Star San Tips, Tricks and Guidelines – Using Star San In a Spray Bottle

star san tips and tricks

Updated: 5/15/2024

Star San is my homebrew sanitizer of choice.  When mixed properly, it’s food safe and no rinse.  Required contact time is five minutes.  It has worked very well for me for quite some time and I’m convinced that it’s one of the most economical solutions available if you’re using the “Spray Bottle Method” outlined here.

Cleaning, Sanitizing and… Sterilizing

The first step in sanitizing is cleaning.  Cleaning and sanitizing are two separate steps.  Cleaning physically removes dirt and large contaminants.  After your item is physically clean it can be microscopically sanitized.  Sanitization kills many (but not all) germs, bacteria and microorganisms on an already clean surface.  I typically use a mixture of PBW for cleaning.  Sanitizing and Sterilizing are different.  Sterilizing is killing every living thing.  In home brewing typically, we’re not interested in sterilizing, we’re only interested in sanitizing.

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The Spray Bottle Method

The key benefit of this method is using what you need.  That fact of the matter is… there’s no need to submerge your equipment in gallons and gallons of this stuff.  The open space in the middle of your carboy does not need to be sanitized.  Just the surfaces do.

Fill up a spray bottle with properly diluted Star San solution and you’re good to go.  Liberally coat all surfaces and parts in need of sanitizing.  If you have a larger job, like a keg or a carboy, use what you need to sanitize (already clean items) and pour the Star San mixture back in the gallon jug for re-use.  That’s it.  Spray liberally, let stand and drain any excess.

Contact Time for Star San

I’ve seen varying reports as low as 30 seconds. I myself advocated for 1 minute for a long time. I had multiple from Five Star Chemicals read this article over the years and never heard any complaints about that guidance. Well, times have changed.

Five Star has some conflicting information on this subject.  The product page current states 1 to 2 minutes.

According to my contact at Five Star Chemicals the required contact time for Star San is five minutes. That’s kind of a good change in my book considering the “Do Not Soak” guidance (see below).


The 5 minute recommendation is laid out in 5 Star’s Craft Cleaning Chart

Star San Temperature Range

The recommended temperature range for diluted Star San solution is 50 deg F to 130 deg F

1 Gallon of Star San – How much Star San do I use for 1 Gallon?

I mix up one gallon of Star San at a time.  Just add 6 CCs of Star San to one gallon of distilled or soft water.  How did I come up with 6 CC/ml?  Dosing rate for Star San is 1 ounce per 5 gallons.  That’s .2 ounces for 1 gallon.  .2 ounces = 5.91 ml.  I round that up to 6 CC/ml.

I use a glass gallon jug for storage.  It takes a while but Star San will eat through thin plastic gallon jugs.  I’ve had it happen and it’s not cool.

Measuring 6 CCs/mLs

I use a syringe to measure the 6 CCs needed.  I’ve used a couple different models over the years.  Some with luer locks and some without.  If you get some with luer lock connections, there’s no need to put anything on the luer lock.

10 cc/mL seems to be a good size.  It allows you to measure 6 CCs and have a little room left over.

Search Amazon for “10 ml syringe”

What’s the Shelf Life of Star San?

The shelf life of Star San concentrate is 1 to 2 years.  Your bottle should have a manufacture date on it.

The shelf life of diluted Star San mixture is a bit more tricky.  The official answer is probably… you should mix a fresh batch each time you use it.  To really test the effectiveness, you need to titrate the solution and test the PPM.

Practically speaking, many homebrewers use and re-use Star San.  If you’re going to do that, the solution should be relatively clear and the mixture should have a pH of under 3.5.  See: What’s the Shelf Life of Star San? – Testing Star San’s Effectiveness from more information

From “Better Safe Than Sorry” Department: If you doubt a mixture it’s better to be safe, dump it and make a fresh batch

Don’t Fear the Foam

There’s no need to rinse Star San and you should not let it dry. Wet with Star San after appropriate contact time = sanitized.

The Spray Bottle method reduces or eliminates foam. If you do decide to do a full deluge and end up with some foam, there’s no need to fear.  When mixed with wort, the pH of properly diluted Star San changes and it becomes a… yeast nutrient!

Star San Materials Compatibility

When Valuebrew released FDA Rated EPDM Keg O-Rings I did some digging on EPDM and learned that it’s pretty cool stuff. EPDM is the choice of many professional brewers and has some real advantages over silicone. One of the big ones is a much lower permeability. That means they seal better and since they’re less porous they are more resistant to absorbing off-smells and off-flavors.

