I feel stupid every time I make a starter

[IslandLizard]

** Freezing is not 100% protection from Botulism. 240F is the only real protection (pressure canning).

Indeed, it doesn't kill the bacteria, only pressure canning (@240F and over) does.

But freezing (wort) will inhibit the bacteria from forming spores, and any spores present from growing, thus preventing botulinum toxin from being formed. The frozen wort should be reboiled then chilled right before use.

Now letting wort sit out there for a few days at room temps or higher, without pitching yeast and starting fermentation, is always risky, especially in low oxygen environments.
Chilling (wort) to refrigerator temps (34-38F) will slow the toxin forming process down, but may not entirely stop it. So it depends on how long it's being stored in the fridge.

https://www.cdc.gov/botulism/general.html

 

[mendelec]

My small addition to the Mason jars in the pressure cooker/canner conversation is that I usually grow my starters out in 2 steps from the frozen stocks, so I also keep repurposed baby bottles that have about 250ml of starter in them for the first round out of the freezer. It's also handy to have smaller amounts around for when opportunity strikes to culture something new from a beer you find fascinating.

 

[DavidWood2115]

So this is probably overkill, but has anyone considered sterilizing fresh wort in a pressure-rated conical/unitank, then storing it in a sanitized corny keg for later use? My Spike CF10 is rated to 15psi, the same as all home pressure cookers. It is questionable that Spike's heating pad would be sufficient to heat the wort to 250F (due to radiant heat loss), but you could stick a standard e-brewing heating element in one of the TC ports or hook up a RIMS tube to get ample power. You would need to provide sanitary make up "air" when you cool the wort, to prevent collapsing the fermenter. And you would might want to use nitrogen gas, since the oxygen in air wouldn't be great for your wort and CO2 would lower the pH.

A bit of extra gear, but one 5 (or 10) gallon batch would provide starter wort on tap for at least several months.... And it wouldn't even need to be refrigerated.

 

[mendelec]

Now that's an interesting thought and I do have couple spare kegs about. Hmmm... At that volume, I'd just be inclined to mash a batch and boil it long enough to not worry, since I don't have anything that I can use to pressure sterilize a full volume pressure. Just boiled though, I'd still worry. And, I'd use the CO2 precisely for that reason. Botulism spores can survive boiling, but don't thrive in acidic media. The excess CO2 will blow off pretty fast in the flask. Probably won't ever do it, but it is an interesting thought.

 

[IslandLizard]

I'd just be inclined to mash a batch and boil it long enough to not worry,

It's not the length of time the wort is boiling (which is around 212F). It's the higher temp (240-250F, which can only be achieved under pressure) and the time it spends there that sterilizes it.

 

[mendelec]

Indeed. Although at the level of pasteurization, there is a time and temp aspect, which is to a certain extent, how one can have a no boil brew and not die. But, neither pasteurization temps nor boiling will touch bacterial spores like C. botulinum. And, it isn't the pressure either. It's that the pressure allows you to achieve a temp capable of destroying C. botulinum spores.

But, as I noted, C. botulinum doesn't grow out in acidic conditions. The different food canning processes largely reflect the acidity of the material being canned, with non-acid foods usually needing the higher temp achieved by pressure canning (I'm oversimplifying). In brewing, the acidity generated by the brewing/fermentation process (along with the alcohol and the hops) and that we overwhelm the system with a ridiculously large inoculum of yeast that keeps the nasties at bay. You have a similar phenomenon going on with yogurt making, where you can get away with mere pasteurization, because you toss in enough of an inoculum where the bacterial fermentation gets the pH down to a safe level in a relatively short amount of time.

But, I wouldn't be comfortable using (un-sterized) wort that had only been boiled at atmospheric pressure and then stored, no matter how long it had boiled. I do have a doctorate in microbiology, but it's been a very long time since I've been at the bench and botulism isn't my idea of a fun time. I'd have to look up what the pH needs to get down to, in order to inhibit sporulation. It's possible and even likely that letting it carb would get enough CO2 in there to be safe, but that's not a gamble I'd take without reading up on it.

Having a keg of starter lying about is an interesting thought, but it may just not be practical to do it safely. Even if I had a kegged starter I felt good about, I'd still be very concerned about safely dispensing some without contaminating the rest. Fermented foods are a sh** ton more stable and resistant to contamination than unfermented and mere sanitation like we use routinely just ain't gonna cut it.

Now that I think about it, I just have no idea how I'd sterilize a keg to be food safe, let alone keep it that way, in an environment where C. botulinum spores could sporulate. I think I'm chalking this one up to an interesting theoretical discussion, but I'm not about to risk an ugly death for a bit of convenience. I'll stick with pressure canned (autoclaved) single use containers of sterile wort.

