Question about boil times for starter wort

[sudsmcgee]

I've read various tutorials on making starters that suggest you should boil the wort for anywhere from 10-20 minutes. My understanding is that once pathogens reach 212 degrees F they are dead.

Is there another purpose for the 10-20 minute boil of the starter wort, or is it just a waste of gas and time? I could see getting past the hot break, but beyond that, I'm not seeing the point for a longer boil.

 

[Revvy]

I don't boil for more than a couple minutes.

 

[sudsmcgee]

Thanks Revvy. I just made my first starter (I have used only dry yeast until now) and boiled it for about 2 minutes. I just wanted to make sure I wasn't missing something.

 

[Revvy]

I always thought that admonition was odd. If you boil 2 cups of something for 20 minutes, you're going to probably have less than one cup of it left. I think folks got that mixed up with the ide of holding something at pasturization temps for 15-20 minutes.

 

[theonetrueruss]

depending on the source I see anything from 3 minutes to 20 minutes. It should take some amount of time to be sure that the heat is evenly dispersed through the vessel and the things we're killing will need some time to die.

So- for the volume in a starter, and the fact that we are talking about mostly clean water to begin with, there isn't a lot to kill in it, and what is there is tiny and with the sugar will have plenty of heat transfer going on.

I think 5 minutes of boiling is plenty for a starter. I think the time in pasteurization is to make sure the whole thing actually gets to the right temperature.

 

[sudsmcgee]

The thing is, the nasties die at 160 degrees, so the time it takes for the water to reach boiling is already enough to kill everything that might exist in tap water.

 

[Revvy]

The thing is, the nasties die at 160 degrees, so the time it takes for the water to reach boiling is already enough to kill everything that might exist in tap water.

Good point!