Recipe information
Yield
Makes about 4 1/2 cups
Ingredients
Preparation
Step 1
Working on large plate to catch juice, cut lemons in half lengthwise, then very thinly crosswise. Discard seeds. Pack enough lemons and any juice to measure 2 1/2 cups. Transfer to large nonreactive pot. Add 5 cups water; bring to boil. Reduce heat to medium; simmer 10 minutes. Remove from heat; let stand uncovered overnight.
Step 2
Measure lemon mixture (there should be about 5 1/2 cups). Return to same pot. Add equal amount of sugar (about 5 1/2 cups). Scrape in seeds from vanilla bean; add bean. Add pinch of salt. Bring to boil, stirring until sugar dissolves. Attach clip-on candy thermometer. Maintaining active boil and adjusting heat to prevent boiling over, cook until temperature reaches 230°F, stirring occasionally, about 30 minutes. Cool to room temperature. Transfer to jars. Cover and chill. (Can be made 2 weeks ahead. Keep refrigerated. Bring to room temperature before serving.)
