I'm pretty sure the blackstrap molasses has a higher nutrient content. Most folks around here use the yellow label Grandma's brand because a lot of stores carry that brand so it's easy to find. I don't know if anyone has done a side by side comparison with/without molasses, but most say it increases bud size by about 20% or so. It will also feed the microorganisms in your soil. It's most commonly used during flowering, but it shouldn't cause any harm to use it throughout your grow.