 

[Bassman2003]

pH of 4.6 or below is where the safe zone begins.

 

[pvtpublic]

Bassman and the lizard are right. But if you're still concerned, boiling for at least 20 minutes after taking it out of storage will denature the toxins produced by bacteria. That's according to a state ag report, please don't make me dig that up, you can find it just the same as I did.
I pressure can at the same time I start the boil, it's really not all that difficult, and I'm lazy, which doesn't explain why I do all grain. But I digress, surprise surprise.

My method, which might not work for you, but may spark an idea in your grey matter; my mash is super efficient, more so than the recipes I brew. So I run the first 4 gallons into my kettle, the next 2 into another container, and another 3 into another. I do my gravity readings and blend the wort until I get my desired preboil gravity. If you don't know how to figure that, get "Designing Great Beers" or just Google it, whatever. Whatever I have left, I adjust with water or DME to hit 1040, then I pressure can. Whatever doesn't fit into quart jars, my kid drinks as a treat.

Well, I hope that help some poor old soul out there somewhere...

 

[BigDave1303]

To avoid clumping, mix the DME with cold water then bring to a boil & cool ready for the yeast.

 

[govner1]

Of course, you could always use a can of Propper and avoid the boiling , etc.
It’s a great product.

 

[duncan.brown]

Of course, you could always use a can of Propper

For comparison, a pressure canner costs somewhere in the region of $400. Add $50 for mason jars and lids, and that $450 buys you 128 cans of Proper starter. If you brew every other weekend, that's about 3 or 4 years worth of starter (assuming your starters range between 1 and 3 liters per batch). Five years if you only ever make 1 liter starters. Factor in the time it takes to pressure can (for me, two lost brew days a year) and that turns out to be a pretty cost-effective solution.

 

[Bassman2003]

I purchased my pressure canner for $70 new (quite a few years ago). They have gone up some but you do not need a fancy one. Presto is the brand I have. Holds 7 large mason jars. 12 mason jars are about ~$10-$12. You could easily pick up a used one as they are simple devices.

 

[duncan.brown]

Good point on the cost. My All-American is overkill for starters, but I also use it as an autoclave.

 

[Bassman2003]

What is the difference when used as an autoclave compared to other canning?

 

[DavidWood2115]

Now that I think about it, I just have no idea how I'd sterilize a keg to be food safe, let alone keep it that way, in an environment where C. botulinum spores could sporulate. I think I'm chalking this one up to an interesting theoretical discussion, but I'm not about to risk an ugly death for a bit of convenience. I'll stick with pressure canned (autoclaved) single use containers of sterile wort.

Good point on sterilizing the keg. Another alternative would be to make or buy a corny lid with a TC port and simply sterilize the fresh wort in the keg, which is pressure rated for far more than the necessary 15psi. You would need to leave the heating element inside to be safe, but I think that should be fine. Alternatively you might be able to find an external heat wrap that would do the trick. You would still need to figure out how to prevent any contamination from entering the keg through the gas and/or liquid ports during use, which would be enough to keep this theoretical (at least for me).

 

[fuzzybee]

Thank, everybody. For my second beer, I used a saucepan for my starter boil, and then added it to my flask. starter turned out fine, and no clumpy DME. I may give Propper starter a go for my next beer.

 

[IslandLizard]

I may give Propper starter a go for my next beer.

Proper has gone down somewhat in price the past year or so. It used to be $6 for a 16 oz can, now it's $3.75, ($15 for a 4-pack, MoreBeer).

DME has gone up quite a bit lately, it's as high as $6 a pound now if bought in 3 pound bags (MoreBeer). My LHBS sells it for $5.33 a pound ($16 for a 3# bag), while it used to be $4 a pound.

Now 1 pound of DME will make 4.5 liter of 1.037 starter wort, or $1.33 a liter (MoreBeer pricing). Using Proper will run you $3.75 a liter, a difference of $2.42 a liter,* almost 3x the cost compared to using DME, just for the convenience.
Not a big issue when you brew once in a while, even once or twice a month, but if you brew more often, or propagate yeast for keeping or sharing, or brew larger batches, it adds up.

* Mind, one liter is not quite the amount needed for most pitches, 1.6-2 liter starters are more common for 5 gallon batches of ale. That allows one to ranch some too. So the price difference between starters made with Proper and DME becomes more significant, and double that, in case of Lagers.

 

[duncan.brown]

What is the difference when used as an autoclave compared to other canning?

Longer times, so I feel a bit more comfortable with the All-American on my stove than one of the cheaper canners.