Why is Celery Bitter (And How to Fix It)

There is nothing worse than going to all the effort of growing what should be delicious organic celery only to find it is bitter and horrible. There are five main reasons why celery becomes overly bitter. Read on to find out what causes celery to become bitter and how you can ensure your celery crop is crisp and tasty. And if you do end up with bitter celery by growing it or purchasing bitter celery, find out how you can reduce the bitterness to use it in a dish.

Why is Celery Bitter and How to Fix it - Bunch of Celery

The main reasons why celery becomes bitter are due to a lack of nutrients while the plant is growing, a lack of water, too much heat, too much sun, or the celery plant has over matured and is now too old.

So let’s find out exactly what each reason is and how we can take steps to avoid growing bitter celery.

Why Celery Tastes Bitter

1. Celery Plant Lack of Nutrients

A lack of nutrients as the celery plant is growing is the most common cause of bitterness. As with all vegetable plants, the healthier they are, the better they will taste. A plant that is struggling, for whatever reason, will produce tasteless or bitter vegetables.

Celery needs more nutrients than most plants to thrive but it is definitely worth the effort to ensure sweet stalks. Before planting your celery, you should prepare the bed by digging in some aged manure and compost. Manure should not be too fresh as this can burn the vegetables. If you live in a climate with milder winters, you can dig manure and compost into the soil in the winter. Winter is usually a quiet time in the garden and it will save time in the spring when things become busy. It also gives the manure a chance to settle before planting in the spring.

Once your celery is growing, it needs to be fed every 3 to 4 weeks. You can use compost, aged manure or a store bought fertilizer such as this organic edible plant fertilizer. Any fertilizer that is designed for vegetables can be used. A mixed fertilizer is good to start with but you can use a nitrogen only fertilizer for the later feeds as celery has a shallow root system.

2. Lack of Water for the Celery Plant

There is nothing like a lack of water to stress celery plants and a stressed plant is a bitter plant. Celery needs one to one and a half inches of water per week.

Some plants, such as strawberries, like one good soaking per week but celery prefers regular watering. I water my celery plants every second day during warm weather. If you have a particularly hot and windy day, you might need to give an extra watering.

The soil should feel slightly damp when you push your finger into it. Celery likes soil that drains well. Soil that drains well should allow all the water to soak away quickly. You should not see any water lying around an hour after watering.  

3. Celery Plant Receives Too Much Heat

Celery likes to grow in the sun but it does not like excessive heat. Excessive heat will cause your celery to become bitter. Celery likes a moderate temperature of between 60 and 70 degrees F (15.5-21C).

If you see the temperature is going to exceed this, there are steps you can take to protect your celery. Watering plants in the morning helps to keep the soil cool for the rest of the day.

You can also put mulch on the plants to keep the coolness in and the heat out. You can put up some form of shade to protect the plants during the hottest time of day.

Make sure whatever you are using to shade the celery plants does not touch the plants directly. Shade cloth can be erected as a permanent structure. For a less permanent solution, you can put up a beach umbrella.

If you live in a very hot area, it may be better to plant your celery in the early spring and autumn and not in the summer. In areas that have frosty winters and sweltering summers plant your seeds indoors in the late winter and plant the seedlings out straight after the last frost.

This will give your celery plants a chance to grow in the cool spring before the extreme summer temperatures arrive.

4. Celery Plants Receive Too Much Sun

The lighter the color of the celery stalk the sweeter it will be. To make your stalks lighter you need to hide them from the sun so that they stop photosynthesizing and producing chlorophyll. It is the abundance of chlorophyll that makes the celery taste bitter.

Shading the stalks from the sun is called blanching.

To blanch your celery you need to cover the stalks with something that allows air in but not sunlight. Paper rolled into cylinders or small cardboard boxes work well.

You can also mound soil up around the stalks leaving only the leaves sticking out. This will make cleaning the celery a little more difficult but works well. You should cover the stalks but not the leaves.

The leaves will then continue to photosynthesize and feed the plant. Blanch the stalks 10 to 14 days before you want to harvest them.

Blanched celery may be less bitter but it also has less flavor and less nutrients than unblanched celery.

5. Celery Plant is Too Old

Even if you have done everything correctly, an old celery stalk will be woody and bitter.

Celery takes 130 -140 days to grow from germination to maturation. Keep a note of when seeds germinated as this will give you a good idea when to harvest.

Another way to tell when celery is ready is to measure the stalks. When the stalks have reached 6 inches (15cm) in length from the base to the first leaf they are ready to harvest.

Why is Celery Bitter and How to Fix it - Freshly Havested Celery

How to Make Celery Less Bitter

What do you do if you’ve already grown bitter celery or perhaps you’ve bought a crisp-looking bunch of celery only to find it is bitter?

The lighter in color the stalks are, the sweet and milder the flavor. Therefore, if you have a bitter bunch of celery use the pale inner stalks in recipes that require raw celery such as salads and smoothies.

Celery leaves are more bitter than the stalks so you may not want to use the leaves of a bitter bunch.

The outer stalks will need to be cooked to minimize the bitterness. Cooking also brings out the peppery flavor and adds an aromatic quality to your dish.  

Sautéing Bitter Celery

Sautéing finely sliced celery in butter will soften the texture and flavor while still retaining some of the crunch. This can then be used in stir-fries and stuffings.

Boiling Bitter Celery

Boiling celery will reduce its bitterness. This is ideal for soups and stews where the pepperiness will come through but the bitterness will be masked.

Steaming Bitter Celery

Steaming celery will also reduce the bitterness and enhance the aromatic flavor.

Pairing Flavors to Reduce Bitter Celery

Another way to mask the bitterness of celery is to pair it with strong-tasting foods such as onions and garlic. Rich, meaty soups and stews will carry the bitterness well. Soy sauce is a good ingredient to pair with bitter celery as it is very salty and has a strong flavor.

Acidic foods, such as tomatoes, will also mask the bitterness.

Blanching in Bitter Celery in Salt Water

Some people believe that blanching bitter celery in saltwater can reduce some of the bitterness. This may be true as salt blocks some of our taste receptors. It is unlikely that the salt has any effect on the plant’s bitterness but rather on our taste buds.

How to Avoid Buying Bitter Celery

What Makes Celery Bitter and How to Fix it

The darker the green of the celery the more bitter it will be. So when buying celery look for the lightest bunch. You also want to find the youngest bunch as old celery stalks can be woody and bitter. Look for bunches that are smaller, shorter, and have crisp, fresh leaves. This should ensure that the celery bunch is young and fresh.

When is Celery Too Far Gone?

You can tell if celery has been in the ground too long by its size. Celery should be harvested when the stalks are 6 inches (15cm) long from the base to the first leaf. If the stalks are longer than 6 inches they will most likely be woody, stringy, and bitter.

You will know that celery is not fresh if the leaves are wilted or browning around the edges. The stalks can still be eaten but I wouldn’t buy a bunch in this condition. To tell if the stalks are becoming too old feel them. As they get older, they lose their crispiness and start becoming pliable and bendy. Old stalks start to move away from the heart of the celery as they become limp.

Is Bitter Celery Safe to Eat?

Bitter celery is safe to eat and may even contain more nutrients than sweeter, milder bunches. Pale celery has less chlorophyll and nutrients but also less bitterness. Pale celery is still packed with nutrients so if you don’t like the bitterness, avoid it.

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Further reading:

Why is Celery Bitter and How to Fix it