Pear lime marmalade

5-1/2 C pears, peeled, cored, and chopped
1 T lime zest (about 2 limes)
1/3 C lime juice (about 2 limes)
2 1/3 C sugar
1 T grated ginger (optional)

Place all ingredients in a large stainless steel or enamel saucepan. Bring to a boil, stirring constantly. Cook until it reaches the gel stage, around 15 min. Ladle into sterile hot jars, leaving 1/4-inch head space. Seal and process.