Beer IBU Calculator
Calculate International Bitterness Units and BU:GU balance using the Glenn Tinseth equation.
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How Glenn Tinseth Calculates Hop Bitterness
International Bitterness Units (IBUs) measure the concentration of isomerized alpha acids in milligrams per liter (parts per million). The Glenn Tinseth utilization model calculates how much alpha acid dissolves and isomerizes based on boil duration and wort specific gravity.
High-gravity wort reduces hop alpha acid utilization because high sugar concentrations impede solubility. Hops added with 60 minutes of boil time contribute primarily bitterness, while late additions (15, 10, or 5 minutes) preserve volatile aromatic hop oils like myrcene and humulene.
Frequently Asked Questions
What is Glenn Tinseth’s IBU formula?
IBU = (Alpha Acid % / 100) * (Hop Ounces * 7490) * Utilization / Batch Gallons. Utilization is calculated by multiplying the bivalent gravity factor by the boil time factor.
What does the BU:GU ratio indicate?
BU:GU compares bitterness units to original gravity points (e.g. 60 IBU / 50 gravity points = 1.20). A ratio of 0.40 to 0.60 is malty and sweet, 0.70 to 0.85 is balanced, and 1.0+ is heavily hop-forward.
Do dry hops add IBUs?
Cold dry hopping after fermentation extracts aromatics and polyphenols with minimal alpha acid isomerization. Tinseth IBU calculations apply strictly to hot-side boil additions.