How to crystallize plums?

To crystallize plums, you gradually infuse them with sugar syrup over several days, then dry them, resulting in translucent, sweet fruit with a delicate sugary coating.

The Art of Crystallizing Plums

Crystallized or candied plums are a delightful treat, perfect for snacking, garnishing desserts, or adding to baked goods. The process involves replacing the fruit's water content with sugar, which acts as a preservative and gives the plums their signature texture and sweetness.

Understanding the Process

The core idea behind crystallizing fruit is osmosis: sugar from a concentrated syrup slowly permeates the fruit, drawing out water. To prevent the plums from shriveling, this process is done gradually, increasing the sugar concentration of the syrup over multiple stages.

Step-by-Step Guide to Crystallizing Plums

Here’s a detailed guide to help you create perfectly crystallized plums:

1. Plum Preparation

Select Plums: Choose firm, ripe plums that are free from blemishes. European plums (like Italian prune plums) or firmer varieties work best, as they hold their shape well.
Wash and Prepare: Thoroughly wash the plums under cold running water. You can leave them whole, halve them, or slice them, depending on your preference. For whole plums, a small incision might help with syrup penetration. Halving and pitting them is a common approach.

2. Initial Syrup Infusion

This is the crucial first step where the plums begin to absorb sugar.

Combine Ingredients: Place the prepared plums in a large stock pot. For a basic syrup, you'll need approximately equal weights of sugar and water (e.g., 500g sugar to 500ml water) to cover the fruit.
Initial Heating: Place the pot on a heat source and bring the mixture to a boil. This helps to start the osmosis process and soften the plums slightly.
First Rest: Once boiling, remove the pot from the heat. Cover the mixture and leave it to rest for three days. This allows the plums to slowly absorb the initial sugar syrup and release some of their natural moisture without cooking them excessively.

3. Subsequent Syrup Concentration

After the initial infusion, the syrup needs to be strengthened to continue the crystallization process effectively.

Separate Fruit and Syrup: Carefully remove the plums from the syrup and set them aside.
Boil and Skim Syrup: Bring the reserved syrup back to a boil. Keep it at a rolling boil for at least half an hour. During this time, skim off any impurities that rise to the surface. This concentrated syrup will be reused.
Add More Sugar: For the next stage, add more sugar to the syrup (e.g., an additional 150-200g per 500ml of original water). Bring it to a boil again to dissolve the new sugar.
Second Infusion: Pour the newly concentrated hot syrup over the plums in a clean pot or bowl. Let it sit, covered, for another 2-3 days.
Repeat: Repeat the process of separating fruit, boiling/skimming syrup, adding more sugar, and re-infusing the plums every 2-3 days. You will typically do this 3-5 times, gradually increasing the sugar concentration each time until the syrup reaches a density where it measures around 70-75° Brix (a thick, syrupy consistency). This gradual process ensures the plums retain their shape and don't become tough.

4. Drying the Plums

Once the plums are thoroughly saturated with sugar, they need to be dried.

Drain Plums: Carefully remove the plums from the final, thick syrup. Let them drain on a wire rack placed over a baking sheet to catch excess syrup.
Initial Air Drying: Allow the plums to air dry at room temperature for several hours or overnight.
Oven Drying (Optional): For faster drying, you can place the plums on parchment-lined baking sheets in an oven set to its lowest temperature (around 100-150°F or 40-65°C) with the door slightly ajar. Dry them for several hours, turning occasionally, until they are no longer sticky but still pliable. Alternatively, a food dehydrator works well.
Finishing Touch: Once mostly dry, you can roll the plums lightly in granulated sugar for a traditional crystallized finish. This also helps prevent sticking.

Essential Tips for Success

Patience is Key: Crystallizing fruit is a slow process. Rushing it can lead to shriveled or hardened plums.
Hygiene: Ensure all your equipment is clean to prevent mold growth during the long infusion periods.
Syrup Control: The gradual increase in sugar concentration is critical. Too much sugar too soon can "shock" the fruit, causing it to toughen.
Leftover Syrup: Don't discard the leftover syrup! It's a rich, plum-flavored syrup perfect for cocktails, drizzling over pancakes, or sweetening tea.
Preventing Mold: If you see any signs of mold during the resting periods, discard the batch and start over. Ensuring the syrup is hot when poured over the fruit and maintaining proper sugar concentration helps prevent this.

Storage of Crystallized Plums

Store crystallized plums in an airtight container at room temperature for up to two weeks, or in the refrigerator for several months. For longer storage, they can be frozen for up to a year. Layer them with parchment paper to prevent sticking.

Culinary Uses

Crystallized plums are wonderfully versatile:

Snacking: Enjoy them as a sweet treat on their own.
Baking: Add them to fruitcakes, muffins, scones, or bread puddings.
Garnishes: Use them to decorate cakes, tarts, and other desserts.
Cheese Boards: Pair them with cheeses for a sophisticated appetizer.

Summary Table: Key Stages of Plum Crystallization

Stage	Description	Duration	Key Action
1. Preparation	Washing and preparing plums (e.g., halving, pitting).	15-30 mins	Choose firm, ripe plums.
2. Initial Infusion	Plums placed in sugar syrup, boiled once, and rested.	3 days	Initial sugar absorption.
3. Syrup Concentration	Fruit removed, syrup boiled/skimmed, more sugar added, re-infused.	3-5 cycles (2-3 days each)	Gradually increase sugar concentration; prevents shriveling.
4. Drying	Drained plums air-dried, optionally with low heat, then sugar-coated.	1-3 days	Removes remaining moisture, creates a lasting finish.

Ora