Anyway, that’s the back story behind this section. While researching EPDM I found some nice materials compatibility charts showing what materials were compatible with what chemicals. Nice!

This made me wonder, what about Star San and PBW??

I reached out to Five Star Chemicals for some information on the subject. Unfortunately, a comprehensive run-down of compatibility was not available at the time I reached out to them.

I received this response from Ryan Alcala at Five Star Chemicals… “When it comes to our products they are compatible with stainless steel, glass, and rubber. They are not however compatible with softer metals like copper and aluminum.”

There are lots of materials we use that aren’t specifically listed in that list. I’m guessing both Star San and PBW have good compatibility with many of the materials we use. But, without a resource outlining materials compatibility, there is no definitive answer.

I can tell you from personal experience that Star San dissolved a plastic gallon jug that I had used for storage. It took a long time, but it started to dissolve the plastic. What kind of plastic was the jug?… I don’t know. But Star San was not compatible with that plastic for that amount of time. That Star San solution had dissolved plastic in it.  This is why I went to glass jugs.

That story is an illustration to make the point that just because we can’t see something happening doesn’t mean it’s not happening. Is Star San or PBW breaking down keg components, tubing and more?  I don’t know.

Personally, I’m going to try to limit contact time for both Star San and PBW as much as possible. Minimizing contact time will minimize any negative affects these chemicals have on homebrew gear.

Do Not… Soak

My initial thought is compatible = compatible. But… there’s also a time component. Just because Star San is compatible with a material doesn’t mean it’s compatible for any conceivable length of time.

From my contact at Five Star Chemicals… “Star San is an acid based sanitizer so if you are just leaving a piece of equipment soaking in it for hours it will eventually damage it”

Contact time for Star San is five minutes. That’s about how long you should leave a part sitting in Star San. Excessive time can cause damage.

Two materials that are an exception to this are stainless steel and glass.

Testing pH

41s3XP8RicL._SX385_If you’re going to re-use diluted Star San mixture, you may want to test your solution to make sure it’s under a pH of 3.5.  If you source pH test papers for this, make sure they read in that range and, preferably, have a reference point right at 3.5.  I recommend the Micro Essential Labs strips linked below.  They are also featured in my post on Star San Effectiveness.

pH Strips and Meters…

What Size Star San Should I Buy?

Considering the shelf life of Star San concentrate is 1 to 2 years, If you’re using the Spray Bottle Method outlined here, I generally recommend an 8 ounce bottle.  8 ounces of concentrate yields about 39 gallons of mixed solution.  Let’s say you use 1/4 gallon (which I personally think is high) for each batch, the 8 ounces size yields enough for around 157 batches. If you brew more than 157 batches per year, maybe get a bigger bottle.  Otherwise, 8 ounces is probably good. 🙂

Spray Bottles to Use With the Spray Bottle Method

As mentioned previously, Star San can dissolve plastic over time.  Look for a chemical and acid resistant spray bottle.  The ACC130 is a professional quality, chemical resistant bottle and sprayer.  Check out my [

Good Sanitation Starts with Cleaning – Finding PBW Homebrew Cleaner

An important part of sanitizing effectively is starting with something that’s already clean.  I use PBW also from Five Star Chemicals.

Unlike Star San, I go through a lot of PBW.  Under the premise of, buy things in bulk that you use in bulk, I suggest buying the largest size of PBW that makes sense for your budget.

Related: Five Star PBW Homebrew Cleanser Tips & Tricks, Compare Prices & Buying Guidance!

Finding Star San

Compare Offerings, Find the Best Deal

Availability of 4 to 16 Oz Sizes

In 2022 smaller Five Star Chemicals apparently discontinued smaller 4, 8 and 16 oz sizes of Star San. You may not have noticed this if your favorite retailer had enough stock on hand.

From an anonymous industry insider… “According to our latest conference call, 5 Star will start shipping 4-16oz bottles of Star San again. It is unclear if they changed their minds about discontinuing them or if it was a supply chain issue all along, but they will be back in stock at all the major retailers soon.”

So, at least as of this update it seems that smaller sizes will continue to be available.

1 Gallon Glass Jug for Star San Storage

Savings Estimations

Note: This section uses the 32 oz size for estimations.  I generally recommend purchasing the 8 ounce size for most homebrewers.  See: What Size Star San Should I Buy? for more info.

