how do you make a yeast starter?

[kgs]

@denny

@kgs

That calculation caught my eye. A ten minute boil is a long time for a small amount of liquid.  I brought a quart of water to a boil in a two-quart saucepan, uncovered the pan, and set the timer, then turned off the flame and poured out the water as soon as ten minutes were reached. The water had lost 50% of its volume.

Very interesting.  I boil for 10 min. also.  I start with 9-10 cups and end up right around 2 qt.  some loss, but nowhere near 50%.

I assume an uncovered pan, and a rolling boil, with the ten minutes starting at the beginning of the boil? I was surprised by my boil-off results myself, but there it was. I’ll test it again for repeatability. As tests go, it’s an easy one This time, I’ll wear a lab coat.

I wonder if wort boils off more slowly than water. I wonder if I’m over-thinking this and should RDWHAHB (actually I am!).

[tygo]

I generally boil my starters in an Erlenmeyer flask which helps keep the boil off down.

I don’t usually wear a lab coat though. 

[punatic]

@oscarvan

Give him some chin whiskers and he looks a lot like Tom…

[bluesman]

@punatic

Is boiling the starter wort for sterilization or hot break, or neither/both/something else?

I used 10% cause it’s easy and in the ballpark.

Sterilization.

Boiling starter wort is necessary to produce a sterile environment for the yeast to grow in.

Hot break will come with the boil but I don’t believe it’s necessary.

[denny]

@kgs

I assume an uncovered pan, and a rolling boil, with the ten minutes starting at the beginning of the boil? I was surprised by my boil-off results myself, but there it was. I’ll test it again for repeatability. As tests go, it’s an easy one This time, I’ll wear a lab coat.

Ooohh, impressive!  A lab coat will definitely guarantee results!  ;)  I do my boil as you describe.  I use a 6 qt. SS post to boil a bit over 2 qt.  I wonder if the geometry has something to do with it?

@kgs

I wonder if wort boils off more slowly than water.

I wouldn’t think so.

[tschmidlin]

@punatic

Give him some chin whiskers and he looks a lot like Tom…

You’ve got to lose the tie too ;D

[beersk]

hmmm I usually do 1/2 cup DME to 1 quart of water.  I think sometimes I use just a little more water to account for boil off.  I don’t typically worry about the gravity too much, as I believe 1/2 cup DME per quart of water gets me in the ball park with a 10 minute boil.  Cool the wort, shake, add yeast, shake some more.  I also intermittently shake my starter throughout fermentation also to keep the yeast suspended more. 
Seems to work fine for me.