Helen's lemon curd

1. Gratei rind of lemons, then, squeeze lemons.
2. Melt butter in top of double boiler.
3. Add juices and rind.
4. Stiri over hot water until sugar dissolves.
5. Beat eggs lightly and add to butter mixture.
6. Cook over simmering water, stirring constantly til thick.
7. Ladle into jars and process in boiling water for 10 minutes (opt).
8. Or refrigerate.