Kegging Starter Wort?

I've been making batches of starter wort from 2row and canning it in half gallon jars. It's worked well for a while, but canning only 4 jars at a time is a hassle. I'm now brewing more frequently and in larger batch sizes so making enough wort to keep up is actually eating into my brewing schedule.

I'd like to start kegging my starter wort and I'd like to know if anyone else is doing this.

I'd mash and boil a batch of 2row to 1.035, knock out straight into a sanitized 5 gallon corny, and seal immediately. The cooling wort will start to pull a vacuum so I'll attach CO2 to avoid pulling contaminated air in. I was also thinking i could use one of those inline 1micron filters attached to a length of hose on the the gas post. Once it's cooled I'll hit it with CO2 and throw it in the keezer.

Did I miss anything? Can I keep it at room temp once pressurized? Do I need to worry about botulism? How long do you think it will keep?

This is a truly great idea man. Treating it as a no-chill batch by dumping in the boiling wort would help sanitize to the furthest degree imo. I would only be worried about the tap, those would be hard to keep sanitized long term I would think, to the level of a starter anyways.

I think room temps would be good for months but a year or so I would refrigerate it.

A sci guy needs to chime in about the botulism, I'm merely an artist

I pressure can wort, about 1 gallon at a time of 1.080 wort. I do a bunch of little pint jars - so that when I need a starter I can take one out and dilute 50% with water and get my 1.040 starter wort.

I trust kegging for beer that is going to stay cold until it gets to my glass, I don't know that I would keg starter wort. I just don't trust it that much to risk future batches to a desire to shave some time. plus you are bringing other variables into play - the beer lines from which the wort will pour, the spout, the fittings.

No doubt dude that your sanitation must be meticulous as said above, completely forgot about the fittings!

I'd really be concerned with botulism. Not sure if wort is similar to vegetables, but if not canned properly you can have a serious problem on your hands. From what I've heard there are no real signs that food goods are infected with botulism. It however can cause very serious issue if contracted. I wouldn't do it.

I guess you could keg it, keep it cold, then boil it again after you pour it.

that seems to defeat the purpose of trying to save time though.

I wonder if there is a way to freeze starter wort?

I freeze second running wort frequently. I pour into mason jars, leave some headspace and thaw in the fridge a day or so before boiling. Then boil as usual in my flask.

runningweird said:

I guess you could keg it, keep it cold, then boil it again after you pour it.

that seems to defeat the purpose of trying to save time though.

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If botulism toxins get into it, no amount of post-boiling will kill the toxins. Boiling would kill the spores but would not remove the resulting toxins.

M_C

I love the thought as I don't own canning equipment and have been considering doing the 'wort in advance' thing for my starters as well. Sanitation on the out post would be key but could easily be managed I would think. Not sure why there is an increased risk as bugs don't crawl - and if you are going into a sanitized keg with boiling wort you are effectively sanitizing everything. Any other thoughts as I think the OP is on to something here!

makomachine said:

I love the thought as I don't own canning equipment and have been considering doing the 'wort in advance' thing for my starters as well. Sanitation on the out post would be key but could easily be managed I would think. Not sure why there is an increased risk as bugs don't crawl - and if you are going into a sanitized keg with boiling wort you are effectively sanitizing everything. Any other thoughts as I think the OP is on to something here!

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Boiling temps don't kill everything. That's why you have to pressure can vegetables and things. Botulism is real and can't be killed by boiling.

pickles said:

Boiling temps don't kill everything. That's why you have to pressure can vegetables and things. Botulism is real and can't be killed by boiling.

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Just read up on it more and understand it better now. Looks like a pressure cooker is in my future.

Misplaced_Canuck said:

If botulism toxins get into it, no amount of post-boiling will kill the toxins. Boiling would kill the spores but would not remove the resulting toxins.

M_C

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IIRC, you've got that exactly backwards. Boiling (at normal pressure) won't kill the spores, but will denature the toxin (need 185F for that). To kill the spores, you need 250F, which you can get to by boiling under pressure (pressure canner).

So, while you could boil your wort and store in kegs, you still should boil again once you're ready to use that wort in a starter.

