How to Choose Fresh and High-Quality Balut (Fertilized Duck Eggs)

If you want to know how to pick a fresh balut that is not too mature, keep these simple tips in mind.

Balut, or fertilized duck eggs, is a highly nutritious food that is loved by many. From this ingredient, you can prepare a variety of dishes such as boiled balut, balut grilled with scallion oil or tamarind sauce, and balut cooked with mugwort leaves. Each preparation brings out a unique flavor while maintaining the egg’s rich nutritional value.

One of the most important factors people consider when buying balut is how to select fresh eggs that are not overdeveloped. Older balut eggs contain more developed embryos, with longer feathers, which many people find unappetizing. In contrast, younger balut eggs have soft, less developed embryos and are easier and more enjoyable to eat.

Here are some practical tips to help you choose high-quality balut eggs:

Examine the Shell

Fresh, young balut eggs usually have slightly rough shells and may even be covered with a thin white powdery layer.

By holding the egg up to a light source—such as under a lamp—you can see that the air space at the larger end is small, without dark spots or cloudy areas.

Older balut eggs typically have smooth shells that may appear slightly grayish. When viewed under a strong light, these eggs often have a larger air space at one end, and small dark spots can be seen inside the egg.

Shake the Egg Gently

In a fresh balut egg, both the egg white and yolk are dense, so shaking it gently should not produce any noticeable sound.

In older eggs, however, the embryo is more developed, leaving a larger air space at the top. Shaking these eggs will produce a distinct sound of liquid movement.

If you prefer slightly more developed balut, select eggs with a larger air space. For younger eggs, choose ones that feel fuller and have a smaller air pocket.

Check the Weight

The simplest way to distinguish a fresh balut egg from an older one is to hold it in your hand.

Eggs that feel heavy and firm are usually young, containing plenty of egg white and yolk. Lighter eggs are often older, with more developed embryos and less yolk.

A practical tip is to hold two eggs of similar size in both hands. The heavier egg is likely fresher, while the lighter one is older. This technique is very reliable, especially if you want to enjoy the softer texture of a young balut.

Use Salt Water to Test Freshness

To determine whether a balut egg is fresh or old, place it in a glass of lightly salted water. Fresh eggs will sink to the bottom, while older eggs will float. This method can also be applied to regular duck or chicken eggs.

Balut eggs do not keep as long as regular duck or chicken eggs. It is best to cook and consume them as soon as possible. If stored for 2–3 days, the yolk may become hard, and the egg will lose some of its desirable texture and flavor.

Storage Tips

For raw balut eggs, keep them in a warm place to allow the embryo to remain viable. They can typically be stored for 1–5 days. Eggs stored longer may become overdeveloped, resulting in a more feathered embryo.

For cooked balut eggs, refrigerate them within two hours of boiling. Store the eggs in a sealed container to maintain freshness. Reheat before eating if needed. However, for the best taste and texture, it is recommended to consume balut immediately after cooking.

Candling: Observing the Egg Under Light

When buying balut, hold the egg up to a bright light to observe the internal air space.

A large air pocket indicates an older egg, while a small air pocket suggests a younger egg. You can also assess freshness by observing the embryo: a healthy, fresh embryo appears pinkish and solid, with clear red veins spread evenly.

In contrast, if the embryo moves too freely or the veins appear faint and weak, the egg may be spoiled and should be avoided.