How to preserve uncarved pumpkins

In this brief guide, we are going to answer the question “how to preserve uncarved pumpkins” and discuss the different methods of preserving uncarved pumpkins.

How to preserve uncarved pumpkins

The total global production of watermelons, pumpkins, squash (Cucurbita maxima, Duschesne), and gourds (Lagenaria siceraria, (Molina) Standl) is approximately 123.3 million tonnes annually, of which 8.1% is from Africa (1).

Uncarved pumpkins can be preserved by :

  • Washing with a bleach solution, vinegar or dish soap.
  • Properly storing uncarved pumpkins at room temperature.
  • Coat with petroleum jelly or WD-40.

‘Connecticut Field’ is the standard general purpose or large Halloween pumpkin that is used more than any other variety for carving into a jack o’lantern. Fruits have a hard orange, smooth, and slightly ribbed skin (2).

Carving pumpkins are used for Halloween decorations. Carving pumpkins are edible but they are not as delicious as cooking pumpkins. They are watery with little flesh and thinner skins. It is important not to consume any pumpkins preserved using bleach, WD-40 or petroleum jelly.

Before being carved, the pumpkins can be preserved by proper storage at room temperature. 

How to wash uncarved pumpkins

The first step to preserving uncarved pumpkins is proper cleaning. Cleaning the exterior will remove any microbes that result in spoilage. 

Washing and sanitizing are important steps on the reduction of microbial contamination of fruits and vegetables. In addition, pumpkins often have punctures, cuts, or splits that might be sites for bacterial attachment. Therefore, it is important to eliminate bacteria and molds in order to extend the shelf life of the stored pumpkin. Washing with water and brush can eliminate dirt and debris, while sanitizing reduces exponentially the microbial counts of the fruits. Chlorine is the most widely used among the washing and sanitizing agents available for fresh produce; it is generally assumed that chlorine is highly effective in reducing bacterial populations on commodity surfaces. Numerous commercial washing formulations have been developed for fruits and vegetables. Hydrogen peroxide, is a versatile and widely used oxidative bleaching agent, is effective against a wide range of bacteria but less active against fungi (4).

Uncarved pumpkins can be washed in one of 3 ways:

Washing with a bleach solution 

  • Prepare a bleach solution by mixing 1 part of bleach in 10 parts of water. 
  • Spray the whole exterior of the pumpkins with the bleach solution and scrub with a soft, clean brush to remove dirt. An alternative method is to soak the uncarved pumpkins in the bleach solution for about 20 minutes. 
  • Allow the pumpkins to air dry.

Washing with a vinegar solution

  • Prepare a vinegar solution by mixing 1 part of vinegar with 3 parts of water.
  • Soak the uncarved pumpkins in the vinegar solution for about 20 minutes.
  • Scrub with a soft, clean brush to remove dirt.
  • Allow the pumpkins to air dry.

Most food-borne bacterial pathogens cannot survive for long periods of time or grow at pH of less than 4.5 Thus, vinegar having a pH of 3, shown to have bacteriostatic and bactericidal effect on microbes antimicrobial effect of vinegar is dependent on the concentration, the type of microorganism, the strain, and the contact time. The research aimed at investigating the sanitizing effect of vinegar on some sliced fruits and vegetables (6).

Washing with dish soap and water

  • Wash the pumpkins with water and dish soap. 
  • Scrub with a soft, clean brush to remove dirt.
  • Allow the pumpkins to air dry.

How to store uncarved pumpkins

Raw uncarved pumpkins preserve well at room temperature. A properly stored raw, uncarved pumpkin can last for about 3 to 4 months. The following storage conditions preserve whole uncarved pumpkins for a longer time.

Store  pumpkins in a dry (70% RH) and cool (50°F–60°F) place. Spread out the pumpkins rather than stacking them up. Decay is the main source of loss. Some good results have been obtained by curing pumpkins before storing. This was done by keeping them for 10 days at 80°F–85°F and a high relative humidity (80%–85%) (2).

  • Uncarved pumpkins must not be refrigerated or frozen. Uncarved pumpkins must be stored in a cool, dark and dry place. Moisture will cause rapid spoilage of uncarved pumpkins.
  • Uncarved pumpkins must not be kept directly on the floor. Always keep them on a dry mat or a clean crate. Placing them directly on the floor may attract insects.
  • Place the uncarved pumpkins upside down so that the stalk is facing the floor.