Here's a bunch more great info from a gardening forum:

The toxins are produced by the bacteria when the bacteria are multiplying. The bacterium, Clostridium botulinum cannot grow in the presence of oxygen. It can grow in CO2, at least low levels, I would have to look up how high the level they can tolerate.

The spores are produced by the bacteria when they are in conditions where they cannot grow. The spores are an "alternative life form" for the bacteria - a way for the bacteria to go into a dormant state that is resistant to many environmental assaults.

The spores are incredibly resistant to a large number of conditions. Viable spores have been recovered from ceramic pots that are thousands of years old. For a very interesting story about another closely related spore, Bacillus anthracis, causative agent of anthrax, do a web search for "Gruinard Island".

Spores can survive 5 hours in boiling water, but can be inactivated in 4 minutes in an autoclave which provides pressurized steam (121°C, 15 psi). Yes, acid and radiation affect spores and in combination can inactivate them, but the conditions required are very stringent.​

I had this discussion about the difference between boiling and canning and as worts ph is not low enough to keep mold at bay you have to can it for long term storage. You could test your methid witha boiled can and see if it goes off?

Clem

Not to get away from the kegging question, but I want to make a couple gallons of wart to can by mashing some 2 row. For yeast starters.
Can I just can it after the mash and skip the boil? The canner boils it at 250 right?
If I have to still do the boil step how long?
Thanks

Relax, don't worry, have some botulism.

I prefer freezing starter wort, then thaw and boil when I make a starter. PP tubs with snap lids work well.

nate456789 said:

Not to get away from the kegging question, but I want to make a couple gallons of wart to can by mashing some 2 row. For yeast starters.
Can I just can it after the mash and skip the boil? The canner boils it at 250 right?
If I have to still do the boil step how long?
Thanks

Click to expand...

no as long as you get to your desired gravity the wort will boil inside the canner - which should be done for at least 20-30 minutes to make sure everything is up to temp and pressure. so you don't need to boil beforehand.

passedpawn said:

IIRC, you've got that exactly backwards. Boiling (at normal pressure) won't kill the spores, but will denature the toxin (need 185F for that). To kill the spores, you need 250F, which you can get to by boiling under pressure (pressure canner).

So, while you could boil your wort and store in kegs, you still should boil again once you're ready to use that wort in a starter.

Here's a bunch more great info from a gardening forum:

The toxins are produced by the bacteria when the bacteria are multiplying. The bacterium, Clostridium botulinum cannot grow in the presence of oxygen. It can grow in CO2, at least low levels, I would have to look up how high the level they can tolerate.

The spores are produced by the bacteria when they are in conditions where they cannot grow. The spores are an "alternative life form" for the bacteria - a way for the bacteria to go into a dormant state that is resistant to many environmental assaults.

The spores are incredibly resistant to a large number of conditions. Viable spores have been recovered from ceramic pots that are thousands of years old. For a very interesting story about another closely related spore, Bacillus anthracis, causative agent of anthrax, do a web search for "Gruinard Island".

Spores can survive 5 hours in boiling water, but can be inactivated in 4 minutes in an autoclave which provides pressurized steam (121°C, 15 psi). Yes, acid and radiation affect spores and in combination can inactivate them, but the conditions required are very stringent.​

Click to expand...

Thanks for the correction.

M_C

nate456789 said:

Not to get away from the kegging question, but I want to make a couple gallons of wart to can by mashing some 2 row. For yeast starters.
Can I just can it after the mash and skip the boil? The canner boils it at 250 right?
If I have to still do the boil step how long?
Thanks

Click to expand...

you can do this however you end up canning all the hot break, I boil mine first and let it cool in the pot before decanting from the hot break and the pressure cook that. you will have a small amount of second hot break form however it is significantly less.

Clem

Thanks for all the replies and sorry for disappearing for a while; this has become a great thread!

I've done a little research and I think I might be able to make this work. here's my evidence from this post:

chase said:

The botulin toxin producing bacteria is inhibited at a pH < 5.5. Beer is typically about about pH=4.0-4.5. Since pH is logarithmic, that means beer is over ten times too acidic for C.botulinum to grow.