Let’s use the 32 ounce size of Star San for estimation purposes.  32 ounces =  about 946 Milliliters.  At 6 mL per gallon, 32 ounces of concentrated Star San yields about 157 gallons of properly diluted sanitizer.  This is true whether you use the Spray Bottle Method or the old Deluge Method (filling everything up to the brim with Star San).

Let’s say you use a quarter of a gallon per batch using the Spray Bottle Method – I’d make the case that you’d actually use less, maybe significantly less, but let’s be conservative and say 1/4 gallon (32 ounces diluted solution).  At that rate, 32 ounces of concentrate would be enough to sanitize around 628 batches of homebrew.

Compared to the Deluge Method:  For estimation purposes, let’s say the typical brewer would fill a 6 gallon carboy completely full of Star San, use that to sanitize the fermenter and use that same Star San to sanitize everything else that needs sanitized for that batch.  Let’s say that 6 gallons is used up and discarded during the course of finishing each batch of beer from fermentor to bottling or kegging.  Assuming all of that is true, 32 ounces of concentrated Star San lasts for about 27 batches of homebrew.  Compare that with my estimation of a whopping 628 batches using the Spray Bottle Method.

Cost Savings: Let’s say the a 32 ounce container of Star San costs $25 for estimation purposes.

  • Spray Bottle Method – estimated 628 batches sanitized for $25
  • Deluge Method – estimated 26 batches sanitized for $25.
  • To sanitize the same 628 batches using the Deluge Method, you’d have to purchase about [24] 32 ounce bottles of Star San at a cost about about $600 if each bottle is $25.
  • $25 or $600?  With these assumptions and estimations, the Spray Bottle Method saves the average brewer about 96%

If we take this one step further and say… you can get a full batch out of 1/8 gallon or 16 ounces, which I think is very possible the numbers start getting crazy.  1,256 batches per 32 ounce bottle of Star San.  Using my same parameters, you would need to purchase 46 bottles to sanitize the same number of batches using the Deluge Method.  That would be $25 in cost vs $1,200.  Or, a $1,175 savings.

Frankly, I think most homebrewers can sanitize an entire batch, from fermenter to keg or bottle using 1/16 gallon of Star San or 8 fluid ounces of diluted sanitizer.   Those numbers become even more crazy.

In fairness, you could realize similar savings by re-using the 6 gallons of Star San (that’s produced by the Deluge Method) over and over.  However, you’d have to store that and lug it around as necessary and you’d be re-using sanitizer.  If we take our 1/4 gallon estimation and say that that’s the amount that actually gets used up each time, that would mean some of this 6 gallons would have been used 24 times before it’s finally discarded.  The Spray Bottle Method has you using fresh Sanitizer whenever you need it and discarding it after use.

Now I know why my first bottle of Star San lasted well over a half a decade.  If you use 16 ounces of diluted Star San per batch, a 32 ounce bottle lasts for 1,256 batches using these estimates.  At 2 batches per month the bottle would last for just over 52 years.  Practically speaking, it’s probably not going to last that long with keg cleaning, line cleaning and so on, but it really does last a long, long, long time using this technique.

Be Careful

Star San is an acid.  You should be careful with Star San, especially in its undiluted form.  It can cause damage to clothing [See: Lesson Learned, Don’t Do This with Star San], countertops, aluminum items and more.  Make sure materials you use are compatible and rated for your intended application.  Contact manufacturer with questions about suitability or a specific application.  Always read and follow manufacturer’s directions.  Always read and follow manufacturer directions.

What is Star San?

Star San is a self-foaming acid sanitizer ideal for brewing, dairy and other food and beverage equipment. It is an extremely effective bactericide and fungicide and is not affected by excessive organic soils. Star San also reduces water spotting and can be used without rinsing under the proper concentrations. STAR SAN is a blend of phosphoric acid and dodecylbenzenesulfonic acid. This synergistic blend provides a unique killing system that is unaffected by excessive organic soils. STAR SAN is also a self-foaming sanitizer. It can be applied through a foamed to produce self-adhering sanitizing foam for external sanitation. STAR SAN is also an excellent sanitizer for hand application. Sanitizing with STAR SAN on a daily basis will leave equipment in an acid condition that will eliminate water spotting.

