Preheat the oven to 350°F.
Butter and flour a 9 by 5 inch loaf pan.
Sift together the dry ingredients (flour, juniper, baking powder, baking soda, salt) into a medium sized bowl.
Cream the butter, sugar, and lime zest together until light and fluffy. If using a stand mixer, this will take about 5 minutes on medium speed, longer if using a hand mixer.
Add the eggs one at a time, beating for a minute after each addition and scraping down the bowl as necessary.
Add approximately one half of the dry ingredients and mix on low speed until they are just incorporated.
Add the buttermilk and lime juice and beat until mixed. Scrape down the bowl.
Add the remaining dry ingredients and mix until just barely incorporated.
Pour the batter into the prepared pan, even out the batter and give the pan a few thwacks on the counter to remove any air bubbles.
Bake for about 50-55 minutes until the top has started to brown and a toothpick inserted into the center comes out clean. I would cross my fingers that it doesn't collapse.
Cool in the pan for 10 minutes, and then invert and transfer to a cooling rack.