How Humidity-Controlled Crisper Drawers Work

A humidity-controlled crisper drawer uses a slider to open or close a small vent, which decides whether moisture from your produce stays in the drawer or escapes into the fridge. Closed keeps the air damp for leafy greens; open lets moisture and ripening gas out for fruit. Using the right setting keeps produce fresh longer, and a few drawer problems explain wilting or frozen vegetables.

How it works, step by step

1. The drawer is a nearly closed box. It sits below the shelves, shielded from the cold air that blows through the rest of the fridge.
2. Produce gives off moisture. Fruits and vegetables keep releasing water vapor after they are picked, and that moisture builds up inside the drawer.
3. The slider moves a vent. Whirlpool's guide to crisper drawer settings explains that the drawer works by controlling the airflow that enters and leaves the bin.
4. Closed means high humidity. With the vent shut, the moisture stays in, which keeps thin-skinned vegetables that wilt easily crisp. Whirlpool lists broccoli, cucumbers, lettuce and leafy greens.
5. Open means low humidity. With the vent open, moisture and air escape. Many fruits release ethylene gas as they ripen, and the open vent lets it out, which slows ripening and rot. Whirlpool lists apples, pears and melons, and notes that mushrooms also keep longer in a drier drawer.
6. Some sliders are labeled with produce instead of high and low, so you set the drawer by what you are storing.

What you'll notice because of it

• Light condensation inside a high-humidity drawer. Some moisture on the drawer walls is expected when the vent is closed.
• Greens that stay crisp for longer in the closed drawer than on an open shelf.
• Fruit that ripens more slowly in the open drawer.
• No temperature change. The slider controls moisture, not temperature. Some refrigerators have a separate temperature-controlled drawer, which is a different feature.

Where it can go wrong

A slider or vent that is stuck or broken

Symptom: greens wilt quickly even on high, or fruit turns soft and moldy even on low, because the vent is not doing what the slider says.

Water pooling in the drawer

Symptom: standing water under the produce. Heavy condensation can cause this on high settings, but a puddle that returns after you dry the drawer often comes from a blocked defrost drain dripping into the cabinet.

Produce freezing

Symptom: frozen lettuce or icy edges on vegetables. Whirlpool suggests checking that the fridge is set to the right temperature. A drawer sitting under a cold-air vent, or a fridge running colder than its setting, can also freeze produce.

An overpacked drawer

Symptom: faster rot and uneven freshness. Whirlpool warns that packing a crisper too tightly can block the vents.

Getting the most out of it

• Use one drawer for vegetables on high and one for fruit on low, rather than mixing them.
• Keep ethylene-producing fruit like apples away from leafy greens.
• Leave some room in each drawer for air to move.
• Wipe the drawers out regularly and dry them before refilling.
• Remember that not all produce needs the fridge; Whirlpool notes some keeps better outside it.

Frozen lettuce or a drawer that keeps filling with water points past the slider to the refrigerator itself, such as its temperature control or defrost drain, and a refrigerator service visit can trace it. How humid the drawer can get also depends on the cooling layout: fridges with separate fresh-food cooling keep moister air overall, as how a dual-evaporator refrigerator works explains.

Sources

• Whirlpool: What crisper drawer settings should you use?

Worth knowing: The crisper slider controls moisture, not temperature, so frozen produce points to the fridge's cooling, not the drawer setting.

If your crisper drawers keep freezing produce or collecting water, call ProFix Miami at (786) 723-6874 to have the refrigerator checked.