Five infected batches

[the-adjunct-hippie]

I can't for the life of me figure this out. 3 of them were stouts, 1 of them was an IPA, and one of them I'm not sure is infected, but it's a little snappier than I'd like (PB&J beer).

I recently picked up some green Menards buckets (HDPE 2, food safe), brand new never used :

https://www.menards.com/main/menard...0-c-7113.htm?tid=-4242568597668123607&ipos=21

https://www.menards.com/main/housew...7-c-7113.htm?tid=-4242568597668123607&ipos=35


The first infected beer came from the top pail. The spigot leaked while we were on vacation and I deduced that if there was liquid coming OUT, there had to be bacteria going IN. I tossed it.

The second infected beer came from my Mr. Beer fermenter which has NEVER had a problem with infection. I chalked it up to not using enough sanitizer and vowed to use more next time.

The third infected batch came from another one of the pails posted in the top link. This one I could see a problem with as we had fruit flies in the house and I did catch a couple around the lid when I went to check the gravity.

The fourth and fifth ones though, I am really scratching my head.

Fourth batch was just dumped. It was made in the square bucket in the second link. Has a proper lid and everything. I sanitized the **** out of it. Filled it to the top with piping hot water, dumped my C-Brite in (which I have used since the beginning), let it soak for 30 minutes, dunked the lid in for 30 more minutes, sanitized everything I touched, and it still ended up infected. This was a big one. It was a chocolate-peanut butter-coconut stout. I re-used the bagged peanuts and bagged coconut from the boil, placed them in a sanitized dish and rinsed them with sanitized water before sticking them into the fermenter right after the wort and yeast were pitched. Awful vinegar flavor. I easily spent $25 on this 3 gallon batch. I am livid.

The fifth batch is a little more tart than I'd like. This was made in the Mr. Beer fermenter which I also scrubbed out thoroughly and soaked with C-Brite for an hour. It's a peanut butter jelly beer and the grape jelly flavor has just a little more acidity which I'm picking up faint infection - though I'm not 100% sure it is yet. The gravity reading on this one is 1.020 so it's almost finished. Lids were not opened or touched, buckets not shaken, nothing happened to these beers but sitting there fermenting at a comfortable 70 degrees.

US-05 was used in all batches. I've been much less careful in the past with sanitization and all my beers up until a month ago have turned out near perfect.

Is it these stupid green pails??

Also of note, these are all relatively small batches ~ 1.5 gallons in a 3 gallon or 4 gallon bucket. Too much headspace?

Everything I've told you is everything I've done. There is no mystery between the time I dump the wort into the sanitized bucket, pitch the yeast, and take a gravity reading 2 weeks out.

I'm going mad here. Our water softener is out of salt, and my wife suggested that was the problem. I can't for the life of me figure it out and it's gotta stop.

Help?

Thanks

 

[Transamguy77]

You mentioned using c brite, what are you using to sanitize? C brite is a cleaner.

Where are you fermenting at? Is the area damp and humid? If so it might be an airborne infection. If so make a simple pale ale and ferment it in a different part of the house.

 

[the-adjunct-hippie]

You mentioned using c brite, what are you using to sanitize? C brite is a cleaner.

Where are you fermenting at? Is the area damp and humid? If so it might be an airborne infection. If so make a simple pale ale and ferment it in a different part of the house.

Good questions. So here's the answers :

I am fermenting in my kitchen and it is like the rest of our house, relatively mild with not much dampness.

My big problem with this, is that I have used C Brite (I will be graduating to a new sanitizer soon once this big batch runs out) from the beginning of my brewing which includes over 3 dozen batches with no problems. I have fermented in the same part of the house, used the same techniques, the same everything. I have been churning out some fantastic beer. And all of a sudden, within 2 months, I get five batches that are s^@t. I did have a Saison turn out fairly well though, and a golden ale that is promising so far.

It seems the dark beers are the ones causing the problems. A boil will kill off bugs right? Do I need to toss my roasted barley? Is this what it's coming to?

I can't figure this out. It's almost a random rain cloud just decided to rain on my love of brewing.

 

[GPP33]

Replace everything that is plastic which touches wort after it’s been boiled. This includes hoses, o-rings, gaskets, siphons, buckets, etc.

Sterilize everything that is metal. Don’t stop at sanitizing, sterilize it.

