Every spring, rhubarb starts making an appearance at farmers’ markets, grocery stores, and gardens.
Those long, ruby-red and green stalks are one of the season’s most distinctive ingredients. They’re incredibly tart, wonderfully fragrant when cooked, and perfect for pies, crisps, crumbles, sauces, and jams.
But there is one thing about rhubarb that can make a first-time cook hesitate:
It can be surprisingly bitter and aggressively sour.
That’s exactly what happened when I gathered a batch of spring rhubarb stalks for a pie.
The stalks looked beautiful.
They were firm, crisp, and brightly colored.
But when I tasted a tiny piece of the raw stalk, the flavor was intensely tart with a slightly bitter edge.
I didn’t want to make a pie that required an enormous amount of sugar just to make the rhubarb pleasant.
So I tried something I had heard about from old-fashioned kitchen advice.
I put the chopped rhubarb into a bowl of ice-cold salted water.
I left it there for about 30 minutes.
Then I drained it, rinsed it, and prepared the pie.
What happened next was interesting—but not quite for the reason I initially thought.
First, Let’s Clear Up One Important Rhubarb Safety Rule
Before talking about the salt-water experiment, there’s one rhubarb rule that should never be forgotten:
Use the stalks, but don’t eat rhubarb leaves.
Rhubarb leaves contain much higher concentrations of oxalic acid and other compounds than the stalks.
The stalks are the part traditionally used for food.
So when preparing rhubarb, remove the leaves completely and discard them.
Don’t try to use the leaves in a salad, smoothie, soup, or recipe.
The colorful stalks are what you want.
Why Was My Rhubarb So Bitter?
Rhubarb naturally has an intense sourness.
That’s one of its defining characteristics.
It contains organic acids, particularly oxalic acid, which contributes to its characteristic tartness.
That acidity is why rhubarb is so often paired with sugar.
Strawberries, for example, are a classic partner because their sweetness helps balance rhubarb’s sharp acidity.
But there is a difference between tart and bitter.
Good rhubarb can be intensely sour without necessarily tasting unpleasantly bitter.
If your rhubarb tastes unusually bitter, the variety, growing conditions, age, and preparation can all influence the experience.
The salt-water soak seemed like a simple way to see whether some of that harshness could be reduced.
I Started With Ice-Cold Water
I filled a large bowl with very cold water and added ice.
Then I stirred in salt.
The idea was simple.
The rhubarb would sit in the cold salted water for approximately 30 minutes before being drained.
I wasn’t trying to cook it.
I wasn’t trying to pickle it.
I simply wanted to see whether soaking would change the flavor and texture before the rhubarb went into the pie.
The cold water also helped keep the stalks crisp while they soaked.
That’s important because rhubarb is a vegetable with a naturally crunchy, juicy texture when raw.
I didn’t want the stalks sitting in warm water and becoming soft.
What Happened During the 30 Minutes?
The first noticeable change was visual.
The water became slightly cloudy.
Some of the surface color appeared to leach into the water, particularly from pieces with more exposed cut surfaces.
The rhubarb also became noticeably colder and remained quite crisp.
When I picked up a piece after the soak, it still had that characteristic firm, crunchy texture.
It hadn’t become mushy.
That was encouraging.
But the real test was the flavor.
The Rhubarb Tasted Less Aggressive
After draining and rinsing the rhubarb, I tasted another small piece.
The result wasn’t magical.
The rhubarb hadn’t suddenly become sweet.
It was still very tart.
But the flavor seemed somewhat less harsh.
The sharpest edge had softened.
And this is where it’s important to separate what the salt-water soak may do from what it cannot do.
A short soak isn’t going to transform naturally sour rhubarb into sweet fruit.
Rhubarb is still rhubarb.
The main effect of soaking is likely related to soluble compounds and water exchange at the surface rather than somehow removing all of the acids responsible for rhubarb’s characteristic flavor.
In other words:
The soak can change the intensity of the raw flavor, but it doesn’t eliminate rhubarb’s natural tartness.
And for pie, that’s actually a good thing.
Why Does Salt Change the Taste?
Salt has a fascinating effect on flavor.
It doesn’t simply make food taste salty.
In small amounts, salt can suppress certain bitter notes and alter how we perceive sweetness and acidity.
That’s one reason cooks use small amounts of salt in desserts.
Think about chocolate chip cookies.
There may be only a small amount of salt in the dough, but that salt helps balance the sweetness and enhance the overall flavor.
The same general flavor principle applies here.
The salt in the soaking water may help change the perception of the rhubarb’s bitterness.
However, that doesn’t mean salt magically removes all bitterness.
