cured potatoes on shelves in a dark location in your house. Alternatively, put them in crates, baskets, or cardboard boxes with aeration. 

Don’t over pile them in these containers, as this can facilitate rot. Brown bags can also be used, but not plastic bags because they don’t allow air circulation through the tubers.

Basements, garages, and barns work well for potato storage. Ensure your potatoes are not exposed to light. They should also be stored away from other fruits and vegetables to control ethylene levels.

When storing your cured potatoes, keep the storage temperatures at 45-50 °F (7-10 °C) and the humidity at around 90%

Lower temperatures can chill the potatoes and cause a sugary taste. Higher temperatures and exposure to light will make them grow sprouts.

Final Thoughts

Harvested potatoes should be cured to prolong their storage life. Curing entails removing any dirt left on the tubers before leaving them under the right temperature and humidity levels to dry and toughen the skin for two weeks. 

Curing is a must-do before storage if you want your homegrown potatoes to remain fresh for months.

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of TheGrowingLeaf.com, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

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