Fully disassemble anything that can be disassembled such as ball valves and sterilize them.

Putting things like peanuts into the fermenter sounds dangerous. I’m not sure you can fully sterilize a peanut and I’m pretty sure they have all kinds of things living on/in them. Maybe soak that stuff in vodka before adding to primary or at least let the yeast really get a good foot hold first.

 

[IslandLizard]

Not using a true sanitizer (Starsan or Iodophor) could be the culprit, but have you ruled out any infection areas higher up the brewing chain, like a dirty kettle valve or racking equipment harboring bugs?

Most plastic surfaces can be effectively sanitized with bleach, UV (bright sunlight), or Iodine based sanitizers. Most plastic (transfer) tubing is cheap enough and easiest replaced.

Is your yeast OK? Repitching yeast can easily propagate infections.

 

[S-Met]

I didn't see any sanitizer in your process. C-Brite is a cleaner, but did you use a sanitizer like starsan, iodofor or bleach?

Did the infection start with the new buckets? If they were from the store you dont know how they were treated in display. A sanitizer can help. They may have scratches inside that can harbor bacteria.

 

[RPh_Guy]

Ok no one has spelled this out yet. Here we go.

Infections, or rather contaminations, are caused by microbes (microorganisms). Both yeast and bacteria can be culprits. There may be yeast left over from a previous batch or there may be wild yeast or bacteria introduced via the air or surface contact. Wild yeast and bacteria are basically everywhere. We're covered and filled with microbes to such an extent that they outnumber our own cells.

In brewing our goal is (normally) to allow our choice of yeast pitch to complete the fermentation without interference or flavor contribution from any other microbes.
To do this we need to kill them on the surfaces of our brewing equipment, limit air exposure, and kill microbes on anything that may touch the wort and beer after it is boiled.

SANITIZER solutions are used to kill microbes. Popular sanitizers include starsan, iodophor, and bleach, among many others. Ideally they are no-rinse because rinsing with water may introduce new microbes. Water is not sanitary, generally speaking.
To effectively sanitize, we need the surfaces to be clean, which means first using a CLEANER, such as c-brite*. Cleaners generally do not kill microbes.
*I'm not really familiar with c-brite specifically but I believe the other folks here who say it's not a sanitizer.

"Sanitization" in brewing refers to the removal of potential beer contaminants (certain yeast and bacteria), not necessarily all microbes or spores. "Sterilization" means everything dies... Metal, glass, and silicone parts can be sterilized with prolonged heat. Plastics need to be thoroughly soaked in sanitizer solution, although scratches may limit penetration, decreasing the effectiveness of the sanitizer. Cheap plastic or rubber parts/tubing should be replaced if they are a possible source of contamination or if they become scratched. Avoid using any abrasive mechanical action on plastics (scrubbing) because microabrasions may occur, allowing the surface to harbor microbes.

 

[mongoose33]

I'll propose a different idea; perhaps your infections are from multiple sources.

The first infected beer came from the top pail. The spigot leaked while we were on vacation and I deduced that if there was liquid coming OUT, there had to be bacteria going IN. I tossed it.

If you had an airlock on the fermenter, nothing should have gotten in other than air. What liquid are you filling your airlock with? It's common for people to use either Star-San solution or perhaps Vodka. So I don't see the leak as a contributing factor, UNLESS you're not using an airlock.

The second infected beer came from my Mr. Beer fermenter which has NEVER had a problem with infection. I chalked it up to not using enough sanitizer and vowed to use more next time.

As others have noted, sanitizing may be the culprit. You're using a cleaner, though it's marketed as a combination cleaner/sanitizer. No reason why there couldn't be some accumulated junk in there that the cleaner (or your scrubbing) missed. Come to that, when you "scrub" how do you do it? I am not familiar w/ the Mr. Beer apparatus, but I think it's plastic. I have some plastic fermenters; one thing I NEVER do is scrub those plastic fermenters with something like a scotch-brite pad. I don't want to create scratches in which junk can collect, and not be easily cleaned out. That junk, of course, will harbor whatever microbe happens by. I use wet paper towels and copious amounts of cleaning solution.

The third infected batch came from another one of the pails posted in the top link. This one I could see a problem with as we had fruit flies in the house and I did catch a couple around the lid when I went to check the gravity.