And it doesn’t mean you should use an extremely salty solution.
Too much salt can simply make your rhubarb taste salty.
The Ice-Cold Water Was More About Texture Than Flavor
The ice was probably less important for removing bitterness than the salt.
Its biggest advantage was helping keep the rhubarb crisp.
Cold water helps firm up many raw vegetables.
If you’re preparing rhubarb ahead of time, soaking it briefly in cold water can help maintain that fresh, crunchy texture before cooking.
But you don’t need an enormous amount of ice.
The goal is simply to keep the soaking water cold.
Then Came the Pie
After the 30-minute soak, I drained the rhubarb thoroughly.
This part matters.
Rhubarb contains a lot of water naturally, and adding extra soaking water to a pie filling isn’t something you want.
I rinsed away the excess salt and then let the stalks drain.
For a pie, you want to control the amount of liquid going into the filling.
Otherwise, you can end up with a watery filling and a soggy crust.
After draining, I mixed the rhubarb with sugar and the other ingredients for the filling.
Then it went into the pie crust.
The Finished Pie Was Still Tart
If you are expecting salted rhubarb to come out of the oven tasting like strawberries, you’ll be disappointed.
The finished pie still had the unmistakable flavor of rhubarb.
It was tart.
It was bright.
It had that characteristic springtime sharpness.
But the flavor seemed more balanced.
Instead of one aggressive sour note hitting immediately, the sweetness of the pie filling had more room to come through.
That’s exactly what I wanted.
The goal wasn’t to remove rhubarb’s personality.
It was to make that personality easier to enjoy.
Why You Still Need Sugar
One common misconception about soaking rhubarb is that you can use it to eliminate the need for sugar.
That’s not really how it works.
Rhubarb is naturally tart.
If you’re making a traditional rhubarb pie, sugar is still an important part of the recipe.
The amount depends on your variety of rhubarb, personal preference, and what other fruit you’re using.
Strawberries, apples, raspberries, and other sweet fruits can reduce the amount of added sugar needed.
But a salt-water soak isn’t a substitute for balancing the filling.
Think of it as a small preparation step rather than a miracle cure.
Should You Always Soak Rhubarb Before Making Pie?
No.
You don’t have to.
Plenty of excellent rhubarb pies are made with fresh rhubarb that has simply been washed, trimmed, chopped, and combined with sugar.
The salt-water soak is more of an optional experiment.
If your rhubarb tastes pleasant and tart rather than harshly bitter, there may be little reason to soak it.
And if you’re following a specific recipe, it’s usually best to follow the recipe rather than adding an untested soaking step.
What About Soaking Rhubarb in Plain Water?
Plain cold water can also help remove some surface compounds and can keep cut rhubarb crisp.
But without salt, you don’t get the same flavor-balancing effect that a salted soak may provide.
If you’re specifically trying to reduce a bitter edge, a lightly salted soak is the more interesting experiment.
Just remember to rinse and drain the stalks thoroughly afterward.
Could You Soak Rhubarb for Several Hours?
I wouldn’t make a long soak my default method.
The longer the rhubarb sits in water, the more opportunity there is for water-soluble flavor compounds to move out of the cut surfaces.
You could also end up with waterlogged pieces.
A short soak is enough for an experiment like this.
Thirty minutes is a reasonable starting point.
There’s no obvious benefit to leaving your rhubarb submerged all day before making a pie.
What If the Rhubarb Is Extremely Bitter?
If the rhubarb tastes unusually unpleasant, don’t assume that a longer salt-water soak will solve everything.
Instead, inspect the stalks.
Make sure the leaves have been completely removed.
Look for stalks that are damaged, deteriorating, or otherwise abnormal.
Fresh rhubarb should generally be firm and crisp.
If something looks rotten or smells off, don’t try to fix it with salt water.
Discard questionable produce.
Food preparation techniques can improve the flavor of good ingredients, but they can’t turn spoiled food into safe food.
Does Red Rhubarb Taste Sweeter Than Green Rhubarb?
This is another common assumption.
The color of rhubarb stalks doesn’t reliably tell you how sweet they will taste.
Some varieties naturally produce redder stalks, while others are greener.
Rhubarb can be very tart regardless of whether the stalk is predominantly red or green.
So don’t choose rhubarb solely because the stalks are bright red.
Look for firm, fresh stalks with good color and no obvious deterioration.
How to Prepare Rhubarb Safely
Before you begin, follow a few basic steps.
Remove the leaves
Cut off and discard the leaves completely.
Wash the stalks
Rinse the stalks under clean running water.
Trim the ends
Remove any dried or damaged portions.
