Decanting stepped starters

[Crusty]

I've been looking a lot more closely lately about yeast viability & volumes & wondering how many of you guys decant the fermented wort from your first stepped starter before going into stage two of the step.
If I'm needing a 3.5lt starter, I will pour the yeast into a 1lt starter, stir for 24hrs then pitch the whole thing into the waiting 2.5lt starter. After another 24hrs, cold crash, remove on brew day, allow to come to room temp, decant, swirl & pitch.
How many of you guys cold crash after the first 24hrs, warm to room temp, decant the spent wort then add the waiting starter volume to the decanted yeast flask?

 

[DJ_L3ThAL]

I typically build starters from harvested (from a previous starter), so because the yeast may be of low viability I decant between each step (after cold crashing in fridge). Simply to remove the alcohol which allows the yeast to be in as healthy an environment as I can provide them.

PS. I always decant as soon as I remove from the fridge, as letting the cold crashed starter warm up stirs in some of the settled yeast back into suspension, so by decanting most of the beer off the top and leaving just enough to swirl the yeast into a pitchable slurry I avoid wasting some yeast if decanting later.

 

[Rocker1986]

I've been wondering the same thing. I've never done a stepped starter but I will need to on my next pilsner batch. I was thinking of decanting the first litre before pitching into the bigger 4 litre size but yeah still undecided on it really.

 

[coopsomulous]

When stepping up, I do not decant or cold crash. My process is as follows

1st Step - 1L starter @ 1.037 - 100g DME in 1 L.
2nd Step - 2.5L starter required - 250g DME in 1.5L water. Add the full first step to get 2.5L in total volume.

Makes things simple.

 

[DJ_L3ThAL]

Also depends on how you calculate your steps, but I'm pretty sure yeastcalc website calcs it so that if it said you needed a 1L then a 3.5L to grow the right amount of yeast cells you need to either decant after the first step, OR pitch the 1L stater into 3.5L. As by pitching into only 2.5L you won't get the same amount of growth since the yeast chewed the sugars from the first 1L step.

 

[DJ_L3ThAL]

When stepping up, I do not decant or cold crash. My process is as follows

1st Step - 1L starter @ 1.037 - 100g DME in 1 L.
2nd Step - 2.5L starter required - 250g DME in 1.5L water. Add the full first step to get 2.5L in total volume.

Makes things simple.

Sure that is "simple", but understanding how many cells you are starting with approximately, how many you require and adjusting your steps to achieve that number of cells is going to make you better beer than making a starter by 1L then 2.5L blindly. Depends what results you are trying to achieve and the level of effort you want to put in.

 

[coopsomulous]

I should also add that I also overbuild my starters by 100 billions cells. I use the homebrew dad yeast calculator so I have all my counts. Nothing is done blindly, the above example was just an example. All my steps are done so I have the required pitching rate and overbuild amount..

Cell growth is partially determined by sugar concentration, so if you don't decant and add to 2.5L fresh wort for 3.5L total volume, your cell growth will be less as the concentration is lower.


*Edited for clarification*

 

[coopsomulous]

The overbuild is split off before pitching for return to my yeast farm

 

[Black n Tan]

I think it is best to decant after each step. Typically I let my starter go for 2 days to build up glycogen reserves before cold crashing. So for step starter I like to start at least 1 week before brew day to allow for this process. Takes a bit longer but little more labour, and I think you get a good healthy pitch of yeast.

 

[Crusty]

I typically build starters from harvested (from a previous starter), so because the yeast may be of low viability I decant between each step (after cold crashing in fridge). Simply to remove the alcohol which allows the yeast to be in as healthy an environment as I can provide them.

PS. I always decant as soon as I remove from the fridge, as letting the cold crashed starter warm up stirs in some of the settled yeast back into suspension, so by decanting most of the beer off the top and leaving just enough to swirl the yeast into a pitchable slurry I avoid wasting some yeast if decanting later.

I'm doing things a bit differently with the White Labs. I'm trying to build up a few vials, 5 actually from the 1, so according to WL, I have a vial of 100 billion cells & I want 5 vials x100 billion cells. YeastCalc calls for a total starter volume of 3.5lt giving me 527 billion cells at the end. Sticking to the pitch rate advised by YeastCalc ( 25-100mill cells/lt ) I make a starter of 3.5lt, ( 1.040 ) transfer 1lt to another flask & boil both. When cool, pitch the 1 vial & stir for 24hrs. I usually then just dump the whole thing into the waiting 2.5lt flask & spin again for a further 24hrs. Cold crash, let come to room temp on brew day, decant, swirl & pitch. I might decant straight after cold crash from now on leaving just enough wort to rouse the yeast & then let come to room temp. I think cold crashing after each step might be good practice too. When I decant the wort from the yeast, I'll pour that into a sanitised jar taking note of the yeast volume & then top up the jar with cooled boiled water to the ? ml mark on the jar. This will give me the 5 vial volume with equal amounts of yeast in each one. Then it's simply making another starter for the actual brew.

