Last week a huge branch broke off my mulberry tree so I had a surfeit of mulberries shriveling in the sun at easy picking height. I decided to try drying them. I've been impressed before by the sweetness of dried white mulberries from asia that are sometimes on store shelves here. Particularly in baked goods the berries seem to disappear and just leave a sweet taste.
My mulberries are dark purple, but I've learned that they are probably the same species as those white mulberries (morus alba), just a different color due to growing conditions. I want to see whether they will work to sweeten foods as a sustainable, local natural sweetener. Part of my inspiration was a question by Blake Lenoir last year about a local substitute for dates, which many people who adhere to vegan, raw, or paleo diets use to sweeten food.
I picked 300 g and dried them on a cloth on my cedar picnic table. This took the better part of 2 days in a heat wave.
When fully dry, they are brittle and crunchy and very lightweight. They taste sweet, but it's not a sweetness that hits you right away, and some have a bit of fruity tartness also. Opening a bag of them, they have a sweet raisin-y scent.
For my first experiment, I wanted something simple and scalable so I can play around with proportions and not end up with a big batch of something blech. I have a tub of damp hazlenut paste leftover from another project. I have used this mixed with date puree for tasty no-bake treats before, so i will try the same with the mulberries. Because of the texture, I decide to pulverize them:
At first I feel like this is not going to work. Grinding in the mortar and pestle separates out the seeds, and the remaining parts of the fruit settle on top with a texture that I can only compare to pocket lint. However, I persevere and try really pounding rather that grinding, and after not too long the seeds and fruit are basically pulverized. The texture is similar to ground sumac.
As with the whole berries, the sweetness does not hit you immediately when tasting a pinch, but it is there. This would probably be good sprinkled on oatmeal.
I try mixing the powder with my hazelnut paste about 2 parts hazelnut to one part mulberry (by volume, not weight). I form this into balls and let sit an hour or so before tasting.
They are not great; slightly fruity tasting, but not what I would call sweet. Definitely not something to bring to a cookie exchange if you want to be invited back. I retool them by kneading in more mulberry and also rolling the balls in mulberry powder. Even at around 50% mulberry by volume, they're still not really sweet though. Nothing like the ones made with dates. I think this recipe is not a good fit, because the mulberries need more moisture to let out the sweetness.
I'll try some more experiments over the weekend.