How to check red cabbage for bugs

Does it need checking? Red cabbage is sometimes infested in the USA and mostly infested in Israel. (Rav Moshe Vaya) Separate the leaves, soak them in soapy water, then check the water for bugs.

Rav Vaya’s rating

USA	★	sometimes infested (mi’ut hamatzui)
Israel	★★	mostly infested (muchzak b’negiut)

Rav Moshe Vaya, Bedikat HaMazon K’Halacha, Degree of Infestation chart, p. 937 (Red Cabbage)

Which bugs

Small bugs that come off the leaves and float in the soaking water.
OU Kosher’s chart names them for red cabbage (same as green cabbage): thrips or cabbageworms.

How to check

Separate the leaves. It is best to take off all the leaves. At the least, take off the seven outer leaves.
Soak the separated leaves for a few minutes in water with a little soap. Agitate them.
Move the leaves to clean water with no soap. Agitate them again while the leaves are separated in the water.
Take the leaves out and check the water for bugs. Small bugs may be floating in it.
With nothing left in the water, look closely at the water to see if there are any bugs.

Watch

▶ How to Clean Cabbage

Pictures

A hand moves the separated cabbage pieces around in the soaking tub. (“How to Clean Cabbage”, 0:28)

Sources

Rav Moshe Vaya, Bedikat HaMazon K’Halacha, Degree of Infestation chart, p. 937 (rating).
OU Kosher: same as green cabbage: thrips or cabbageworms, most often in the outermost six leaves. Discard the loose leaves, core the cabbage and split the head in half. Peel 3 layers and check these 6 leaves on both sides under direct light. If 1–2 insects are found, check another layer. If the last three layers in a row were clean and the remaining leaves are tightly packed, the rest may be used without checking, after washing well. If 3 or more insects are found, wash and check the remaining leaves. (Fruit and Vegetable Inspection Chart)
cRc: remove the outer 4 leaves. Rinse the remaining leaves well, front and back, under a stream of water. Pre-washed red cabbage needs no further washing. (Fruits & Vegetables Checking Guide)

References: OU Kosher — Fruit and Vegetable Inspection Chart (PDF) · cRc — Fruits & Vegetables Checking Guide