Star San Material Safety Data Sheet

StarSan MSDS – MSDS Dated 6-6-12

Five Star’s Craft Cleaning Chart PDF

Craft Cleaning Chart – temperatures, dilutions and times

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Make sure the components you use are compatible and rated for your intended application.  Contact manufacturer with questions about suitability or a specific application.  Always read and follow manufacturer directions.  tag:lnksfxd toppost:starsanspraybottlemethod rs:7 tag:tpr

33 thoughts on “Star San Tips, Tricks and Guidelines – Using Star San In a Spray Bottle

  1. Tom

    Don’t soak?
    Absolutely correct, especially if you use duotight parts.

    Turned my parts (two days in proper dilution) brittle and unusable.

    Now I know.

    1. admin Post author

      I’ve asked that same question and haven’t received a direct answer. I had someone forward me an answer they received and the jist of it was… no, It’s not intended or approved for that sort of a use. Right now I have no official answer and as such recommend against this application. If I hear anything back, I’ll get out an update. Cheers!

  2. pjcamp

    I use this on buckets and air locks but I can’t for the life of me see how you get it down inside a carboy.

    1. Matthew

      Pour it into the carboy, not a lot, just enough so that when you lay it on its side none pours out the neck. Then you roll it so it coats all the way around the sides. Then you can plug the neck and tip it completely over to get every surface at the top. Done!

  3. Apestpro

    Has anyone use star san HB after its EXP LOT, and if so, for how long after its EXP LOT will it be ok for ?

  4. Jim Turcotte

    I realize this is an old post, but maybe someone will read this and respond. I like the spray bottle idea to stretch the starsan. What about sanitizing bottles? Any ideas or methods?

    1. admin Post author

      Hey Jim! For bottles, you can either use a spray bottle or there are some bottle sanitizing pumps, I think made by Ferrari, that work pretty well. They can either go right on top of your bottle tree or sit on a table top.

  5. dennis fontecchio

    do I need to rinse my wine bottles after I fill and shake out the star san or just let them drain and dry upside down?

    1. admin Post author

      If you’re using properly mixed solution, there is no need to rinse or dry. Rinsing negates the sanition. You can drain the excess solution and bottle right away.

    1. admin Post author

      I spray several squirts and then carefully shake or roll the carboy to get 100% coverage.

  6. Dan

    Spray this mixture on corroded battery terminals and prepare to be blown away with how well it helps to clean them. Seriously, takes just seconds. Don’t be stranded this winter!

  7. Jacob M Pitsch

    I use the ml measurement on the reverse side of the Star San bottle. It calls for 30ml/gal, so I simply measure up to 6ml.

  8. EchoTony

    I’ve been using the spray bottle method for a few years with great success. I normally mix up a 5 gallon batch and fill 2 spray bottles with that. I then use the bucket full that’s left for soaking keg parts, auto siphon bits, transfer lines, airlocks, and bungs. I use the spray bottles on everything else (and on the parts that were soaked if needed as well). My 5 gallon bucket normally has about 3-4 gallons after I fill the bottles and brew a batch. I then put the lid on the bucket and keep it for at least 2 weeks, if not much longer. The bottles I will use until empty. I’ve never had an infection issue.
    My water his very hard and the solution will turn cloudy in just one day. If the cloudy solution was the sign of it going bad, then I’ve been wasting my time trying to sanitize at all. But since I’ve been using this method for over 5 years (since switching from bleach and later iodine) with no infections, I think cloudy solution is not a good measure of the quality of your solution.

  9. J

    Star San will cause pitting in stainless according to the information shared on the previously mentioned BREWING NETWORK podcast (as I recall). Long term storage is not recommended in kegs unless that is the purpose of that particular keg.

    1. sc

      I believe they said ‘plain water will pit stainless faster than StarSan would’. I keep StarSan in a keg for dispensing, have done for years (same keg, 3+ years). I fill 2.5 gallons (due to my usage rate) – there is absolutely no visible pitting or ‘fill line’ i can see on the keg’s internal wall. I mix per the StarSan instructions (.5 ouce in 2.5 gallons of distilled water – technically I round up to 15ml/cc).

      Think about it – Star San is about as acidic as soda; these kegs were designed for Soda. When I see people claiming it ate stainless, it is usually a small part or something – probably something that is chromed or plated and not actual stainless (chinese ‘stainless’ or chromed or something else). I’ve never seen one report of a keg or other proper stainless object being damaged by StarSan. I have seen a number of other people say they keep it in there for years like I do, no problem. StarSan on tap is fantastic! I can dispense straight to a carboy/keg for sanitizing, re-fill my spray bottle whenever, and put any ball lock fitting/hose/etc on the tap to fill it with sanitizer right-quick (no disassembly required).

