Wort saved for starter issue

[Steveski]

I have been an AG brewer since lockdown in 2020, generally brew about once a month and have had very good success. In May 2022 I bought a stir plate and 3L Erlenmeyer flask and moved into the world of yeast starters and yeast propagation.

Anyway, last month during a brew day, I decided to take 900ml of my first runnings (1.085) of a 30L batch of wort to save for use as my next starter. I boiled this in a saucepan on the hob until it reduced to 500ml (about 20 mins of boiling) and then put it in a very well sanitized PET beer bottle. I squeezed out all the air from the bottle and placed this in the fridge where it has stayed until now.

The idea being that I could dilute this back to just over 2L when needed, boil for 10 mins or so and use it as my 1.038 wort starter. I have just gone to use this and found the bottle is pressurized! I slowly unscrewed the lid and ¾ of the bottle came out as foam. The rest I tipped down the sink! I guess something has fermented this even though stored at 4C in the fridge.

I sanitized the bottle over quite a long time, certainly hours, with star san, shaking the bottle whenever I saw it whilst mashing the brew. My kitchen is spotless so I am amazed that something got to this. Anyone else had this problem? Was I pushing my luck storing concentrated wort for 5 weeks? This is the first time I have tried this method, I usually do a mini-mash on the day but was looking at scaling this up to do a complete mash and saving the wort in HDPE canisters to use over several months. However that seems like a bad idea now.

So sorry for the long post!

 

[peebee]

I see this loads on forums. I don't know where the illusion has come from, where you've picked it up, and how it's ever going to go away again. But I'll add my hopeless attempt to make it go away:

Star San is NOT a cleaner! It's a "contact" sanitiser. It must come into contact with the bugs to do them any harm. If your bottle hasn't been cleaned with an effective cleaner (and it needs to be effective when moderate temperatures of 50-60C will trash a PET bottle) then bugs will remain safe and sound under a film of grime that you cannot see!

Clean the bottle, rinse, and then (perhaps) use a contact sanitiser for a final rinse. It won't need soaking in the sanitiser, only contact for the allotted time (I think it's 1 minute for Starsan).

 

[xozzx]

Could you not freeze it? This would avoid any chance of unintended fermentation.

 

[Clarence]

Anyway, last month during a brew day, I decided to take 900ml of my first runnings (1.085) of a 30L batch of wort to save for use as my next starter. I boiled this in a saucepan on the hob until it reduced to 500ml (about 20 mins of boiling) and then put it in a very well sanitized PET beer bottle. I squeezed out all the air from the bottle and placed this in the fridge where it has stayed until now.

I presume you cooled the wort before putting it in the bottle and that the PET wasn't boiled, let alone autoclaved. Bottom line is that Starsan just isn't up to this job. It's not a steriliser!. You'd be safer using a vessel you can sterilise properly. Having said that, even if the wort in the PET had been ok, you would surly have boiled it and let it cool again before using it for your yeast starter, wouldn't you?

 

[samale]

I freeze the wort then boil it when needed

 

[Steveski]

I see this loads on forums. I don't know where the illusion has come from, where you've picked it up, and how it's ever going to go away again. But I'll add my hopeless attempt to make it go away:

Star San is NOT a cleaner! It's a "contact" sanitiser. It must come into contact with the bugs to do them any harm. If your bottle hasn't been cleaned with an effective cleaner (and it needs to be effective when moderate temperatures of 50-60C will trash a PET bottle) then bugs will remain safe and sound under a film of grime that you cannot see!

Clean the bottle, rinse, and then (perhaps) use a contact sanitiser for a final rinse. It won't need soaking in the sanitiser, only contact for the allotted time (I think it's 1 minute for Starsan).

Thanks for your response and everyone else with their replies.

I know exactly what you mean, however actually, I am one of those that are well aware that star san is only a sanitiser and not a cleaner or sterilizer. In hindsight, without sterilization, I think I was expecting too much to put the wort in such a vessel and expect it to be good after 5 weeks in a fridge. As others have said, you can't sterilize a pet bottle with heat as it will destroy the bottle. The bottle in question was brand new, rinsed thoroughly and sanitised as best as I could. I did not expect this outcome but I will just take this as a wake-up call as to how important sterilization is to storing wort. Unfortunately freezing it like others have suggested (and my preference) was not possible because our freezer is currently full of food. Therefore I will put the blame firmly on the Mrs for not leaving me with any space in the freezer.

I hope those that are discussing on another thread about putting wort in a cube and keeping it for weeks before fermentation are meticulous at cleaning and sanitising their storage vessels. How would you sterilize a HDPE container?

 

[Clarence]

I see this loads on forums. I don't know where the illusion has come from, where you've picked it up, and how it's ever going to go away again. But I'll add my hopeless attempt to make it go away:

Star San is NOT a cleaner! It's a "contact" sanitiser. It must come into contact with the bugs to do them any harm. If your bottle hasn't been cleaned with an effective cleaner (and it needs to be effective when moderate temperatures of 50-60C will trash a PET bottle) then bugs will remain safe and sound under a film of grime that you cannot see!

