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Green Walnuts: Safety, Nutrition Facts and How To Use Them

In this article, we will discuss the difference between a green and a regular walnut, the nutritional profile of green walnuts, their common use, and much more.
Draga Neskovic, BA Philosophy, Adult Education

Written by Draga Neskovic, BA Philosophy, Adult Education. Updated on December 12, 2022.

Just like any other nut, walnuts have numerous health benefits and provide us with so many vitamins, minerals, antioxidants, and nutrients that our body requires.

They are the perfect plant-based snack. When you are in a hurry, a handful of walnuts (or any other nut) helps restore your energy and keeps you full until your next meal.

Although all types of nuts have a wide variety of health benefits, walnuts are often considered the healthiest of them all.

If you have wondered what exactly green walnuts are, you are in the right place.

In this article, we will discuss the difference between a green and a regular walnut, the nutritional profile of green walnuts, their common use, and much more.

What Are Green Walnuts?

Green Walnuts are potential walnuts that are harvested before having a chance to fully ripen.

The name originates from the color of the nutshell, which distinguishes a ripe walnut from an unripe one.

Once the walnuts are mature their shell becomes yellowish and the nut hardens (both the shell and the inside of the walnut).

If you harvest the fruit of a walnut tree before this happens, it will have the color of lime with tiny white spots.

The inside of a green walnut is white and has a gelatin-like texture. It has a citrusy aroma.

The taste is bitter and spicy. It is not very tasty when eaten raw, but the unique flavor makes it a great ingredient for cooking and experimenting with recipes.

They are harvested in May, June, or July, depending on the geographical area and the climate.

You can harvest them directly from the tree or collect the fallen walnuts from the ground. Some argue that the latter has been rejected by the tree and thus should not be picked by humans either.

The important thing is to wear gloves when you are picking them, to avoid stains from the juices.

The interesting history of this food goes a long way and has an essential role in an ancient Celtic custom.

In short, every summer solstice barefoot virgins would harvest unripe walnuts. This practice symbolized defeating evil and the darkest of nights thanks to pure souls who have been harvesting young, green fruit when the light was strongest.

Green walnuts are not only used in various recipes but as a medicine as well thanks to their positive impact on human health.

Are Green Walnuts Poisonous?

It is perfectly safe for most people to consume and harvest both ripe and unripe walnuts.

Green walnuts, just like ripe walnuts, are a type of nut, so if you are allergic to nuts, do not eat them.

Green walnuts are not poisonous.

However, they can be harmful to people whose bodies contain high levels of iodine.

Iodine is a crucial mineral for the functioning of the thyroid. Iodine deficiency leads to thyroid disorders and symptoms such as an enlarged thyroid gland, fatigue, weight gain, etc.

Not enough iodine in a person’s body is a common problem. On the other hand, too much of it—a phenomenon called iodine-induced hyperthyroidism, is a relatively rare issue.

However, that does not mean it should be overlooked. Both excess and deficiency of iodine have similar symptoms and cause harm to our health.

Since green walnuts are rich in iodine, people with an excess of iodine in their bodies should avoid them.

There have also been some suggestions that green walnuts may negatively impact those who suffer from gastritis. So it would be best to check with your gastroenterologist if you can consume this food safely.

In conclusion, you can eat green walnuts, but be careful when it comes to your iodine levels and severe stomach issues.

Green Walnuts Nutritional Facts

Green walnuts are rich in vitamins such as vitamin C, vitamins B1, B2, B3, B8, vitamin E, and minerals such as iron, magnesium, potassium, calcium, among others.

They have higher levels of antioxidants compared to other nuts. Antioxidants reduce the effect of free radicals, which helps prevent diseases such as cancer and heart failure.

Green (and regular) walnuts are a source of omega-3 fatty acids, and also contain more of it than any other nut.

They contain an essential fat (which means human bodies are not able to produce them, so they have to be acquired through food) called alpha-linolenic acid which may decrease the risk of heart disease.