      My 2c. If anyone has a confired report of StarSan damaging stainless, please post (including what grade stainless and how long the contact time and what concentration of StarSan)

  10. Scott Millican

    So, how long in a plastic jug does it take to eat through it. I mean it comes non diluted in a plastic container…granted not the same type of plastic container, but still.

    I store mine in distilled water jugs that I use for another purpose. Been sitting with diluted star san in them for 3-4months and no leaks as of yet.

    1. admin Post author

      It took quite a while the time it happened to me. Longer than 3 or 4 months, but it’s been a while and I’m not exactly sure. I would say maybe I had a bad gallon jug or it was somehow otherwise damaged, but I’ve had other people say this has also happened to them.

  11. Toby

    Thanks for the write-up! Always a good idea to reduce chemical waste/consumption. Just a note on the following line:
    “If you have a larger job, like a keg or a carboy, use what you need to sanitize (already clean items) and pour the Star San mixture back in the gallon jug for re-use.”

    In microbiology research, it is basically a cardinal sin to re-use any sanitizing solution. The reason is that once you have used the sanitizing solution, it is contaminated and weakened (even if just slightly). In practice, the solution may still have enough “sanitizing power” to do a sufficient job, but it definitely violates best practices.

    Whatever you choose, I wish you a happy and infection-free brew. Cheers!

    1. admin Post author

      Thanks for the thoughts Toby! For a laboratory scenario, I think that guideline is very reasonable. For what we’re doing, I think that you can re-use sanitizer with good practical results. For additional information I would refer people to the 3/19/2006 episode of the Brewing Network’s “The Session”. Charlie Talley one of the founders of Five Star Chemical Company (the makers of Star San) give some thoughts on it’s use for homebrewing.

  12. Noiz Boy

    The “thing” is mentioned in their email to you. It’s the surfactant. What that is, is a chemical that lets another chemical coat and get into the knocks and crannies.

    SO the problem is that while the PH is fine and it will kill whatever it touches, if it’s surfactant is not working it won’t touch everything it needs to. THAT is the problem.

    You are talking about saving a few pennies by putting 5 gal of homebrew at risk. Hmmm the math isn’t that hard.

  13. Anonymous

    I keep a StarSan solution in an old 5 G bottling bucket. Its easy to dispense into a tray to soak stuff in on brewday and then I just pour it back in the bucket (provided it didnt get mucked up). Its really decreased my sanitzer waste.
    By the way, I emailed Five Star and they reported that starsan will not dissolve plastic buckets.

  14. Anonymous

    i would also find out exactly what the “cloudy” “thing” is that you speak of that is not chemically good for sanitization, rather than saying “cloudy thing”..sounds less credible..

  15. Anonymous

    how does cloudiness negatively affect star san? i’ve seen videos of experimentation on this subject. as long as the pH stays balance it should work just fine

  16. Homebrew Finds

    I don’t completely understand the chemistry, but there are two components to the sanitizing power of star san. One is pH.

    The other is some other thing that I don’t know what it’s called. 🙂 But whatever that thing is, when the solution gets cloudy, it’s that thing coming out of solution.

    So, pH is not the only indicator of effectiveness.

    I used cloudy star san for quite a while before learning about this without an issue. I don’t think anyone is saying it does no good at all. I think it has something to do with how much of the whatever it’s called has come out of solution.

    I say better safe than sorry. Distilled water costs under a buck and with this technique a gallon last a long, long time.

  17. Anonymous

    There’s been quite a few tests done on the PH of starsan that has been used in hard water or gotten cloudy after a period of time and the PH level stays where it needs to be. I think it’s a marketing ploy to make you dump it and use more! 🙂 Check out all the threads at HomeBrewTalk for discussions about it.

    1. Marcus

      The PH, according to the article is only part of the issue. It is not the PH itself that causes the cloudiness, but rather the metals in the hard water that bind to the sanitizing agent in StarSan that causes the cloudiness. How much of this chemical agent that becomes “bound’ and is no longer present in effective concentration to sanitize becomes the issue.

  18. Anonymous

    I put starsan into a corny keg, and have it on tap next to my brewstand. Use distilled water and it will keep forever. I use a spray bottle too, but I just refill it from the keg, it also allows me to flush hoses and anything else without any problems.


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