Again, airlocks? Or when you opened the lid are you theorizing a fruit fly got in there?

Fourth batch was just dumped. It was made in the square bucket in the second link. Has a proper lid and everything. I sanitized the **** out of it. Filled it to the top with piping hot water, dumped my C-Brite in (which I have used since the beginning), let it soak for 30 minutes, dunked the lid in for 30 more minutes, sanitized everything I touched, and it still ended up infected. This was a big one. It was a chocolate-peanut butter-coconut stout. I re-used the bagged peanuts and bagged coconut from the boil, placed them in a sanitized dish and rinsed them with sanitized water before sticking them into the fermenter right after the wort and yeast were pitched. Awful vinegar flavor. I easily spent $25 on this 3 gallon batch. I am livid.

I don't get this (other than the livid part, been there ). You used "sanitized" water; what does that mean? Water with C-brite in it?

The peanuts and coconut; are you saying you had them in the boil (which should have sterilized them) and just dumped them in the fermenter? But before you "sanitized" them?

Your spigots: do you ever take them apart and clean them separately? I have spigots on my bigmouth bubbler fermenters, and I always take them off and clean and sanitize them separately, every time.

The fifth batch is a little more tart than I'd like. This was made in the Mr. Beer fermenter which I also scrubbed out thoroughly and soaked with C-Brite for an hour. It's a peanut butter jelly beer and the grape jelly flavor has just a little more acidity which I'm picking up faint infection - though I'm not 100% sure it is yet. The gravity reading on this one is 1.020 so it's almost finished. Lids were not opened or touched, buckets not shaken, nothing happened to these beers but sitting there fermenting at a comfortable 70 degrees.

Again, what does "scrubbed" mean?

Also: when you say "fermenting at a comfortable 70 degrees," is that the temperature of the wort, or of the ambient surroundings? Yeast is exothermic, meaning it produces heat as fermentation progresses. This can raise the temp of the fermenter 5-10 degrees higher than ambient, which would put fermentation temps at 75 degrees or higher. The higher the temp, the more the yeast can be throwing off unwanted flavors.

Fermentis says S-05 has a recommended range of temps from 64-82 degrees, but when I've used it I'm on the low side of that range.

US-05 was used in all batches. I've been much less careful in the past with sanitization and all my beers up until a month ago have turned out near perfect.

I read someplace that new brewers, if they're going to get an infection, typically get it around their 10th batch. The reasoning is that this is the point when they may get a little cocky and lax in their cleaning and sanitizing, stuff starts to accumulate in their equipment where infections can take hold, and whambo! Infection. My first infection was my 15th--and hopefully last--batch (I'm up to 57 batches).

Is it these stupid green pails??

Unlikely, if you've properly cleaned and sanitized them (though again, you're not sanitizing). While supposedly green pails like this are food-safe, I wouldn't use a pail other than white. Harder to see if they're clean. But new, they should be pretty clean.

Also of note, these are all relatively small batches ~ 1.5 gallons in a 3 gallon or 4 gallon bucket. Too much headspace?

No.

I'm going mad here. Our water softener is out of salt, and my wife suggested that was the problem. I can't for the life of me figure it out and it's gotta stop.

I'm not a water expert, though I do take pH in my mash, use RO water to build up my water, and so on. My understanding of "softened" water is that the ions in the water are replaced through "softening" with something else. This changes both the composition of the water and, to many people, how it tastes.

So yes, your flavors could be different due to the water. It may not be infected, just tastes "off."

*********

So, how do you proceed?

First, I'm not familiar with C-Brite. I looked it up; it's presented as both a cleaner and a sanitizer. But it's also presented as "chlorine-based," which I'd never want in my system. I'm automatically suspect of something presented as both a cleaner and a sanitizer; further, it's described as "no rinse" but I'm having a hard time with that.

I'd guess most brewers here on HBT use something like PBW (Powdered Brewery Wash) or Alkaline Brewery Wash, or even make their own stuff using an oxy-clean type of ingredient. I'd probably be ok using C-Brite as a cleaner, though not as a sanitizer. It is not, based on what I see here, a commonly-used cleaner, which tells me something.

Here's something interesting: if you google C-brite, you don't get the usual homebrew suppliers coming up first. They're all places I've never heard of before. On a hunch, I searched for it at four sites I've used a lot: Ritebrew, MoreBeer, Northern Brewer, BrewHardware. NONE of them sell it.

