Tinseth IBU Bitterness Calculator
Estimate International Bitterness Units with dynamic boil time utilization and boiling wort gravity scaling.
Tinseth IBU Bitterness Engine
Precision utilization factoring wort gravity and boil contact kinetics.
Glenn Tinseth Hop Utilization Formula
IBU = \frac{w \times AA \times U \times 7490}{V_{\text{final}}}Where U is the utilization factor: U = 1.65 × 0.000125^(SG - 1) × (1 - e^(-0.04 × t)) / 4.15. Accounts for reduced alpha acid isomerization in higher gravity worts.
- 1Enter your target finished batch volume (e.g. 5.5 gallons) and boiling specific gravity (e.g. 1.050).
- 2Add each hop addition with its weight in ounces, Alpha Acid % (from packaging), and boil duration in minutes.
- 3The engine calculates individual contribution per hop charge and total composite IBUs.
Recommended Equipment for this Tool
Northern Brewer Copperhead 50ft 1/2" Immersion Wort Chiller
Rapid wort chilling is critical for crisp cold-break formation, beer clarity, and preventing dimethyl sulfide (DMS) off-flavors. Copper conducts heat 28 times faster than stainless steel. Northern Brewer's Copperhead features a full 50 feet of heavy-gauge 1/2-inch outer diameter copper tubing with pre-attached brass garden hose fittings and vinyl input/output lines.
Why do high-gravity beers yield lower hop utilization?
Higher wort sugar concentrations increase viscosity and hydrophobic binding, which hinders the thermal isomerization of alpha acids into soluble iso-alpha acids. High-gravity worts require 10-25% more bittering hops to achieve the same perceived IBU.
Do whirlpool and flameout hop additions contribute IBUs?
Yes! Alpha acid isomerization continues whenever wort temperature exceeds 175°F (79°C). A 20-minute whirlpool at 190°F typically yields 5-10% hop utilization.
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