Starter boils over in the autoclave. Is there a fix?

[Charlie]

It really is dangerous to can wort after only boiling it. While the probability of actually contracting botulinum spores is somewhat low, it doesn't matter. That shit can kill you. Don't mess around. Pressure cooker or don't do it.

That is an excellent observation! The botulinum toxin (not the organism) is destroyed by heating to more than 85 °C (185 °F) for longer than 5 minutes, but that doesn't apply to a starter because the starter is introduced directly into the cooled wort.

Charlie Papazian stated in The Complete Joy of Homebrewing that nothing harmful would grow in beer: You weren't going to get sick no matter how bad it was. Are there any recorded instances of botulism toxicity (or any other illness) from beer? I have never heard of one.

Charlie

[Ozwald]

The whole idea of storing green wort has always sounded pretty ridiculous to me, even as someone who was going through several gallons of the stuff every week at one point. For the average user who's just brewing (as opposed to playing around with yeast, as I was doing with it) DME is relatively cheap & it only takes 15 minutes to whip up a batch for a starter.

Secondly, putting it in an autoclave, unboiled, just sounds like an extra bad idea from the get-go. While DME doesn't go through a true hot break, you're still denaturing proteins to some extent... the point being you're altering the solution chemically, not just sanitizing it.

Thirdly, slants & starters are not the same thing. One of the reasons bad shit can't grow in beer (note that I said beer, not wort) has to do with the yeast colony having "control" over the medium. Bad shit can't get a foothold as long as the yeast or yeast/bug colony is happy, healthy, and has control over the medium. Slants are a different beast all together. It's true that nothing harmful can grow in beer, but that is inoculated & fermented beer. Not green wort.

Is there a fix? Yes. Go buy some DME & make the starter wort as you need it. Don't mess around with canning shit unless you have a pressure canner & are able to use it correctly - the probability of contracting botulism isn't as low as you might think. Actual cases are only low because your average person doesn't mess around with food preservation & the few who do understand the risks of doing it wrong. Using an autoclave for something like this just sounds like a solution looking for a problem... and a poor solution at that.

[NateBrews]

+1 to all that

I looked at canning wort for starters until I realized that I it only took 15-20 minutes to make up a couple liters of wort for a starter. After canning a few things, I quickly came to the conclusion that it was a net time loss to can wort and store it.

Just get a borosilicate glass flask and boil it on the stove and then put it in a cool water bath in the sink...and be done with it.

[Charlie]

There is one use for "canned wort", and that is to keep 5 ml in each of several screw cap culture tubes stored in the fridge. It's one of the best things to use when you're trying to capture live yeast from a brew. I suppose it could be done on a slant or plate, but often the large percentage of cells will not be viable, and I feel that the starter wort gives the best chance of recovering viable cells.

[Ozwald]

As in culturing from a bottle? I start with a hell of a lot more than 5mL on a bottle culture - it's been a while, but IIRC I was using something like 250mL for the first step... which is pretty easy to do with DME. The other advantage with DME is you can vary your starting gravity on the fly to suit your needs.

A normal pitch is going to get a 1.040-1.050 starter. While that wouldn't be nearly enough gravity stepping up a culture for a big brew, it's way too heavy for doing a bottle culture. With DME it's not that big of a deal to step it up to 1.060+ for a barleywine pitch or down to 1.010-1.015 to culture from a bottle.

You shouldn't be using tiny volumes of heavy wort when working cultures with low or questionable viability.

[brewinhard]

What about 1-2 drops of fermcap-s in the wort before autoclaving? Should alleviate any boil over issues.

[Charlie]

You shouldn't be using tiny volumes of heavy wort when working cultures with low or questionable viability.

Thanks for butting in, but I'll be my own guide when deciding on the volume necessary for my work. Using a larger volume will in no way enhance my ability to recover viable yeast.

If you leave the brew sitting in the fridge for a few days (call it 3 to 5), and then decant ala bottle conditioned brew, you will get most of the yeast captured in 25-50 ml of brew. Swirl, transfer to a centrifuge tube (or tubes), and spin at 1000 rpm in a centrifuge such as a Backman TJ-6 (sorry I don't have my rpm to g conversion table handy) and you will capture all of the yeast in a very small volume. Often the volume of packed cells is quite small, particularly if the brewery is using a DE filter, but there's always some there.

If the brew has a shitload of cells I will use sterile 2 ml Eppendorf tubes and my microfuge, but the technique is the same.

Charlie

[Charlie]

Another use for the 5 ml culture tubes of sterile starter wort (since Osvaldt asked) is to prepare a slant for culture:

1. If you have a slant that you wish to propagate into a pitchable culture you could take your innoculation loop and scoop some cells off the slant, and swirl it in your erlenmeyer containing 5 ml of sterile starter wort. But I have found that it's more efficient to dump some of the starter wort into the slant's culture tube, and vortex it for 3 to 5 minutes. This seems to suspend most of the slant's colonies. The process of suspendinig the cells may be assisted by agitation with your flamed innoculation loop if necessary.

2. Transfer the suspended yeast cells from the slant and any remaining starter wort from the culture tube into a sterile erlenmenmeyer flask with a stir bar (I use a 25 ml erlenmeyer and dinky stir bar for this stage), and put it on the stir plate for 24 hrs. Then up the volume 4X every 18 hrs or so until you get to pitchable volume (takes about 5 days for 5 or 10 gallons).

The club's resident Micro PhD recommends 4X volume boosts, but admits that a boost of 5X will probably not be detrimental to the culture's health, hence the 5 or 10 gallons in 10 days comment.

Charlie