A sparge water calculator determines how much hot water to rinse through your grain bed after mashing, and at what temperature to heat it. Proper sparge volumes maximize sugar extraction without over-extracting harsh tannins.
Sparge Parameters
How to Use the Sparge Water Calculator
The sparging step rinses residual sugars from your grain bed after the mash. This sparge water calculator tells you exactly how much water to prepare and at what temperature to maintain efficiency without extracting harsh tannins.
Step 1: Enter your batch targets
Input your target batch size (what you want in the fermenter), grain bill weight, mash water volume, boil-off rate, and dead space. These determine your required pre-boil volume and the sparge water needed to reach it.
Step 2: Select sparge method
Choose batch sparging (one or two additions, simpler) or fly sparging (continuous, slightly more efficient). The calculator adjusts sparge additions accordingly.
Step 3: Follow the sparge schedule
Heat your sparge water to 168°F (76°C). For batch sparging, add the stated volume, stir gently, rest 10-15 minutes, then drain. Always stop before tannin extraction begins — check with a refractometer if runoff drops below 1.010.
FAQ
Is this sparge calculator free?
Yes, completely free with no account required. All calculations run locally in your browser.
Is my data safe?
Absolutely. No data is sent to any server.
What is the ideal sparge water temperature?
The standard sparge temperature is 168°F (76°C). This is hot enough to stop enzymatic activity (which could continue converting starches) and thin the wort viscosity to improve flow, but cool enough to avoid extracting harsh tannins from grain husks.
What is the difference between batch sparging and fly sparging?
Batch sparging adds all sparge water at once in one or two additions, drains, then you collect your wort. Fly sparging trickles water continuously over the grain bed as wort is collected, maintaining a constant liquid level. Fly sparging can achieve slightly better efficiency (5-10%) but requires more equipment and attention.
How much sparge water do I need?
Sparge water volume equals your pre-boil target volume minus your mash runoff. For a standard 5-gallon batch with 10 lbs of grain, mash water is about 3.75 gallons. After grain absorption (~1.25 gallons), mash runoff is ~2.5 gallons. If pre-boil target is 6.5 gallons, you need about 4 gallons of sparge water.
Can I sparge too much?
Yes. Over-sparging can extract excess tannins and harsh polyphenols from grain husks, creating astringency in your finished beer. Stop sparging when your runoff gravity drops below 1.010 or roughly 2.5°P, or when you've reached your pre-boil volume target.