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and from Wikipedia:

Growth of the bacterium can be prevented by high acidity, high ratio of dissolved sugar, high levels of oxygen, very low levels of moisture or storage at temperatures below 3°C (38°F) for type A. For example in a low acid, canned vegetable such as green beans that are not heated hot enough to kill the spores (i.e., a pressurized environment) may provide an oxygen free medium for the spores to grow and produce the toxin. On the other hand, pickles are sufficiently acidic to prevent growth; even if the spores are present, they pose no danger to the consumer. Honey, corn syrup, and other sweeteners may contain spores but the spores cannot grow in a highly concentrated sugar solution.

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The plan is to keg boiling wort as described above, but boil it to 1.080 as runningweird does, and adjust the pH with brewing salts to 4.0. The the low pH will prevent any spores from activating, just like in finished beer and the canned pickles. I also have fairly high sugar concentration, although I'm not sure if it's high enough to be helpful.

I'll take extra care to scrub the threads on the posts of the keg and maybe even run boiling water through the posts as they're attached before filling the keg.

When I make a starter I'll add the correct amount of 1.080 wort to an equal amount of sterile, pH adjusted water, so i'll have a 1.040 wort that is pH friendly to the yeast.

Proceed as normal, no botulism.

What do ya think?

Seems like the real issue would be bacterial contamination when transferring it out of the keg....

Nifty concept here...

The answer seems slightly simple to me... looking at No Chill (which has been proven to be safe especially by our aussie friends) If you can seal wort in a plastic cube for several months before you ferment it why the heck could you not keep it in an oxygen free keg for several months before you use it as a starter...?

The only question I have is how does fermenting CO2 enriched wort work? Would you have to shake out the carbonation before you aerate and pitch to make your starter?

I personally think this is a cool idea if it works and doesn't get too complicated.

emjay said:

Seems like the real issue would be bacterial contamination when transferring it out of the keg....

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Referring back to the original post... The OP says canning the wort is taking too much time for him. If you are only connecting the liquid post to make a starter every time you brew, it would be taking SIGNIFICANTLY less time to clean and sanitize a beer line than can several jars of wort.

I'm actually not all that concerned about contamination during transfers. As long as the the posts are clean and sanitary when you put them on then it just becomes an issue of making sure your liquid QD is clean when making that starter. I'm sure I'd take extra precautions before and after transfers, up to and including the filter i mentioned in the OP for gas in.

H-ost, I'm not familiar with No Chill, so I'll have to do some reading, but I can probably take a guess at what it's all about

As for the CO2 question, I don't think it will be an issue. Between mixing the wort with H2O and oxygenating with an air stone there wont be much CO2 left.

Finally, in the bit of research I did regarding botulism, I never got the impression that it's a serious, SERIOUS, risk. OF COURSE it's out there, and should be taken very seriously (which I have), but I didn't come across horror story after horror story of canning gone wrong and people dying from botulism. Obviously precautions must be taken, and I feel confidant that I've mitigated the risk with the plan I've outlined.

I bit the bullet this past weekend and mashed up a bunch of older base malt due to the immediate need for some starter wort, but once that runs out I'll be ready to give this a go and I'll definitely report back.

I really doubt you'll be able to keep it from going off in some fashion. At the very least it's going to grow all sorts of mold.

Why mold?? If it is completely sanitized by the boiling wort when it goes in there and it is completely sealed why/how would anything be growing in there?

SenorWanderer said:

When I make a starter I'll add the correct amount of 1.080 wort to an equal amount of sterile, pH adjusted water, so i'll have a 1.040 wort that is pH friendly to the yeast.

Proceed as normal, no botulism.

What do ya think?

Click to expand...

So where are you going to get the sterile water? I have to pressure can mine. If you have to pressure can water to add to the kegged wort that doesn't sound like much of a time saver to me.

Misplaced_Canuck said:

If botulism toxins get into it, no amount of post-boiling will kill the toxins. Boiling would kill the spores but would not remove the resulting toxins.

M_C

Click to expand...

Not that I want to test it or know anything about this subject, but wiki appears to give a somewhat different answer:

Botulism can be prevented by killing the spores by pressure cooking or autoclaving at 121 °C (250 °F) for 3 minutes or providing conditions that prevent the spores from growing. The toxin itself is destroyed by normal cooking processes - that is, boiling for a few minutes.

