The Egg Float Test: How to Check Whether Your Eggs Are Fresh
雞蛋新不新鮮？用一碗水就知道！
科普園地
by Mark Darvill
The egg is a natural ready-made package of protein, vitamins, and minerals. Not only are they delicious and extremely versatile, but they also offer a variety of health benefits. However, just like any other food that has the propensity to spoil, there are inherent dangers with eggs as well. Anyone who’s ever eaten a “bad egg” has learned the hard way if an egg has been left in the fridge for too long. In fact, egg shells have very tiny pores, so the fluid inside an egg can evaporate and the outside air can get in. This will enlarge the air pocket within the shell. As an egg ages, the air pocket grows in size, the egg white becomes increasingly thinner, and the quality of the egg thus diminishes. Eventually, such an egg will develop mold or bacteria, making it unsafe to eat.
Fortunately, these air pockets give us an ideal method for testing whether an egg is still fresh. Performing this test, known as the “Egg Float Test,” couldn’t be easier; simply fill a bowl with water and place your egg inside. An egg that sinks is still fresh. If the egg falls over onto its side at the bottom, it is still of prime freshness, whereas an egg that sinks but stands upright should be eaten fairly soon.
If the egg floats, it is because the air pockets inside it have grown to a certain size, and thus the egg is no longer fresh. Such an egg is not necessarily unsafe to eat, but you should conduct further tests to check its safety before consuming it. For example, you could crack open one of the eggs in your batch and give it a sniff. There’s no mistaking a bad or rotten egg because the smell is pretty distinctive. The sulfuric odor is a dead giveaway that the egg is no longer suitable for consumption.
1. Which of the following can be inferred from the passage about a rotten egg?
(A) The contents of the egg decrease over time.
(B) It doesn’t have protein, vitamins, and minerals anymore.
(C) Whether an egg is rotten can be determined by the float test alone.
(D) The egg white of a rotten egg is less likely to flow than that of a fresh one.
2. According to the passage, which egg is most likely unsafe to eat?
