The bitter herbs are eaten once after the matzah (step 9 of the Seder), and then again with matzah in the Korech sandwich (step 10).
How much bitter herbs should one eat each time? Three-quarters of an ounce (a little more than 7 grams).
Either of two different types of bitter herbs may be used at the Seder, individually or in combination:
- Peeled and grated raw horseradish.
- Romaine lettuce. [Some suggest that the stalks be used rather than the leafy parts, because of the difficulty in properly examining and ridding the leafy parts of commonly present tiny insects.] Three-quarters of an ounce of stalks covers an area 3" x 5".