Tells me something.

************

For sanitizing, I'd say the vast majority use Star-San. Tasteless, and in fact, when you leave behind Star-San foam clinging to the sides of a fermenter, you don't need to get rid of that. It's a true no-rinse sanitizer. I've even tasted it; doesn't have a flavor. It's acidic, pH around, IIRC, 2.5

I keep a 5-gallon bucket of it, lasts months. I'd get some (yeah, I know, we're not made of money), but it does last a long time and it's really good stuff.

So, hopefully the above is somewhat helpful. Good luck and I hope you get back to non-infected batches on the next brew day!

 

[Hoppy2bmerry]

What common equiptment have you used in those batches? Syphons tubing etc. Also, look at things that should be disassembled like spigots... Bottling wand tips can harbor gunk. You don't need to toss everything, but you need to sanitize everything cold side, as advised above

 

[homebrewer_99]

I read that #2 is GENERALLY food safe. IMO, that doesn't mean they are ALWAYS food safe.

If you're going to go cheap then I'd recommend buying some frosting buckets from the bakery at WalMart. They are only $1 with lid. They need to be cleaned several times to get the vanilla aroma out. The lids are the same type that come with primary buckets sold at brew stores. You just need to drill a hole for an airlock gasket.

Personally, I don't brew in them. I pre-weigh the grains for future batches and store it in them. If wheat is used I keep that in a bag because it needs to be ground separately. Then I label the lid with the recipe name and contents. I keep about 5-6 of them filled up and stacked for when the urge to brew hits.

 

[kh54s10]

From an old thread I read, someone wrote to the manufacturer of the Home Depot orange buckets and they said that the plastic itself was food safe but cautioned that it maybe wasn't still food safe after making it orange. I would get white buckets.

I feel your problem is probably prior to fermentation. Siphon tubing, the buckets, spigots etc. Replace as much plastic as you can.

Get some Starsan. 16 ounces is about $20. My bottle of Starsan lasted 7 years and over 100 batches. Try other water. I have read that softened water is not really good for brewing.

I do consider myself lucky, but wonder how some get many infections. I am not anal about sanitizing and have never had an infection in 7+ years. Even when dropping things into the wort that were not sanitized.

Look to anything uncommon to those bad batches as safe. And anything used in all those batches as suspect.

Throw out any plastic that was "scrubbed" with anything more abrasive than a washcloth.

Clean, clean, clean, sanitize, sanitize, sanitize, sanitize....

Good luck.

 

[kl Roosevelt brewer]

I am only on my 3rd extract beer batch and Pitch the yeast last night and this morning it's working nicely. I use star San and I would have to say I'm more careful with beer than I am with my wine because of all the threads I have read about infections. What is an infection and what does it look like? When does it show up in how do you know when you got it? I've never had one or seen one and it sounds really scary and have been brewing wine and Mead and cider for years but just started the beer thing. I use a Northern Brewer fermenting bucket and do not use a secondary primary for the beer so I can't see in it to tell if there is an infection or not except when I briefly pop the lid for dry hopping.

 

[Andrew Hodgson]

I am only on my 3rd extract beer batch and Pitch the yeast last night and this morning it's working nicely. I use star San and I would have to say I'm more careful with beer than I am with my wine because of all the threads I have read about infections. What is an infection and what does it look like? When does it show up in how do you know when you got it? I've never had one or seen one and it sounds really scary and have been brewing wine and Mead and cider for years but just started the beer thing. I use a Northern Brewer fermenting bucket and do not use a secondary primary for the beer so I can't see in it to tell if there is an infection or not except when I briefly pop the lid for dry hopping.

Check out this thread, most of these are intentional infections but you get the idea:
https://www.homebrewtalk.com/forum/threads/pellicle-photo-collection.174033/page-64#post-8337331

 

[mongoose33]

From an old thread I read, someone wrote to the manufacturer of the Home Depot orange buckets and they said that the plastic itself was food safe but cautioned that it maybe wasn't still food safe after making it orange. I would get white buckets. .

My understanding is that what makes a bucket "food safe" is the release agent they use to allow the bucket to be released from the mold. Food-safe uses a, well, food-safe release agent; non-food-safe, not.

