There's kveik beers and then there's beers made with Kveik yeast. Kveik beers shouldn't be sour, that's usually prompt for the farmhouse brewer to discard their yeast and ask a neighbour for some of theirs. Also, the juniper branches and a small hop addition inhibit the bacteria in contaminated yeast.
From milkthefunk.com.
Yes, I wasn't expecting sour. Interesting that it is the branches of the juniper that has the antibacterial property not the berries. So if I wanted the 'juniper effect' it is branches or make it have a reasonable IBU.