Mash in with a standard mash at 1.25 qts./lb. (2.6 L/kg) at 155 °F (68 °C) until fully converted, about 60 minutes. Sparge with enough water to collect 6.5 gallons (24.6 L) of wort in the kettle. Boil 60 minutes, adding sole hop addition at the beginning of the boil. Add the lactose powder to the boil at any point. Chill, aerate, and then ferment at 67 °F (19 °C) with your favorite English ale strain. On brew day, zest the lime and chop the vanilla bean. Add vodka to bowl to just cover the zest and bean, then cover with saran wrap. Let soak in vodka during active fermentation. Dry hop in secondary with a citrus-forward hop such as Citra® but you can substitute in Simcoe®, Motueka, or a favorite citrusy hop of yours. Add tincture of lime zest and vanilla bean at dry hopping. After achieving the desired dry hop character, cold crash and package.
1-2 limes, zested