1. Add the strawberries and sugar to a large pot and stir to coat well, and place over medium high heat. Stir the berries and sugar occasionally until the mixture comes to a boil. Add the lemon juice and zest.
2. Continue to maintain a rolling boil that cannot be stirred down for about 30 minutes, or until the jam reaches 220 degrees. Remove from the heat and stir in the butter. This will remove the rest of the foam and give the jam a nice shine.

If canning

1. Fill hot, clean half pint or pint size jars with ¼ inch of headspace. Make sure the rims are clean before placing a lid on each jar. Secure lids with bands until fingertip tight. Process in boiling water bath for 10 minutes (half pint jars) or 15 minutes (pint jars). Remove from canner and allow seals to pop down. This can take several hours, don’t worry if they don’t pop immediately. Canned jam may be stored indefinitely (check for freshness before using).

If refrigerating

1. Add finished jam to either jars or other storage containers, and seal. Jam may be refrigerated for 3-4 weeks.

If freezing

1. Jam may be stored frozen for a year.