1. If your blender is not so powerful or if you haven't blend it enough, it can separate, this is totally normal since we haven't added any stabilizer to our recipe. Just whisk it a bit and it will be all combined again. 2. If you decide to use demerara sugar or any other darker color sugar, the condensed milk will come out in a darker color 3. DO NOT use a Nutribullet type of blender or a completely closed regular blender because the heat and friction will create pressure and will blow up when you open and you can burn yourself! If you're using a regular blender, use a tablecloth instead of the lid or remove the smaller lid on the main lid.