Plums are a delicious and nutritious fruit enjoyed by people worldwide. Whether you prefer them sweet and juicy or tart and tangy, plums are a versatile fruit that can be eaten fresh, used in baking, or made into jams and preserves. However, have you ever wondered what happens to plums after they’re picked from the tree? Do they continue to ripen, or do they remain in the same state forever? In this article, we’ll delve into the world of plum ripening and explore the factors that affect the ripening process.
Understanding Plum Ripening
Plum ripening is a complex process that involves a series of biochemical reactions. These reactions are triggered by the production of ethylene gas, a natural plant hormone that promotes fruit ripening. As plums mature on the tree, they produce more ethylene gas, which stimulates the breakdown of cell walls and the conversion of starches into sugars. This process makes the fruit softer, sweeter, and more flavorful.
The Role of Ethylene Gas in Plum Ripening
Ethylene gas plays a crucial role in plum ripening. As plums produce more ethylene gas, they trigger a series of reactions that promote ripening. These reactions include:
- The breakdown of cell walls, which makes the fruit softer and more prone to spoilage
- The conversion of starches into sugars, which makes the fruit sweeter and more flavorful
- The production of enzymes that break down the fruit’s natural defenses, making it more susceptible to decay
How Ethylene Gas Affects Plum Ripening After Picking
When plums are picked from the tree, they continue to produce ethylene gas, albeit at a slower rate. This means that plums will continue to ripen after they’re picked, but the rate of ripening will depend on various factors, including:
- The plum variety: Some plum varieties, such as ‘Santa Rosa’ and ‘Methley’, are more prone to ripening after picking than others.
- The stage of ripeness at picking: Plums that are picked when they’re greener will take longer to ripen than those that are picked when they’re more mature.
- Storage conditions: Plums that are stored in a cool, dry place will ripen more slowly than those that are stored at room temperature.
Factors That Affect Plum Ripening After Picking
While ethylene gas plays a significant role in plum ripening, other factors can affect the ripening process after picking. These factors include:
Temperature
Temperature is a critical factor in plum ripening. Plums that are stored at room temperature (around 68°F to 72°F) will ripen more quickly than those that are stored in the refrigerator (around 32°F to 40°F). However, plums that are stored at very high temperatures (above 75°F) may ripen too quickly and become overripe.
Optimal Storage Temperature for Plums
The optimal storage temperature for plums depends on the variety and the stage of ripeness. Generally, plums can be stored at the following temperatures:
- 32°F to 40°F (0°C to 4°C) for up to 2 weeks
- 40°F to 50°F (4°C to 10°C) for up to 1 week
- 50°F to 60°F (10°C to 15°C) for up to 3 days
Humidity
Humidity also plays a role in plum ripening. Plums that are stored in a humid environment (above 80%) will ripen more quickly than those that are stored in a dry environment (below 60%). However, plums that are stored in an environment that is too humid may become overripe and develop mold.
Optimal Storage Humidity for Plums
The optimal storage humidity for plums depends on the variety and the stage of ripeness. Generally, plums can be stored at the following humidities:
- 60% to 70% for up to 2 weeks
- 70% to 80% for up to 1 week
- 80% to 90% for up to 3 days
Light
Light can also affect plum ripening. Plums that are exposed to direct sunlight will ripen more quickly than those that are stored in the dark. However, plums that are exposed to too much light may become overripe and develop sunscald.
Optimal Storage Light for Plums
The optimal storage light for plums depends on the variety and the stage of ripeness. Generally, plums can be stored in the following light conditions:
- Low light (less than 10 foot-candles) for up to 2 weeks
- Medium light (10 to 20 foot-candles) for up to 1 week
- High light (above 20 foot-candles) for up to 3 days
How to Ripen Plums After Picking
If you’ve picked plums that are not yet ripe, you can speed up the ripening process by following these tips:
Store Plums at Room Temperature
Store plums at room temperature (around 68°F to 72°F) to promote ripening. Avoid storing plums in the refrigerator, as the cold temperature will slow down the ripening process.
Use Ethylene Gas
You can use ethylene gas to promote plum ripening. Place the plums in a paper bag with an apple or banana, which will produce ethylene gas and stimulate ripening.
Monitor Plums for Ripeness
Check plums regularly for ripeness. A ripe plum will be slightly soft to the touch, have a sweet aroma, and be slightly indented around the stem.
Conclusion
In conclusion, plums do continue to ripen after they’re picked from the tree. The rate of ripening depends on various factors, including the plum variety, stage of ripeness at picking, storage conditions, temperature, humidity, and light. By understanding these factors and following the tips outlined in this article, you can promote plum ripening and enjoy delicious, juicy plums all year round.
Additional Tips for Plum Ripening
Here are some additional tips for plum ripening:
- Handle plums gently to avoid bruising, which can promote spoilage.
- Store plums away from strong-smelling foods, as they can absorb odors easily.
- Don’t wash plums before storing them, as excess moisture can promote mold and spoilage.
- Use plums within a few days of ripening, as they will continue to ripen and eventually spoil.