How to preserve uncarved pumpkins with WD-40 and petroleum jelly

Coatings are used on specific types of fruits and vegetables to prevent the loss of moisture, protect the commodities from bruising, and add various degrees of sheen. However, food-use applications of mineral hydrocarbons, including white mineral oils, paraffin waxes, microcrystalline waxes and petrolatum, derived from petroleum sources result in dietary exposure to these compounds by consumers.

WD-40 is a lubricant used to protect metals from rusting. WD-40 protects uncarved pumpkins by acting as a sealant and a lubricant. WD-40 displaces moisture and keeps away insects and bacteria. This prevents the pumpkins from rotting. However, it should not be used for food, since it is not approved by the FDA as a food grade product.

Alternatively, you can coat the uncarved pumpkins with petroleum jelly. Petroleum jelly will also work as a lubricant and sealant and prevent the pumpkins from rotting.

Make sure that the uncarved pumpkins are washed, cleaned and completely dry before applying WD-40 or petroleum jelly.

Using WD-40 and petroleum jelly preserves uncarved pumpkins for about 3 months.

Additional tips to preserve uncarved pumpkins

There are other household methods to preserve uncarved pumpkins. Some of these are:

  1. Use rubbing alcohol: Rubbing alcohol is a powerful disinfectant and will kill most of the bacteria that cause spoilage. 

To preserve uncarved pumpkins with rubbing alcohol:

  • Wash the pumpkins in a bleach solution, vinegar solution or dish soap and water.
  • Spray the pumpkins with rubbing alcohol. Well-known for its antimycotic effect, ethanol has also been investigated as a potential barrier to inhibit the growth of C. botulinum
  • Allow the pumpkins to air dry.
  1. Protect from animals: Insects, squirrels and rodents are a major threat to uncarved pumpkins. It is recommended to use homemade animal repellents. Several animal repellents can be easily made at home.

To make an animal repellent from hot sauce: 

  • Use a mixture of hot sauce, dish soap and water: Mix hot sauce, dish soap and water. Spray the surrounding area of the pumpkin with the mixture. The method for making a repellent for carved pumpkins can be found here.

To preserve uncarved pumpkins from animals:

  • Store uncarved pumpkins in an area unreachable by animals. For example in a closed garage or a basement.
  • Spray repellents on and around the pumpkin. Make sure that other vegetables are not stored nearby.
  1. Store the uncarved pumpkins away from ethylene producing fruits and vegetables: Some fruits and vegetables release ethylene gas during the ripening process. Ethylene causes nearby fruits and vegetables to ripen as well

To preserve uncarved pumpkins from ethylene:

  • Store the uncarved pumpkins away from ethylene producers such as apples, peaches, melons and pears.

Ethylene is produced endogenously by perhaps all plants and their organs. At very low concentrations it can induce a wide array of physiological responses, including altered geotropic growth, abscission, ripening, senescence, and physiological disorders (7).

  1. Maintain good ventilation in the pumpkin storage area: Make sure that the area your uncarved pumpkins are stored in is not too humid or hot. You can place a portable fan during the daytime when temperatures get too high.

Other FAQs about Pumpkin that you may be interested in.

How to preserve pumpkins

Can you eat whole pumpkin seeds?

Conclusion

In this brief guide, we answered the question “how to preserve uncarved pumpkins” and discussed the different methods used to preserve uncarved pumpkins.

If you have any questions or comments, please let us know.

References

  1. Masika, Fred B., et al. Pumpkin and watermelon production constraints and management practices in Uganda. Cabi Agri Biosci, 2022, 3. 
  2. Stephens, James M. Pumpkin–Cucurbita Spp. University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS, 1994.
  3. Howell, J., et al. Pumpkin and Winter Squash Harvest and Storage. 2009. University of Massachusetts. 
  4. Sapers, Gerald M. Washing and sanitizing raw materials for minimally processed fruit and vegetable products. CRC Press: Boca Raton, FL, London, New York, Washington, DC, 2003.
  5. Heimbach, J. T., et al. Dietary exposures to mineral hydrocarbons from food-use applications in the United States. Food chem toxicol, 2002, 40, 555-571.
  6. Kabir, A., M. M. Adda’u, and M. M. Idris. Sanitizing effect of acetic acid (vinegar) on some sliced fruits and vegetables in Kabuga Kano, Nigeria. Bayero J Pure Appl Sci, 2017, 10, 272-275.
  7. Watada, ALLEY E. Effects of ethylene on the quality of fruits and vegetables. Food Technol, 1986, 40, 82-85.