Don’t Fear the Foam

Here are a few Star San dos and don’ts to help you get the most out of everyone’s favorite wonder foam.

Dave Carpenter Oct 9, 2015 - 4 min read

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Star San is the sanitizer par excellence for pro brewers and hobbyists alike. It’s safe, it’s convenient, and it’s effective. It’s so ubiquitous, though, that even longtime brewers may not pay it a second thought. But paying a second thought isn’t a bad idea when the quality of your beer is at stake. Here are a few Star San dos and don’ts to help you get the most out of everyone’s favorite wonder foam.

DO follow the recommended dilution instructions. Just 1 ounce (30 ml) of Star San in 5 gallons (19 liters) of water is enough to effectively sanitize all of your gear.

DO use the Star San bottle’s handy dosing feature to measure out the amount you need. Ensure that the cap over the main reservoir is closed, and slightly loosen the cap over the smaller dosing cavity. Then just squeeze the bottle until Star San fills the dosing cavity to the level you want. Remove the cap, and pour out your measured dose.

DO allow enough contact time. Depending upon whom you ask, Star San takes anywhere from 30 seconds to 3 minutes to work its way into the microscopic cracks and crevices that can harbor bacteria. Give it time to do so.


DO keep a spray bottle of Star San handy. Every time you whip up a new batch of Star San, fill the bottle with fresh sanitizer to use for other brewing chores throughout the week. Need to take a gravity reading? Just give your thief a good spray of Star San solution and have at it.

DO measure the pH of your Star San solution every so often, especially any that you keep around in a spray bottle. As an acid-based sanitizer, Star San becomes less effective as the pH rises. Use pH strips or a meter to ensure that your solution’s pH remains below 3.

DO NOT worry if your Star San solution turns cloudy. It’s not a reliable indicator of the effectiveness the solution. A pH reading of less than 3 is all you need to convince yourself that you still have a viable solution.

DO consider using distilled or reverse osmosis water to prepare your Star San solution. It will last much longer because the water has fewer dissolved ions to react with it.


DO NOT rinse Star San. Simply shake any excess off and proceed normally. When prepared as recommended, a solution of Star San will not affect the flavor or head retention of your beer.

DO NOT allow undiluted Star San to come in contact with anything other than the bottles in which you prepare your solutions. At full-strength, it can damage countertops, floors, tables, and any number of other surfaces.

Finally, DO NOT fear the foam. The foam is your friend. Embrace it enthusiastically and embrace it often, and you’ll be well on your way to worry-free brewing.

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