Walnuts are a source of polyunsaturated fats (the good kind unlike saturated fats) and can help lower cholesterol and keep the artery walls clean.

One ounce of these nuts (about 7 walnuts) contains approximately 185 calories, 4 grams of protein, carbohydrates and fats, and 2g of fiber.

Green walnuts are a high-calorie food, but they will keep you full for a long time, and their health benefits are immense.

So, if you are not on a strict calorie-deficit diet, you can snack on these nuts guilt-free knowing that it increases your overall health.

What to Do With Green Walnuts?

Except for consumption, the oil of the walnut is also used as dye thanks to its strong color (that is why it is important to wear gloves while harvesting).

It is safe to eat raw green walnuts, but the taste isn’t quite satisfying.

On the other hand, that same unique taste makes these nuts extremely suitable for a wide variety of recipes.

A lot of traditional uses for this unripe nut contain some amount of alcohol and sugar (which do not make them as healthy as they originally are) or honey (which does not make them vegan).

Some of these recipes include the Italian liqueur called Nocino, French wine Vin de Niox, Italian syrup Sciroppo di Noci Verdi, green walnut ketchup and jam, etc.

In this section, we will focus exclusively on healthy and plant-based variations of green walnuts.

So, here is the best healthy and tasty recipe for unripe walnuts—pickled green walnuts.

Pickled Green Walnuts

Green walnuts are sometimes referred to as the ‘King of Pickles,’ but the recipe for pickled walnuts is actually quite underestimated and unknown.

They are most popular in Britain, and rarely consumed in other parts of the world.

The process of making them is easy, although it requires some time.

The walnuts need time to brine before they are ready for pickling in vinegar. The most common spices added to this unique recipe are ginger, salt, pepper, garlic, and horseradish.

Traditionally, they are used as an addition to dishes with meat, cheese, and other animal products.

Nevertheless, they are a perfect vegan snack packed with so many important nutrients.

How to Ripen Green Walnuts?

Walnuts can not be ripened if they were harvested while they were green and immature.

The only way to ripen green walnuts is to let them develop on the tree until they are fully mature.

So, unfortunately, you can not ripen green walnuts by yourself.

But there are a variety of ways you can use them, including cooking, medicine, etc.

If you specifically need mature walnuts, just harvest them or buy them once they are ripe. As we said, the color and consistency help us easily distinguish regular from green walnuts.


Green walnuts are walnuts that have been harvested before having the chance to fully ripen.

There is no other way to ripen them except to not pick them from a tree until they are mature.

A mature walnut is different from a green one by its color (yellow) and texture (both the shell and the inside of the nut are much harder than the syrupy consistency of the unripe nut).

They are harvested in the summer, unlike ripe walnuts that should be picked in autumn.

Just like ripe walnuts, green walnuts are extremely healthy.

They are packed with vitamins, minerals, antioxidants, and omega-3 fatty acids (the essential alpha-linolenic acid (ALA) fatty acid).

They are high in calories, but also contain a fair amount of protein, fats, and carbs.

Green walnuts are not poisonous.

That being said, you should be very careful when consuming these nuts if your body contains a lot of iodine since green walnuts are high in iodine.

If you have some severe stomach issues, consult your doctor about the foods you can safely consume.

Also, if you have a nut allergy, do not eat green walnuts, or any other nuts.

They can be eaten raw, but the taste can be a bit off-putting.

One of the best uses and recipes for this food is pickled green walnuts.

It is a traditionally British recipe used as a side dish for meals containing animal products. But it has evolved into a relatively popular, easy, and nutritionally dense vegan snack.

This nut has been a hidden gem in the world of nutrition for too long. Luckily, its beneficial health impact and unique taste are becoming more visible every day.

So, if you come across a walnut tree with unripe fruits next summer, do not think you are in the right place at the wrong time. The time is perfect for harvesting green walnuts.

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