Begin by washing your cranberries and removing any soft or mushy cranberries. Chop them roughly and place them in a pot.

Add the water and the cup of sugar to the pot. Bring the cranberries to a simmer over medium heat, then reduce the heat to medium low. Continue to gently simmer for 10-12 minutes, or until all of the cranberries are soft and can be mashed.

Place a fine sieve over a bowl and press the cranberries to remove all of the juice. Some pulp may collect along the bottom of the sieve–make sure to scrape it off and add it to the bowl. Allow the cranberry juice mixture to cool slightly.

Separate the eggs and place the yolks in a bowl. Beat them until smooth, then slowly drizzle them into the cranberry juices and pulp while whisking quickly. You don’t want the eggs to cook too quickly and be scrambled.

Clean out the sieve and place it back over the bowl.

Add the mixture back to the pot and heat it over medium low heat, stirring constantly, until you see bubbles beginning to form on the surface of the curd. Cook it for one minute while stirring briskly, then remove it from the heat.

Pour the curd through the sieve. Use the spoon to stir it through the sieve into the bowl. Add the butter and whisk it in until it’s all melted.

Place the curd in a clean jar and chill it until completely cold. Store it in the refrigerator.