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Here's the article: Botulism - Wikipedia, the free encyclopedia

But your point is well taken, doing a regular (non-pressurized) boil isn't good enough.

H-ost said:

Why mold?? If it is completely sanitized by the boiling wort when it goes in there and it is completely sealed why/how would anything be growing in there?

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Unless it was autoclaved and all transfer done with sterile (clean air hood etc) technique, a container of nutritious, sweet, and oxygenated liquid.... well, it's only a matter of time.

H-ost said:

Why mold?? If it is completely sanitized by the boiling wort when it goes in there and it is completely sealed why/how would anything be growing in there?

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"Completely sanitized" is a bit of an oxymoron, actually.

Like, 'completely partway there.'

Yes, I realize that. I obviously could not use the word sterile but could not think of a better way to explain a closed environment that has had the entire interior hit with 220+ degrees with hardly any oxygen (boiling removes the majority of it from the wort thats why we have to aerate before pitching, when using cubes you try to squeeze out the extra air, and with this idea you would purge it with CO2).

But please explain to me how a plastic cube won't grow mold when left for anywhere between 2 weeks - 4 months but a SS keg would. I looked to try to find a link so I could back up this statement but I'm at work and you have to be a member of the aussiehomebrwers.com to use their search... I will try to find one later but even our own "Exploring No-Chill" thread claims saving cubes for up to 6 weeks with no issue whatsoever.

I personally have only kept wort in a cube up to just about 2 weeks. I do believe I have read somewhere of someone boasting several months, this I should probably try myself just for the sake of knowing but now I'm really starting to contemplate buying a 2.5 gallon keg and kegging my starter wort so I can see first hand how this will work.

Botulism isn't something i'd want to mess with, look into canning your wort.

Pressure cookers come in handy for all kinds of things, and they aren't that expensive. Mason jars are extremely easy to come by. Can a good number of jars at a time, stick them in the fridge, and you'll have starter wort for a long while.

H-ost said:

Yes, I realize that. I obviously could not use the word sterile but could not think of a better way to explain a closed environment that has had the entire interior hit with 220+ degrees with hardly any oxygen (boiling removes the majority of it from the wort thats why we have to aerate before pitching, when using cubes you try to squeeze out the extra air, and with this idea you would purge it with CO2).

But please explain to me how a plastic cube won't grow mold when left for anywhere between 2 weeks - 4 months but a SS keg would. I looked to try to find a link so I could back up this statement but I'm at work and you have to be a member of the aussiehomebrwers.com to use their search... I will try to find one later but even our own "Exploring No-Chill" thread claims saving cubes for up to 6 weeks with no issue whatsoever.

I personally have only kept wort in a cube up to just about 2 weeks. I do believe I have read somewhere of someone boasting several months, this I should probably try myself just for the sake of knowing but now I'm really starting to contemplate buying a 2.5 gallon keg and kegging my starter wort so I can see first hand how this will work.

Click to expand...

If the cubes work as well as you've indicated, I do think it can probably be stored for an extended amount of time. However, even a cube should show signs of infection eventually... I'm not sure how quickly he plans to use a whole keg of starter wort, but I doubt there are many brewers that could use it quickly enough. And while botulinum is unlikely, it's still possible, and I wouldn't be willing to take that chance.

Also, I mentioned earlier that I felt the biggest infection risk lied in transferring it out of the keg. You responded with...

H-ost said:

Referring back to the original post... The OP says canning the wort is taking too much time for him. If you are only connecting the liquid post to make a starter every time you brew, it would be taking SIGNIFICANTLY less time to clean and sanitize a beer line than can several jars of wort.

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So the fact that you're using boiling wort to sanitize the keg (which you're using to support your position) is almost rendered moot, since you can't do the same for the post/line/tap.

Not to mention that once you pour your first batch of starter wort, you start exposing the keg to even more bacteria. A finished beer has alcohol and hops to protect it from the fairly small amounts of bacteria that are introduced this way, but it really doesn't take much for wort to reach the tipping point.