During my recent café-hopping trip to Australia, one of my stops was One in a Million in Brisbane. The beans they use come from their own independent roasting brand, Blue Sky Coffee Roasters. Before I even left for Australia, I was browsing their website and instantly fell in love with the illustration on the bag of this Treehouse Blend. As many of you know, I have an entire wall at home covered with coffee bean bags. In that moment, I had only one thought: I have to hang this one on my wall. (Proof that packaging really matters, right? 😂)
When I visited the café, I ordered an espresso made with the Treehouse Blend and was immediately drawn in by its flavor performance. I didn’t hesitate—I bought a bag on the spot. And that’s how today’s review came to life.
Although Blue Sky operates independently from the café brand itself, in many ways it’s the “behind-the-scenes hero.” Beyond committing to direct trade at origin, they place strong emphasis on whether their roast profiles deliver consistent, high-quality flavors for home users. In other words, their mission is to bring the café experience into people’s homes—so everyday coffee lovers can recreate café-level results using simple home equipment.
A Roaster’s Philosophy
I genuinely admire this user-centered approach to roasting. Seeking the optimal solution from the customer’s perspective is, to me, a mark of true professionalism.
Blue Sky’s lineup only features coffees scoring above 89 points in cupping. The Treehouse Blend has been the backbone of the espresso program at One in a Million in Brisbane for over two years. It’s a blend of natural-processed Brazil and washed Rwanda. The roast level sits beautifully between modern light roasting and traditional Italian-style roasting—essentially a well-balanced medium roast. It preserves depth and richness while still offering elegant layers of complexity.
Every espresso-based drink made with this blend carries what I’d call a classic “Australian style.” The composition evolves with each harvest season. The foundational structure typically centers on Brazil and Colombia, with natural Brazil always forming the essential “base note.” The secondary component rotates among washed Central American coffees. For the batch I had—both in the café and at home—it was washed Rwanda. Previous seasons have included Nicaragua, El Salvador, and Mexico.
These regions are known for their mild, balanced profiles. When paired with natural Brazil, the result is a complementary and richly layered cup. The goal is simple: maintain a relatively consistent flavor profile across different seasons.
Espresso Experience
The dry aroma of the freshly ground coffee carries a candied sweetness, layered with hints of nuts and chocolate. But once extracted as espresso, the wet aroma and flavor shift noticeably.
In my extractions, I found the crema slightly thinner than some traditional base blends. The acidity on the palate is remarkably bright—so bright it might even catch you off guard for a second. But it’s not one-dimensional. It’s more like a layer of citrus (or yellow fruit) acidity woven into dark chocolate and nutty tones. The bitterness lingers pleasantly, delivering a classic chocolate-like finish with a gentle returning sweetness.
Espresso, however, is just the appetizer.
The True Highlight: Milk-Based Drinks
This is where the Treehouse Blend truly shines. Honestly, I’d call it a milk coffee champion.
I specifically tested it in both a latte and a flat white to explore how varying milk ratios affect the flavor profile.
In a latte, this blend is simply outstanding—the kind of delicious that makes your eyes widen instantly. You’ll taste milk chocolate, cream cake, vanilla, and a beautifully clean caramel note. These flavors are vivid and expressive, and they perfectly match what I experienced in the café.
With a flat white (less milk), the classic chocolate and caramel notes become even more pronounced and concentrated. The cup is clean, rich, and incredibly satisfying. No matter how you tweak it, it just works. It’s one of those dependable blends that tastes great under almost any adjustment.
Black Coffee Variations
I also tested it as a hot Americano and an orange Americano (espresso mixed with orange juice).
In a standard hot Americano, the bright acidity present in the straight espresso essentially disappears. Nuts and chocolate take center stage, resulting in a very balanced, low-acid, low-bitterness profile. It’s slightly more straightforward and less dynamic, but that’s also its strength—it’s broadly appealing. Those who dislike acidity will love it, while acidity lovers won’t find it bitter either. It’s a crowd-pleaser.
As for the orange Americano—one of my favorite quick home creations—I was curious whether the flavors would complement fruit juice. The answer is yes. The orange juice and espresso combination works beautifully. The caramel notes become even more pronounced, and the overall drink feels harmonious and refreshing. It’s incredibly approachable and enjoyable—honestly, a perfect everyday home staple.
In short, the Treehouse Blend isn’t just about beautiful packaging (though that illustration still has a place on my wall). It’s a thoughtfully constructed, seasonally adaptive espresso blend that performs consistently across milk drinks and beyond.
But if you ask me where it truly belongs?
In a silky, chocolatey cup of milk coffee—right where it reigns supreme.