Clean the bottle, rinse, and then (perhaps) use a contact sanitiser for a final rinse. It won't need soaking in the sanitiser, only contact for the allotted time (I think it's 1 minute for Starsan

Soaking in a dilute solution of unperfumed bleach should do the trick and then rinse in metabisulphite solution to destroy the chlorine.
But isn't it easier keep a sachet of MJ malt extract in the fridge to use as and when it's required.

 

[peebee]

... How would you sterilize a HDPE container?

As homebrewers we don't actually "sterilize" anything, although some have a good go at it for yeast starter setups. It took the Americans to come along a few years ago and teach us the difference between "sterilize" and "sanitize". Previously we "sterilised" everything, but we didn't: The blokes amongst us were a bit uncomfortable with the word "sanitise" ... I can't think why ...

The Americans also reminded us how to spell the word (with a "z" not an "s"), but many still won't believe it.

This (active) thread is about using HDPE, and there's mention of keeping unfermented wort for two years under these conditions. Although I've only dared for two days:

https://www.thehomebrewforum.co.uk/threads/no-chill-in-cube-question.103203/

 

[peebee]

But isn't it easier keep a sachet of MJ malt extract in the fridge to use as and when it's required.

@Clarence! Last time we spoke you promised to stick me in your ignore list; have you been peeking?

Anyway, Clarence's advice is for anyone else. I do only use fresh malt extract for yeast starters, hence my advice above is "generic" (i.e. I don't attempt to keep wort in the fridge for Yeast Starters; but I might start for this "no-chill" caper?).

 

[Agentgonzo]

If you have a sealable glass jar you could oven it, then pour in the boiling wort and seal the lid. My wife does this when making jam.

I can't guarantee it will work, and if it ferments you'll end up with a glass grenade.

If you have a pressure cooker, you could fill the jar, then pressure cook for about half an hour. That will probably be the best any of us can come to sterile.

Best option is to negotiate some room in the freezer. Doesn't have to be a bottle. Reused and washed take away containers stack wonderfully

 

[Steveski]

If you have a sealable glass jar you could oven it, then pour in the boiling wort and seal the lid. My wife does this when making jam.

I can't guarantee it will work, and if it ferments you'll end up with a glass grenade.

If you have a pressure cooker, you could fill the jar, then pressure cook for about half an hour. That will probably be the best any of us can come to sterile.

Best option is to negotiate some room in the freezer. Doesn't have to be a bottle. Reused and washed take away containers stack wonderfully

I now think the same principal applies to storing wort. Sanitise is fine for brewing (fermenting wort) but not for storing wort, that is more critical. It needs to be stored in a sterile container preferably in one with low oxygen permeability like the jam.. Obviously my pet bottle was neither of those!

I guess its time to invest in some good old fashioned Kilner jars (or use less sterile containers and buy a spare freezer) if I want to continue making the starter ahead for the following brew.

 

[peebee]

... The Americans also reminded us how to spell the word (with a "z" not an "s") ...

But I'm not going totally soft in the head (I'd done that years ago) ... "z" ... that's a "zed" not a "zee"!



Anyway, enough of that. I'm probably reminding @Clarence why he chucked me in his ignore list in the first place.

... How would you sterilize a HDPE container?

Didn't answer that bit. I use sodium percarbonate, the so-called oxygen bleach, (about 10-30g per litre, 40-50°C), but some don't care for its use like that (cleaner, sanitiser and deodoriser). I'm personally not keen on bleach, but that's probably because I'm too old to think of "thin bleach" as anything other than "cheap bleach". I would have tried "thick bleach" which is near enough impossible to remove then stench of chlorine off anything it's used on. Propriety cleaners like VWP can be similar when it comes to rinsing off the chlorine stench left on plastics. You need to be careful with Metabisulphite too (don't overdo the strength of it).

Some use iodine preparations (like Iodophor), but they do stain plastics and are possibly as difficult to remove the stench after using it?

 

[Tess Tickle's Brewery]

Thanks for your response and everyone else with their replies.

I know exactly what you mean, however actually, I am one of those that are well aware that star san is only a sanitiser and not a cleaner or sterilizer. In hindsight, without sterilization, I think I was expecting too much to put the wort in such a vessel and expect it to be good after 5 weeks in a fridge. As others have said, you can't sterilize a pet bottle with heat as it will destroy the bottle. The bottle in question was brand new, rinsed thoroughly and sanitised as best as I could. I did not expect this outcome but I will just take this as a wake-up call as to how important sterilization is to storing wort. Unfortunately freezing it like others have suggested (and my preference) was not possible because our freezer is currently full of food. Therefore I will put the blame firmly on the Mrs for not leaving me with any space in the freezer.

I hope those that are discussing on another thread about putting wort in a cube and keeping it for weeks before fermentation are meticulous at cleaning and sanitising their storage vessels. How would you sterilize a HDPE container?

I know someone won't be happy with this and shoot me down, but on the rare occasion I use a pet bottle and want to clean it, I brim it with purple line cleaner and leave it to soak for an hour. Shifts everything. Obviously rinsing very well with cold water afterwards and then the starsan. Glass is preferred though for me.

