The Leaf Index
Vol. IA field guide to cannabis cultivarsleafly.cc
No. 5779Sativa

Ultra Sour

East Coast Sour Diesel × MK Ultra

Ultra Sour is a potent sativa-leaning cultivar celebrated for its sharp citrus and diesel aroma, coupled with long-lasting, head-focused effects. It typically contains high THC levels and minimal CBD, contributing to its crisp and cerebral profile.

May help withFatigue
AromaCitrusDieselHerbalPepperEarthy

Appearance

Ultra Sour buds are generally medium-sized, displaying shades of lime to forest green, sometimes with olive or chartreuse undertones. While rare, faint violet hues may appear in cooler late-flowering conditions. The calyxes are densely covered in trichomes, often appearing frosted, and pistils are typically a vibrant tangerine or pumpkin color.

The bud structure is semi-compact, offering a favorable calyx-to-leaf ratio that can simplify trimming. Internodal spacing is moderate, presenting a more sativa-like silhouette than dense kush varieties, allowing for good cola stacking with proper canopy management.

Aroma & Flavor

The aroma of Ultra Sour is characterized by aggressive sour citrus notes, reminiscent of lemon zest and lime pith, intertwined with fuel-like and black pepper scents. Underlying earthy and herbal undertones, akin to bay leaf or green tea, add complexity. Upon breaking apart the buds, a strong diesel aroma emerges, often described as similar to gasoline fumes mixed with lemon oil.

On the palate, Ultra Sour delivers a high-intensity lemon-lime sourness, followed by diesel and a resinous herbal flavor. The exhale often carries notes of pepper, pine, and a slight green tea astringency. While some phenotypes may exhibit a subtle floral sweetness, the overall profile leans more zesty than sugary, with minimal candy-like notes.

Effects

Ultra Sour produces pronounced head-forward effects, often described as cerebral, energetic, and uplifting. Consumers frequently report increased talkativeness and a heightened sense of focus, making it a popular choice for daytime activities. The onset is typically rapid, occurring within minutes of inhalation, with peak effects usually felt within 30 to 60 minutes and sustained for several hours.

Due to its potent sativa-dominant nature, Ultra Sour is often sought after for its ability to combat fatigue. When consumed judiciously, many users find it provides a clean and functional experience suitable for creative endeavors, social interactions, and task-oriented sessions.

Terpenes & Cannabinoids

Ultra Sour is known for its robust terpene profile, with Myrcene, Limonene, Caryophyllene, and Pinene frequently identified as dominant. This combination contributes significantly to its distinctive aroma and flavor, as well as its energetic and uplifting effects. Terpinolene may also be present, adding further aromatic complexity.

The cannabinoid content of Ultra Sour typically features high THC levels, commonly ranging from 16% to 28% in legal markets. CBD is generally found in trace amounts, usually below 1%, which allows the psychoactive properties of THC to be more pronounced. Small amounts of CBG and THCV may also be present.

Origins & Lineage

Ultra Sour is widely recognized as a hybrid resulting from a cross between East Coast Sour Diesel (ECSD) and MK Ultra. This genetic pairing aims to combine the distinctive sour-citrus and fuel-like characteristics of Sour Diesel with the dense, potent qualities of MK Ultra.

The lineage traces back to the influential wave of Diesel and Kush hybrids from the late 1990s and early 2000s. The goal of this cross was to enhance the sour-citrus terpene profile while maintaining a more manageable plant structure compared to traditional Sour Diesel varieties.

Frequently asked questions

What is the THC content of Ultra Sour?
Ultra Sour typically tests between 16% and 28% THC, with many batches falling in the 20-25% range.
What are the dominant terpenes in Ultra Sour?
The most commonly cited dominant terpenes in Ultra Sour are Myrcene, Limonene, Caryophyllene, and Pinene.
What is the typical flavor profile of Ultra Sour?
Ultra Sour is known for its strong sour citrus and diesel flavors, often accompanied by herbal and peppery notes.
What effects are associated with Ultra Sour?
Consumers often report energetic, focused, talkative, and uplifting cerebral effects with Ultra Sour, making it suitable for daytime use.