Romaine lettuce is commonly used for maror. This type of lettuce is known as an open leaf variety, meaning that as the leaves sprout forth from the ground, they begin to open up like a flower. Toward the end of their growth, the leaves begin to close around the stalk. Since romaine lettuce grows open, it is much more prone to insect infestation throughout the head than other varieties that primarily grow as a closed ball.
The insects most commonly found in open leaf lettuce are small black or green aphids and thrips. The leaves of the vegetable often camouflage these insects. The open structure of these vegetables allows insects to penetrate the entire head. Often, insects may be found between the innermost layers of leaves of an infested head.
Therefore, each leaf must be washed and checked individually. The use of a light box for checking lettuce can be extremely convenient and helpful. However, even if a light box is not used it is crucial to examine both sides of each leaf against a good source of light.
Occasionally, worms may be found in burrows within the body of the leaf. Look for a narrow translucent burrow speckled with black dots breaking up the deep green color of the leaf. These burrows will often trap the worm within the leaf. To rid the leaf of these worms, carefully slit the bumpy part within the burrow with a sharp knife and remove the worm. It is important to note that many of these varieties feature curly leaves with many folds in which the insects tend to hide. It is therefore recommended that they be washed and checked with extreme caution.
These two options for properly checking romaine lettuce, using a light box or a mesh cloth, are equally acceptable.
1. Cut off the lettuce base and separate the leaves from one another.
2. Soak leaves in a solution of cold water and soap. The proper amount of soap has been added when some bubbles are observed in the water.
3. Agitate lettuce leaves in the soapy solution.
4. Spread each leaf, taking care to expose all its curls and crevices. Using a heavy stream of water or sink hose, remove all foreign matter and soap from both sides of each leaf. Alternatively, a vegetable brush may be used on both sides of the leaf.
5. Leaves should be checked over a light box or against strong overhead lighting to verify that the washing procedure has been effective. Pay careful attention to the folds and crevices in the leaf where insects have been known to hold tightly through several washings.
Mesh Cloth (washing lettuce and checking water)
1. Agitate and soak leafy produce for a few minutes in cold water containing vegetable wash.
2. Drain the water through a mesh cloth placed between two large strainers.
3. After draining the water, place the mesh cloth on a light box to inspect for any possible insects that were dislodged from the produce into the water. The mesh cloth method of checking has become increasingly popular and can be a time saver, making it easier to check larger volumes of produce.