Yeast starters

[Mr B]

Read all the threads and more, appreciate a little advice. First time making starters.

Background:

I split a Wyeast smack pack into 4. Put 30ml into 200 ml wort for 24hrs, then into 1.6l this morning. Using a stirplate. Currently fizzing away madly.


Q's:

How do you know when it is time to step up? ( i just did it after 24 hours...)

How do you know when starter is finished (ready to chill and pour off wort prior to pitching)?


Further:

I have 2 25l cubes I want to start fermenting asap.

The biggest flask I have is a 2l, if I use the Brewers friend calculator (http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/), the first 200ml step builds from 19 billion to 98 billion cells, then the second 1.6l step builds to 278 billion cells, which meets the target of 254 billion cells required for a 25l batch. All good.

Then, to save time building from 30ml again - if I did another 2l step (chill the 1.6l batch, decant old wort, and put 2l of fresh wort in), the calc gives me 565 billion cells - which would be enough for both batches, and would save one step. Is this feasible/recommended? Would there be too much yeast for the wort volume (i.e. should be stepping up into a larger volume)? Maybe the chilling time would equal the step time.......... Which way would you do it?

Appreciate the collective wisdom

 

[danestead]

Its is ready to step up/finished when the little co2 bubbles have stopped rising up through your starter. If you use the torch on your phone it helps but also those bubbles tend to stick to the flask on the edge at the top. Once they have pretty much disappeared you are done.

2nd question- As per the experts (read john palmer, zamil etc) you dont really want to be adding more than 100-200 billion yeast cells per litre of wort (when you add them at the beginning, not the final yeast count) as it adversly affects the health of the yeast.

 

[kevinj]

Best youtube i have found on

 

[Ducatiboy stu]

I use the rule of the mid point between your SG of your wort and your expected FG.

I make starters at 1040 SG and when the starter gets to about 1020 I split it and make the next gen starter. or use it

 

[Cocko]

^^


Or cake pitch h34r:

 

[Ducatiboy stu]

mmmm.....cake......

 

[danestead]

I use the rule of the mid point between your SG of your wort and your expected FG.

I make starters at 1040 SG and when the starter gets to about 1020 I split it and make the next gen starter. or use it

how do you test the gravity of a yeast starter?

 

[Ducatiboy stu]

how do you test the gravity of a yeast starter?

With a glass tube that is weighted at the bottom and has a graduated scale you can read off

 

[danestead]

With a glass tube that is weighted at the bottom and has a graduated scale you can read off

So you put your weighted glass tube into your erlenmeyer flask?

 

[Ducatiboy stu]

So you put your weighted glass tube into your erlenmeyer flask?

I use coke bottles

 

[siege]

I've never bothered taking a gravity reading of a starter because they finish up so quickly. Just wait 1-2 days, look for bubbles, smells like bread, step up.
Been using the brewers friend calculator too and never had a problem until recently.

I was brewing a pale ale and a black IPA (very different SG) both using BRY 97 yeast. They both seems to get stuck and needed heaps of TLC to finish up. Kicked up the temp a bit, shook a bit, watched a bit.

I think I need to look a bit further into the pitching rate options on that calculator. Just something to think about because you can do all your steps right and still be up the creek if the pitching rate was wrong to start with. 2c.

 

[Ducatiboy stu]

The trick is to pitch at high krausen when the yeast is most active

 

[verysupple]

The trick is to pitch at high krausen when the yeast is most active

I like doing that when it's sensible to do so - i.e. when the starter volume is small enough that it won't change the flavour of the beer. But I prefer to let it finish out, chill, then decant off the spent beer first if it's a big starter for high gravity ales or lagers.

I have used both methods on average-ish gravity beers with the same oxygenation regime and pitching the starter at high krausen gives a shorter lag time, but I haven't noticed it actually making a better beer than pitching just the chilled slurry.

 

[Ducatiboy stu]

Works for me. I also draw starters from my fermenter at high krausen as well

 

[stux]

http://yeastcalculator.com

Now allows you to use Kai's growth curves which are much better for stirred starter stepping (growth approx = to 1.8B cells per gram of DME on a stirred starter)

 

[ianh]

http://yeastcalculator.com

Now allows you to use Kai's growth curves which are much better for stirred starter stepping (growth approx = to 1.8B cells per gram of DME on a stirred starter)

That's the one I use, also now gives a % viability for year old yeast rather zero. Still working through my stocks of March 2014 1469PC.

As I now make mainly Pale Ales/ ESBs. I take 1.5 litres of wort from the current brew. Make a starter with 1/5th of a pack in 500ml for 24 hrs then add 1000ml for 48hrs on a stirplate. Store at 1C then decant to 400-500ml for use in my next brew and 1469PC still wants to jump out of the fermenter.

 

[stux]

Fired up a quarter split of 1469 from 10/10/11 the other day!

Was fine except vinegar flies got into the starter

 

[Adr_0]

Don't forget to make sure you keep the temp difference between your wort and yeast/starter to <10°C. I have no doubt this stunts the growth a bit, and probably produces some stress flavours from the yeast. Looking back at ferments that have taken a while (>24hrs) vs those that have started strongly (<8hrs) this 'shock' temperature (or lack thereof) has played a big part.

If you get the temperatures matched nicely, your hard work in doing the starter pays off.

 

[Mr B]

Gents thanks for the info, great to have clarification on the points above.

I woke up early and prepped another starter to start, and fridged the finished one.

Exciting new world

Cheers

 

[Mr B]

First batch is cranking, much faster start than all my previous ones using rehydrated dry yeast. Love it.

How long does it take for the yeast to drop out in order to pour off the wort and pitch?

I fridged the second 2l starter around 3-4 hours ago, and there is a nice distinct patch on the bottom. I assume some is still in suspension, but anyone know for practical reasons how long you should wait?

Can either pitch later tonight or in the morning, but as the question arose it would be good to know

Slight preference to doing it tonight rather than before work tomoz

Cheers