I wouldn't use a green or orange or any color bucket. The white ones are generally food safe. We have a local farm supply store here that sells buckets branded with their name, but they list the manufacturer. I went to their site to see what they said, and yes, the buckets are food safe. But they're white.

 

[GPP33]

My understanding is that what makes a bucket "food safe" is the release agent they use to allow the bucket to be released from the mold. Food-safe uses a, well, food-safe release agent; non-food-safe, not.

I wouldn't use a green or orange or any color bucket. The white ones are generally food safe. We have a local farm supply store here that sells buckets branded with their name, but they list the manufacturer. I went to their site to see what they said, and yes, the buckets are food safe. But they're white.

The seems a bit contradictory........ Is it the color or the release agent?

Use ones labeled food safe and give em a good clean to remove any residue of the supposedly food safe release agent which I still wouldn't want in my beer. If you think white helps you see if they are clean then choose white food safe buckets. Problem solved!

 

[mongoose33]

The seems a bit contradictory........ Is it the color or the release agent?

Use ones labeled food safe and give em a good clean to remove any residue of the supposedly food safe release agent which I still wouldn't want in my beer. If you think white helps you see if they are clean then choose white food safe buckets. Problem solved!

I'm just hedging my bet. Historically only white was food safe, and the distinction was the release agent. Now--supposedly--the colored buckets are also food safe, but I have a hard time with that. Not saying anyone's lying--I'm not saying that. It's just that I don't know what they're using as dyes or colorants in those colored buckets, and as long as I can verify the white ones *are* food safe, I'm not looking for different color schemes.

I know some people are resource-limited and so are trying to squeeze the nickel as much as possible; been there, raised kids, I get it. But there really isn't much difference in price between white buckets and, say, green buckets, and since with white buckets it's easy to see if they're dirty...

 

[SEndorf]

Perhaps I'm reading between the lines, but looking at the OP's post, these read like off flavors rather than infections.
Y'all have provided great advice re: sanitation, but I would take a look at ferm temps and other brew day issues.
Also, salt softened water is not ideal.
To really pinpoint the problem, you may want to try a few simpler recipes without the adjuncts. (peanuts, coconut, peanut butter, grape jelly, etc...)

 

[universalfrost]

just gonna say that PBW soak (long long soak) and ample use of starsan are needed possibly. also ditto on not being sure if you could truely sanitize those peanuts (other than bake them for a while in the oven beforehand and toss in some star san before hitting the fermenter)... that's what I do with my walnuts for a stout I make each year from black walnuts I collect from my tree...

 

[ccous]

Perhaps I'm reading between the lines, but looking at the OP's post, these read like off flavors rather than infections.
Y'all have provided great advice re: sanitation, but I would take a look at ferm temps and other brew day issues.
Also, salt softened water is not ideal.
To really pinpoint the problem, you may want to try a few simpler recipes without the adjuncts. (peanuts, coconut, peanut butter, grape jelly, etc...)

Agreed. I think a lot of times people think they have an infection when the beer just isn’t ready/cleaned up or has true off flavors due to poor process.

 

[El Nino]

Are you scrubbing the plastics? If so the scratches caused by it can harbor bacteria. You mentioned that in the batch you used the mr. beer fermentor that it was scrubbed thoroughly, and as far as I know they're plastic.

use a soft sponge for plastics, scrubbing is a no-no.

 

[the-adjunct-hippie]

Okay, there have been some questions, let me clear them up a bit.

"Scrubbing" was actually just a slang term for letting the cleanser soak a long time. I never use brushes of any kind, I simply soak and wipe down.

The off-flavors (minus the last one, watch and wait) are definitely infection. When you've got an oatmeal stout that tastes like a Destihl Gose, that's a problem.

Adjuncts are my life! (points to moniker)
I've made basic beers as well but it's much more fun to throw your spin on it. I have been successful with them in the past until this infection brush fire has occurred.

With the peanuts I'll be mashing them in only from now on. I don't know how I'm gonna do secondary with coconut because maybe you can't sanitize that either.


I'll be getting rid of those menards buckets and probably end up using white pails until I can afford a stainless steel fermenter.


Also to note, I got my order in the mail today and with it came 4 oz of IoStar. I'll be using that now to sanitize.