 

[starseeker]

I find VWP great , cleans and sterilises and it is very reasonably priced .

 

[RoomWithABrew]

I wouldn't have bothered to boil it down to 500ml either just bottled and froze it. I tend to just use the final runnings for keeping in a pet bottle as next starter. It tends to be around 1.030
I squeeze it for expansion space before freezing it. Then reboil and use that as the base for the starter.
Some evidence out there that microwaving a container to boil the liquid in it may be as effective as autoclaving. Trouble is this is only suitable for my 500ml Erlenmeyer flask.

 

[MashBag]

Could you not freeze it? This would avoid any chance of unintended fermentation.

Absolutely. Done that loads of times.. Even with yeast, to restart later (and yes it does).

For everything there is caustic

 

[peebee]

... Sanitise is fine for brewing (fermenting wort) but not for storing wort, that is more critical. It needs to be stored in a sterile container preferably in one with low oxygen permeability like the jam.. Obviously my pet bottle was neither of those! ...

Oh, oh. We're kicking off another of those extreme cleaning/sterilising threads. Already getting murmurs to casually wield skin dissolving stuff (potentially like Lye).

Sterilising sounds great, I think it's a three nines (99.999%) effective process? But that is un-necessarily extreme, probably best saved for hospital operating theatres and some laboratories. "Sanitising" (one nine, 99.9%, if I remember rightly?) is probably far more than the majority of us achieve and is more than adequate. Beer-brewing at home is not a life-or-death situation.

I read your description of "sanitising" your PET bottle and you, like hordes of other homebrewers, simply weren't following the instructions for the sanitizer you were using ("Starsan").

You'll be fine with a PET bottle. Just get a suitable cleaner, perhaps a sanitizing rinse aid like "Starsan", and follow the instructions! If it works like magic, it probably needs magic to work ... sadly, magic doesn't really exist.

 

[Steveski]

Oh, oh. We're kicking off another of those extreme cleaning/sterilising threads. Already getting murmurs to casually wield skin dissolving stuff (potentially like Lye).

Sterilising sounds great, I think it's a three nines (99.999%) effective process? But that is un-necessarily extreme, probably best saved for hospital operating theatres and some laboratories. "Sanitising" (one nine, 99.9%, if I remember rightly?) is probably far more than the majority of us achieve and is more than adequate. Beer-brewing at home is not a life-or-death situation.

I read your description of "sanitising" your PET bottle and you, like hordes of other homebrewers, simply weren't following the instructions for the sanitizer you were using ("Starsan").

You'll be fine with a PET bottle. Just get a suitable cleaner, perhaps a sanitizing rinse aid like "Starsan", and follow the instructions! If it works like magic, it probably needs magic to work ... sadly, magic doesn't really exist.

Just a couple of points then from me but I really don't want to create an argument here....

You say "Sanitising" (one nine, 99.9%, if I remember rightly?) is probably far more than the majority of us achieve and is more than adequate. Beer-brewing at home is not a life-or-death situation."
My point is that sanitising is fine for brewing, but here I am talking about food preservation. In brewing we only need 99.9% because the yeast will soon overpower any remaining bugs in the fermenter and starve them of oxygen so they can't multiply (assuming suitable pitch rate is observed). For food preservation, any small amounts of bacteria would be free to multiply if oxygen is available and this could lead to the wort being spoilt over a moderate length of time.

You also said "I read your description of "sanitising" your PET bottle and you, like hordes of other homebrewers, simply weren't following the instructions for the sanitizer you were using ("Starsan")."
Apart from not cleaning my brand new coopers pet bottle with something like PBW or VWP what did I not follow regarding the Starsan instructions?

 

[MashBag]

Oh, oh. We're kicking off another of those extreme cleaning/sterilising threads.

Yup. I thought that.

 

[peebee]

Apart from not cleaning my brand new coopers pet bottle with something like PBW or VWP what did I not follow regarding the Starsan instructions?

Tut, tut. But I'm not blaming you, how can I, there are folk on this forum who believe it has some magical cleaning power yet the "limitations" are repeated endlessly in discussions on this site. Five Star aren't saints about it and don't perhaps emphasis the limitations enough, but they don't not mention it. The words on my bottle (a big one) are getting a bit obscured but I can read the first line:

Directions for use: use as a final rinse ...

Humm, could have been clearer. On their Web site:

No confusion there. But perhaps they could mention the reasons?

They don't discuss its mechanism, which would help some people understand its workings: The active principle is Dodecyl benzene sulfonic acid. Its a surfactant that will disrupt the fatty membranes that hold a bug (single cell beasty) together ... so wrecking them. Also helps you understand the scale its working on and how an utterly invisible film of grime is quite enough for a bug to hide fom the stuff.

As surfactants go, its quite unusual because it functions in acidic conditions, more in keeping with brewing environments (it might only be applied as a light spray).

Some argue its old-fashioned and ineffective. Perhaps, but we're not expecting it to be faced with the newest mega-bugs available. I don't think it got a rating (considered even) for COVID19!