Juicing plums is straightforward whether you own a dedicated juicer, a steam juicer, or just a blender and a straining bag. The key step that sets plums apart from most fruits: you need to remove the pits first (unless you’re steam juicing), because plum kernels contain a compound that releases hydrogen cyanide when crushed. Beyond that, plums juice easily and produce a rich, naturally sweet liquid packed with sorbitol and polyphenols.
Remove the Pits First
Plum pits aren’t just hard on your equipment. The kernel inside contains amygdalin, a compound that releases hydrogen cyanide when the tissue is crushed or broken down. Plum kernels carry roughly 696 mg of hydrogen cyanide per kilogram of kernel material, which puts them on par with peach and apple seeds. A centrifugal or masticating juicer will crack those pits, so you need to halve each plum and pop the pit out before feeding it through. A paring knife run around the seam of the plum makes this quick work.
The one exception is steam juicing, where whole plums sit in a basket above boiling water and the pit never gets crushed. More on that method below.
Electric Juicer Method
If you have a centrifugal or masticating juicer, this is the fastest route to fresh plum juice.
Wash your plums, cut them in half, and remove the pits. You don’t need to peel them. Feed the halves through the juicer’s chute. A masticating (slow) juicer will give you a better yield, squeezing more liquid from the same amount of fruit. It also introduces less heat and oxygen, which helps preserve nutrients and color. The trade-off is that masticating juicers tend to produce thicker, pulpier juice that can be foamy. Centrifugal juicers spin at 6,000 to 14,000 RPM, working much faster but leaving the leftover pulp noticeably wetter, meaning you’re losing more juice to the waste bin.
Plum juice oxidizes and darkens quickly once exposed to air. To keep the color vibrant, you can add a splash of lemon juice to your finished product. A more effective option is dissolving a teaspoon of pure ascorbic acid (vitamin C powder) in a gallon of cold water and mixing a small amount into your juice. Lemon juice works in a pinch but isn’t as effective at preventing browning.
Blender and Straining Bag Method
No juicer? A blender works well for plums since they’re soft enough to puree completely. Wash the plums, halve and pit them, then add them to your blender with just enough water to get things moving, usually about a quarter cup per pound of fruit. Blend on high until smooth.
Pour the puree through a fine-mesh nut milk bag or cheesecloth draped over a bowl. A nut milk bag gives you the most control because you can squeeze the pulp firmly to extract every bit of liquid. Gather the top of the bag and twist, pressing the pulp into a tight ball. You’ll get a slightly thicker juice than a dedicated juicer produces, but the flavor is identical. If you want it thinner, strain it a second time or add a small amount of water.
Steam Juicer Method
A steam juicer is the best option if you’re processing a large batch of plums, especially if you plan to can the juice for long-term storage. It produces crystal-clear juice with no pulp, and you don’t even need to pit the plums.
Wash the plums and load them whole into the top basket of the steam juicer. Fill the bottom pot with water and bring it to a boil. Steam rises through the middle collection pot, breaks down the fruit in the top basket, and the juice drains into the collector. Once juice starts flowing through the tube, drain it into clean containers. The whole process takes about an hour. Because the pits sit intact in the basket and never get crushed, there’s no concern about amygdalin leaching into your juice.
Plums are naturally acidic, with a pH ranging from 2.8 to 4.3 depending on variety. That means steam-extracted plum juice is safe for water bath canning without adding lemon juice or citric acid. Fill pint or quart jars leaving a quarter inch of headspace and process in a water bath canner for 15 minutes, adding extra time if you’re at higher elevation. Blue and purple plum varieties tend to be more acidic than yellow or red ones.
How Long Fresh Plum Juice Lasts
Fresh, unpasteurized plum juice keeps in the refrigerator for up to 72 hours when stored in an airtight container. After that point, the taste and texture start to change noticeably. Juice from a centrifugal juicer degrades faster because the high-speed spinning introduces more oxygen during extraction. If you used a slow juicer or the blender method and sealed the juice tightly, you can expect the full three-day window.
For longer storage without canning, you can freeze plum juice in mason jars (leave an inch of headspace for expansion) or in ice cube trays for easy portioning. Frozen plum juice holds its flavor for several months.
Digestive Effects Worth Knowing
Plum juice has a mild natural laxative effect, and this is worth knowing before you drink a large glass on an empty stomach. The culprit is sorbitol, a sugar alcohol found at about 6.1 grams per 100 grams of prune juice. Fresh plum juice contains less sorbitol than prune juice (prunes are just dried plums with a more concentrated sorbitol level of 14.7 g per 100 g), but it’s still enough to loosen things up, especially if you’re not used to it.
Plum juice also raises blood sugar faster than eating whole plums. When you juice any fruit, you remove most of the fiber that slows digestion and moderates insulin response. Without that fiber, the natural sugars hit your bloodstream more quickly. Studies on fruit juice versus whole fruit consistently show that whole fruits produce more favorable insulin and glucose responses. This doesn’t mean plum juice is unhealthy, but if you’re watching your blood sugar, smaller portions or diluting the juice with water makes a difference.
Picking the Right Plums
Ripe plums juice best. They should give slightly when pressed but not feel mushy. Overripe plums still work and actually yield more juice, though the flavor can lean fermented if they’ve gone too far. Underripe plums produce a more tart, astringent juice and are harder to extract liquid from.
Darker varieties like Italian prune plums and Damson plums produce a deep, richly flavored juice that’s excellent for canning or mixing into cocktails. Japanese varieties (the large, round plums you typically find at grocery stores) give a milder, sweeter juice with a lighter color. Mixing varieties is a good strategy if you want complexity without too much tartness.