lupulin threshold shift \lu·pu·lin thresh·old shift\ n 1. When a once extraordinarily hoppy beer now seems pedestrian.
2. The phenomenon a person has when craving more bitterness in beer.
3. The long-term exposure to extremely hoppy beers; if excessive or prolonged, a habitual dependence on hops will occur.
4. When a "Double IPA" just is not enough.