Combine the egg/yolks, sugar, juice, zest, and wine in a bowl
Cook over a water bath stirring constantly until mixture starts to thicken 7-10 minutes
When the curd sticks to the back of a spoon its ready
Remove bowl from heat and stir in butter one cube at a time till all blended
Transfer to a clean bowl and cover with plastic wrap, making sure to have plastic in contact with the curd. This will stop a skin from forming.
Cool in fridge
Once cool transfer to clean glass jars and store in fridge up to 3 months