Check for spoilage
Discard stalks that are moldy, slimy, rotten, or otherwise spoiled.
Cut the stalks
Slice them according to your recipe.
Soak if desired
If you’re experimenting with a salt-water soak, keep it brief and cold.
Drain thoroughly
Don’t carry excess soaking water into your pie filling.
A Few Ways to Balance Tart Rhubarb
If you’re making a pie and the rhubarb is especially tart, there are several ways to balance the flavor.
Pair it with strawberries
This is a classic combination for a reason.
Add vanilla
Vanilla adds warmth and makes the filling taste more rounded.
Use citrus carefully
A little lemon or orange zest can brighten the filling, although adding a lot of acidic juice may make an already-tart filling even sharper.
Add enough sugar
Sugar is the traditional counterbalance to rhubarb’s acidity.
Add a pinch of salt
Even in the final pie filling, a small amount of salt can help balance sweetness and acidity.
Use a thickener
Cornstarch or another appropriate pie thickener can help control the juices released during baking.
The Biggest Mistake: Adding the Wet Rhubarb Straight to the Pie
If you decide to try the salt-water soak, don’t skip the draining step.
This is especially important for pie.
A wet filling can contribute to a soggy bottom crust.
After soaking, drain the rhubarb thoroughly.
You can even spread it briefly on a clean towel or paper towel to remove excess surface moisture.
You don’t need to squeeze the rhubarb aggressively.
Just remove the extra water.
What I Would Do Next Time
After trying this experiment, I would make a few small changes.
I’d keep the water very cold.
I’d use a relatively mild amount of salt rather than making an extremely salty solution.
I’d keep the soaking time around 30 minutes.
I’d rinse the rhubarb afterward.
And I’d drain it very thoroughly before mixing it into the pie filling.
Most importantly, I’d taste the rhubarb before and after the soak.
That’s the easiest way to determine whether the technique actually makes a noticeable difference with the particular rhubarb you’re using.
Frequently Asked Questions
Does soaking rhubarb in salt water remove bitterness?
It may reduce the perception of some bitter or harsh flavors, but it doesn’t eliminate rhubarb’s natural tartness. The effect can vary depending on the rhubarb and the soaking conditions.
Does rhubarb need to be soaked before making pie?
No. It’s completely optional. Many recipes use fresh rhubarb directly after washing and chopping.
How long should rhubarb soak in salt water?
For an experiment like this, about 30 minutes is a reasonable short soaking period. Longer soaking isn’t necessarily better.
Should the water be cold?
Cold water helps keep the cut rhubarb crisp while it soaks. Using ice-cold water is fine.
Should I rinse rhubarb after soaking it in salt water?
Yes. Rinsing removes excess salt from the surface before you use the rhubarb in your recipe.
Does soaking make rhubarb sweet?
No. Rhubarb will remain naturally tart. Sugar or sweet fruit is still needed to balance the flavor in most dessert recipes.
Can I eat rhubarb leaves?
No. Rhubarb leaves should not be eaten. Remove and discard them, using only the stalks for culinary purposes.
Does soaking rhubarb make it less acidic?
Don’t think of the technique as completely removing rhubarb’s acidity. A short soak may alter the flavor of the cut surface, but the stalk will remain characteristically tart.
Can I use this trick for rhubarb crisp or crumble?
Yes. If you like the result, the same preparation could be used before making a rhubarb crisp, crumble, compote, or other cooked rhubarb dessert.
The Bottom Line
Thirty minutes in ice-cold salt water didn’t magically turn my bitter spring rhubarb into sweet fruit.
And honestly, I wouldn’t want it to.
Rhubarb’s tartness is what makes it special.
What the short soak appeared to do was soften some of the harshness of the raw stalks while keeping them crisp before cooking.
The finished pie still tasted unmistakably like rhubarb.
It was tart, sweet, bright, and balanced.
The biggest lesson is that you don’t necessarily need to fight rhubarb’s natural flavor.
Instead, you can learn how to balance it.
If your spring rhubarb tastes particularly harsh, a short soak in cold, lightly salted water is an interesting old-fashioned kitchen experiment.
Just remember the important basics:
Use the stalks, never the leaves. Keep the soak short. Rinse away excess salt. Drain the rhubarb thoroughly. And don’t expect salt water to replace the sugar that normally balances rhubarb’s natural tartness.
Sometimes the best kitchen tricks aren’t about completely changing an ingredient.
They’re about taking one of its strongest characteristics and making it work in your favor.
And in this case, that meant taking an aggressively tart spring vegetable and turning it into the star of a wonderfully balanced pie.