 

[universalfrost]

coconut you can bake like i mentioned before with the walnuts...

i do a coconut cream ale and use toasted coconut in the fermenter once the yeast do their thing at hit FG... if you dont want to toast it then soak it in vodka or some other alcohol (rum maybe) to help kill off the bacteria.

 

[GPP33]

coconut you can bake like i mentioned before with the walnuts...

i do a coconut cream ale and use toasted coconut in the fermenter once the yeast do their thing at hit FG... if you dont want to toast it then soak it in vodka or some other alcohol (rum maybe) to help kill off the bacteria.

I think waiting for the yeast to finish eating most of the food and generally making an inhospitable environment before adding things like fruit and nuts is a wise suggestion.

 

[the-adjunct-hippie]

Could the problem be that I am pitching the adjuncts at the same time as the yeast?
Maybe I just got lucky in the past.

 

[GPP33]

Could the problem be that I am pitching the adjuncts at the same time as the yeast?
Maybe I just got lucky in the past.

Yes, I think it raises your risk.

 

[jlinz]

I can't for the life of me figure this out. 3 of them were stouts, 1 of them was an IPA, and one of them I'm not sure is infected, but it's a little snappier than I'd like (PB&J beer).

I recently picked up some green Menards buckets (HDPE 2, food safe), brand new never used :

https://www.menards.com/main/menard...0-c-7113.htm?tid=-4242568597668123607&ipos=21

https://www.menards.com/main/housew...7-c-7113.htm?tid=-4242568597668123607&ipos=35


The first infected beer came from the top pail. The spigot leaked while we were on vacation and I deduced that if there was liquid coming OUT, there had to be bacteria going IN. I tossed it.

The second infected beer came from my Mr. Beer fermenter which has NEVER had a problem with infection. I chalked it up to not using enough sanitizer and vowed to use more next time.

The third infected batch came from another one of the pails posted in the top link. This one I could see a problem with as we had fruit flies in the house and I did catch a couple around the lid when I went to check the gravity.

The fourth and fifth ones though, I am really scratching my head.

Fourth batch was just dumped. It was made in the square bucket in the second link. Has a proper lid and everything. I sanitized the **** out of it. Filled it to the top with piping hot water, dumped my C-Brite in (which I have used since the beginning), let it soak for 30 minutes, dunked the lid in for 30 more minutes, sanitized everything I touched, and it still ended up infected. This was a big one. It was a chocolate-peanut butter-coconut stout. I re-used the bagged peanuts and bagged coconut from the boil, placed them in a sanitized dish and rinsed them with sanitized water before sticking them into the fermenter right after the wort and yeast were pitched. Awful vinegar flavor. I easily spent $25 on this 3 gallon batch. I am livid.

The fifth batch is a little more tart than I'd like. This was made in the Mr. Beer fermenter which I also scrubbed out thoroughly and soaked with C-Brite for an hour. It's a peanut butter jelly beer and the grape jelly flavor has just a little more acidity which I'm picking up faint infection - though I'm not 100% sure it is yet. The gravity reading on this one is 1.020 so it's almost finished. Lids were not opened or touched, buckets not shaken, nothing happened to these beers but sitting there fermenting at a comfortable 70 degrees.

US-05 was used in all batches. I've been much less careful in the past with sanitization and all my beers up until a month ago have turned out near perfect.

Is it these stupid green pails??

Also of note, these are all relatively small batches ~ 1.5 gallons in a 3 gallon or 4 gallon bucket. Too much headspace?

Everything I've told you is everything I've done. There is no mystery between the time I dump the wort into the sanitized bucket, pitch the yeast, and take a gravity reading 2 weeks out.

I'm going mad here. Our water softener is out of salt, and my wife suggested that was the problem. I can't for the life of me figure it out and it's gotta stop.

Help?

Thanks

It’s because you are an adjunct hippie! Haha, just kidding. I’m one too.

 

[aeviaanah]

I haven’t read the thread so forgive me if i make a fool of myself. Possibly it’s not an infection but something else?

 

[wepeeler]

The only infection I've ever had has been when I used C Brite. Toss it. Starsan ftw.

And yeast first, then add adjuncts.

 

[Clef051]

i think the problem is the c-brite is just a cleaner. Use that then use a sanitizer after it. I prefer starsan. It use to seem expensive, but a little goes a long ways. So a bottle last a long time, I think it is like 1oz in 5gallons of water and that last for a couple of months for me.