Bring water to a boil in a large pot. Then add the sugar to the boiling water and stir until dissolved and becomes sugar water.
Add the raspberries and stir in. Bring back to a boil and then turn the heat to low or simmer and cook for 20 minutes, stirring occasionally.
Turn the heat off and stir in the lemon juice.
Making the Syrup
Place a fine mesh strainer over a large bowl and slowly pour into the strainer. I do this in my sink as the mixture can splash and it's extremely sticky
Shake the strainer until most of the juice has dripped into the bowl, then using a potato masher, muddler, or wooden spoon, work the berries into the strainer until almost all of the juice has gone into the bowl.
At this point, you can discard the remains of the berries or use them for another recipe.
Let the mixture cool completely, then careful pour the syrup into an airtight container (I used a flip top bottle)
Can be stored in the refrigerator for up to two weeks.