A definitive answer can only be given to an actual question sparky.
If you want to try a sweetener, say Ethyl Maltose, do it, give it a bash and see if it works for you.
Make say 10 ml of a juice, add sweetener to one bottle, a couple of drops per 10ml and do one without. Whichever one tastes better...tah dah....
Or you could ask yourself why you need sweeteners, I have a very sweet tooth and flavours I use in DIy always come out lovely and sweet so could be better to lessen one of your flavours if it takes the natural sweetness away from other ingredients? To salvage is one thing but to fix the mix might be better?
I'm actually waiting for my very first mixes to steep so not sure how they'll turn out yet but i do like my sweet liquids.
I was gonna go for the ethyl maltose or stevia. After reading different threads I'm hearing all kinds of different opinions, good and bad for each one so just wanted something on hand should i need something.
@Adam Burgess have never added a sweetener as none of my juices have seemed to need it.. however I use bakery/dessert type flavours so they are already sweet enough.. some fruits I have seen if made from natural flavourings state that they are not sweetened and will need some adding... so if I used those flavourings I would mix up the juice and then add a bit of sweetener at a time till it reached my desired preferences..
Its cheap enough to get a small amount of each and have a play around... keep the mixes small (only a few ml) initially till you have got things where you want them so that there isnt much wastage
If you don't mind the aftertaste of artificial sweeteners in products like diet drinks and no added sugar squash/yogurt or whatever then crack on. Not keen myself like. I had a look at the process that the stevia plant extract goes through to become the final product and to my mind its far from natural by the time they've finished interfering with it.
You could try allterative go for something that's sweet but not a grate deal of taste such a candyfloss from TPA I find adding this's at 2-3% is better than any sweeter. Or if it's a fruit mix your makeing try layer the fruit with a sweeter version of said fruit... I find there to be very little need for sweetener.
I've found that the stuff I mix myself is never sweet enough but honey/maple syrup flavours ruin it completely. Ordered a bottle of marshmallow at the weekend, hoping that'll hit the spot.