🌿 IBU Calculator

📚 Understanding IBU

What are IBUs?

International Bitterness Units (IBU) measure the concentration of iso-alpha acids from hops in beer. One IBU equals one milligram of iso-alpha acids per liter of beer.

IBU Ranges by Style:

• 5-15 IBU: Light lagers, wheat beers, blonde ales
• 15-30 IBU: Pilsners, kolsch, cream ale
• 30-50 IBU: Pale ales, amber ales, brown ales
• 50-70 IBU: IPAs, porters, ESB
• 70-100+ IBU: Double IPAs, imperial stouts, barleywines

BU:GU Ratio Guide:

• < 0.5: Malty, sweet beer (Scottish ale, barleywine)
• 0.5-0.7: Balanced beer (pale ale, amber)
• 0.7-1.0: Hoppy beer (IPA, American pale ale)
• > 1.0: Very hoppy beer (double IPA)

Factors Affecting IBU:

• Alpha Acid %: Higher AA% = more bitterness potential
• Boil Time: Longer boil = higher utilization
• Wort Gravity: Higher gravity = lower utilization
• Hop Form: Pellets have ~10% better utilization than whole hops
• Boil Vigor: Rolling boil increases utilization

Tips for Calculating IBU:

• Bittering hops are typically added at 60+ minutes
• Flavor hops at 15-30 minutes add some IBU but mostly flavor
• Aroma hops at 0-10 minutes add minimal IBU
• Dry hops don't contribute to IBU (no heat for isomerization)
• Use high AA% hops for bittering, low AA% for aroma

The Tinseth Formula:

IBU = (Weight × AA% × Utilization × 7490) / (Batch Size × Gravity Factor)

Where:

• Weight is in ounces
• Batch Size is in gallons
• Utilization depends on boil time and gravity
• 7490 is a constant (converting mg/L)