Mangrove Jacks M66 Hop Head Ale Yeast 10g

M66 is built for hazy, juicy, tropical IPAs. It produces fruity esters that complement modern hop varieties and is active in hop biotransformation — converting hop compounds into tropical, stone-fruit flavours during active dry hopping. The right yeast for New England IPA.

Best Suited To

• New England IPA (NEIPA), Hazy IPA
• Hazy Pale Ale, juicy or tropical-style IPAs
• American Pale Ale where fruit character is the goal, not a clean or dry finish

Specs

• Fermentation temp: 18–23°C (warmer pushes tropical ester expression)
• Attenuation: Very High
• Flocculation: Medium (produces characteristic permanent haze)
• Alcohol tolerance: Up to 12% ABV
• Pitching rate: 1 sachet per 23L at standard gravity

When to Choose M66

Choose M66 over M44 when you are brewing a hazy or juicy IPA where tropical fruit character is part of the design. M44 is clean and dry; M66 is fruity and haze-forward. Do not use M66 when a clear, West Coast profile is the goal.

Choose M66 over US-05 or M36 when hop biotransformation is the point. M66 actively transforms hop compounds during active fermentation — strains without this activity produce more conventional hop character.

Practical Notes

Dry hop timing matters with M66. Add dry hops during active fermentation — day 2 or 3 — to maximise biotransformation. Post-fermentation dry hopping with M66 misses most of the flavour benefit.

The medium flocculation produces a permanent soft haze. This is expected and correct for NEIPA. Do not fine or cold-crash aggressively if haze is part of the style.

Ferment at the higher end of the range (21–23°C) to push tropical ester expression.

Keep refrigerated. Once opened, reseal and use within 7 days.

Reviewed by the AHB Brewing Team — June 2026.