By following these tips and understanding the factors that affect plum ripening, you can enjoy delicious, ripe plums all year round.
Do Plums Continue to Ripen When Picked?
Yes, plums do continue to ripen when picked. This process is known as post-harvest ripening. Plums, like many other stone fruits, produce ethylene gas as they ripen. Ethylene promotes a series of biochemical reactions that help to soften the fruit, break down cell walls, and develop the characteristic flavor and aroma of a ripe plum. Even after being picked, plums will continue to produce ethylene, which triggers these ripening processes.
However, the rate and extent of post-harvest ripening can vary depending on factors such as the plum variety, the stage of ripeness at harvest, and storage conditions. For example, plums that are picked when they are greener and less ripe will typically continue to ripen more slowly than those picked at a riper stage. Similarly, storing plums in a cool, dry place can slow down the ripening process, while warmer temperatures and higher humidity can accelerate it.
How Do I Know When Plums Are Ripe and Ready to Pick?
There are several ways to determine if plums are ripe and ready to pick. One of the most obvious signs is a change in color. As plums ripen, they will typically turn from green to a deeper shade of red, purple, or yellow, depending on the variety. You can also check for ripeness by gently tugging on the plum. A ripe plum will come off the tree easily, while an unripe one will be more difficult to remove.
Another way to check for ripeness is to give the plum a sniff. Ripe plums give off a sweet, fruity aroma that is hard to miss. You can also check the plum’s texture by gently squeezing it. A ripe plum will be slightly soft to the touch, but still firm enough to hold its shape. Avoid squeezing too hard, as this can damage the fruit and cause it to spoil more quickly.
Can I Speed Up the Ripening Process for Plums?
Yes, there are several ways to speed up the ripening process for plums. One of the most effective methods is to store them in a paper bag with an apple or banana. These fruits produce more ethylene gas than plums, which can help to stimulate the ripening process. You can also try storing plums in a warm, dry place, such as a sunny windowsill or a fruit bowl.
Another way to speed up ripening is to use a fruit ripening bag or container. These bags are designed to trap ethylene gas and maintain high humidity, creating an ideal environment for fruit to ripen. You can also try wrapping plums in a cloth or paper towel to create a mini-greenhouse effect. However, be careful not to over-ripen your plums, as this can cause them to spoil more quickly.
How Do I Store Plums to Keep Them Fresh for Longer?
To keep plums fresh for longer, it’s essential to store them properly. One of the most important things is to keep them cool and dry. Plums should be stored in a refrigerator at a temperature between 32°F and 40°F (0°C and 4°C). You can store them in a plastic bag or airtight container to maintain humidity and prevent moisture from accumulating.
It’s also essential to handle plums gently to avoid bruising or damaging the fruit. You can store plums separately or together, but make sure they are not touching each other. This can help to prevent the spread of mold and bacteria. Finally, check on your plums regularly to remove any that are spoiling, as this can affect the rest of the fruit.
Can I Freeze Plums to Enjoy Them Year-Round?
Yes, you can freeze plums to enjoy them year-round. Freezing is an excellent way to preserve plums, as it helps to lock in their flavor, texture, and nutrients. To freeze plums, start by washing and drying them thoroughly. Then, remove the pits and slice or chop the fruit into desired portions.
Next, spread the plum pieces out in a single layer on a baking sheet and place them in the freezer. Once frozen, transfer the plums to an airtight container or freezer bag and store them in the freezer at 0°F (-18°C) or below. Frozen plums are perfect for using in baked goods, smoothies, or as a topping for yogurt or oatmeal. You can also use them to make jam, preserves, or chutney.
Are There Any Plum Varieties That Don’t Ripen Well Off the Tree?
Yes, there are some plum varieties that don’t ripen well off the tree. These varieties are often referred to as “clingstone” plums, which means that the flesh clings to the pit. Clingstone plums tend to be more difficult to ripen off the tree, as they have a lower ethylene production rate than other varieties.
Examples of clingstone plum varieties include ‘Santa Rosa’ and ‘Methley’. These plums are best enjoyed when picked at the peak of ripeness, as they may not continue to ripen as well off the tree. On the other hand, “freestone” plum varieties, such as ‘Italian Prune’ and ‘Stanley’, tend to ripen more easily off the tree and are often preferred for their sweet flavor and tender texture.
Can I Grow My Own Plum Tree to Enjoy Fresh Plums Year-Round?
Yes, you can grow your own plum tree to enjoy fresh plums year-round. Plum trees are relatively easy to grow, provided you have the right climate and soil conditions. Plum trees prefer well-draining soil and full sun to partial shade. They also require regular watering and fertilization to promote healthy growth and fruit production.
When selecting a plum tree variety, consider factors such as climate, soil type, and desired fruit characteristics. Some popular plum tree varieties for home gardeners include ‘Santa Rosa’, ‘Methley’, and ‘Italian Prune’. With proper care and maintenance, a plum tree can provide you with a bountiful harvest of fresh plums for years to come. However, keep in mind that plum trees typically take 2-5 years to mature and produce fruit after planting.