Midge / EmergersMercury Brassie
The Mercury Brassie is a variation of the classic Brassie developed on Colorado's South Platte River in the 1960s. A silver-lined glass bead replaces the traditional metal bead, imitating the gas bubble effect of an emerging midge pupa. The weighted wire body sinks quickly, making it ideal for dry-dropper rigs.
Year Round
Beginner
Trout
Overview
The Mercury Brassie builds on Gene Lynch's original Brassie pattern with one key modification: the silver-lined glass bead creates a subtle air bubble effect that mimics midges preparing to emerge. Popular color variations include copper, red, chartreuse, green, and black to match different midge species. The simplicity of this three-material pattern makes it quick to tie and extremely durable.
Pattern Characteristics
Materials
Hook: Tiemco 101, #16–#22
Bead: Silver-lined glass bead, extra small
Thread: Black UTC 70 Denier
Abdomen: UTC Ultra Wire, copper
Thorax: Peacock herl
Fishing Tips
Season
Year round, with peak effectiveness during winter and early spring midge hatches.
Presentation
Dead drift along the bottom in a multi-fly nymphing rig. Position as the point fly with a smaller midge pattern trailing behind.
When to Use
During midge emergences, particularly when trout are feeding subsurface. Blue variations excel in low-light conditions at dawn and dusk.
Water Type
Tailwaters and spring creeks where midge populations thrive. Originally designed for the South Platte River's technical trout.
Rigging Suggestions
Fish on 5X–6X fluorocarbon, 18–24 inches below an indicator or dry fly. Effective droppers include Mercury Pheasant Tails, RS2s, Barr Emergers, and Top Secret Midges in sizes #18–#22.
Visibility & Floatation
The weighted wire body sinks quickly to the feeding zone. The silver-lined bead catches light and creates flash, drawing attention from feeding trout.
