When would I dilute my wort?

Common reasons include: pre-boil gravity came in too high, you want to split a high-gravity batch into a standard batch, or you are brewing a parti-gyle second runnings beer. Always dilute with treated, boiled water.

Should I use boiled water for dilution?

Yes, always use water that has been boiled and cooled, or treated with Campden tablets. Adding untreated water risks introducing chlorine or bacteria that can spoil your beer.

Does dilution affect IBUs?

Yes, dilution proportionally reduces IBU concentration. If you add 10% more water, IBUs drop by approximately 10%. You may want to compensate with additional hops if diluting significantly.

Can I dilute at any stage?

Dilution works at any stage: pre-boil, post-boil, or even after fermentation. Post-fermentation dilution must use sterile, oxygen-free water to avoid oxidation and contamination.

Will dilution affect the colour and flavour?

Yes, dilution proportionally reduces colour, bitterness, and flavour intensity. A 10% dilution reduces these by roughly 10%. For significant dilutions, you may want to compensate with additional hops or specialty grain steep.

BrewCalcs

Dilution Calculator — Recipe Design

Calculate water additions to dilute wort or beer to a target gravity.

Current Volume

Current Gravity

Target Gravity

Must be lower than current gravity

How We Calculate This

Dilution Formula

Based on gravity point conservation: V1 x GP1 = V2 x GP2. Where V1 is current volume, GP1 is current gravity points, V2 is final volume, and GP2 is target gravity points. Water to add = V2 - V1.

Practical Application

Measure your current gravity and volume accurately. The calculator determines exactly how much water to add to reach your target. Remember that dilution also proportionally reduces colour and bitterness.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify values and adjust based on your equipment and ingredients.