When stepping up, I do not decant or cold crash. My process is as follows

1st Step - 1L starter @ 1.037 - 100g DME in 1 L.
2nd Step - 2.5L starter required - 250g DME in 1.5L water. Add the full first step to get 2.5L in total volume.

Makes things simple.

I never decanted between steps in the past but I'm starting to believe that it might be beneficial for yeast health if you do.

 

[Crusty]

The only problem I can see with decanting is the reduced cell count per volume of wort.
In this example, my first step will yield 187 billion cells in the initial 1lt of wort.



Now, if I decant the wort & have the 187 billion cells to pitch into my waiting 2.5lt starter wort, the inoculation rate is borderline & my finished yeast cell count is now lower, 446 billion cells. If I just tip the initial 1lt into the waiting 2.5lt, my initial 3.5lt starter should yield 567 billion cells. I don't think I'll bother decanting actually between steps.

 

[Black n Tan]

Now, if I decant the wort & have the 187 billion cells to pitch into my waiting 2.5lt starter wort, the inoculation rate is borderline & my finished yeast cell count is now lower, 446 billion cells. If I just tip the initial 1lt into the waiting 2.5lt, my initial 3.5lt starter should yield 567 billion cells. I don't think I'll bother decanting actually between steps.

There is a mistake in your calculation. In the second screen shot the viable cell count is actually 65B not 187B as you intended, because based on the production date the assumed viability is only 35%. Change the production date to today i.e.. 100% viability, and see what happens.

 

[seamad]

If you split your WL vial into 5, then your initial cell count is 20 billion cells, not 100 billion

 

[Crusty]

There is a mistake in your calculation. In the second screen shot the viable cell count is actually 65B not 187B as you intended, because based on the production date the assumed viability is only 35%. Change the production date to today i.e.. 100% viability, and see what happens.

It is too, I overlooked the production date.
Ok, back to decanting now I think.
Cheers BnT

 

[Rocker1986]

If you split your WL vial into 5, then your initial cell count is 20 billion cells, not 100 billion

No, it's not. The idea is to pitch the whole vial into a starter and then split the resultant yeast between 5 vials.

 

[Crusty]

If you split your WL vial into 5, then your initial cell count is 20 billion cells, not 100 billion

I'm not splitting it into 5.
I'm adding the whole vial, 100B cells to a starter to end up with over 500 billion cells, 5 vials.
After rinsing the final step, I'll pour it all into a sanitised jar, take note on the yeast volume then add the required amount of cooled boiled water to fill my 5 vials @40mls per vial.
I should get 100B cells in each vial.

Edit: Beaten by Rocker

The main reason for doing this is not just financial but to grow some fresh yeast from some vials that are close to best before date & to have a bank of yeast on hand ready to use. I plan on using all but the last vial & repeat the process again. I'll probably do this consecutively up to 5 times so it will be some time before needing to re-buy the yeast.

 

[seamad]

yep, sorry 'bout that, misread it. I split wyeast's into 4 and build up that way, hadn't thought of doing it the other way.

 

[Crusty]

yep, sorry 'bout that, misread it. I split wyeast's into 4 and build up that way, hadn't thought of doing it the other way.

I do exactly what you do with Wyeast. I fill 4 vials which gives me 25B cells in each & go from there.
The problem arises with the liquid volume differences between Wyeast & White Labs. Wyeast has 100B cells in 125mls of solution so it's easy to split the pack.
White Labs however has the same amount of yeast but bugger all liquid in the vial so that's where the vial volumes need to be taken into account as I want to fill 5 vials.

 

[danestead]

My process is as follows, and isn't necessarily the best way to do it however it is my interpretation on what I think the guys in the know (John Palmer type people) suggest.

Example.

1. 1L starter (100g DME into 1L total solution for 1.037).
2. 0.1g/L wyeast yeast nutrient.
3. On the stir plate at room temp (ideally within 18-24 degrees).
4. Once bubbles finish, turn stir bar off and allow the yeast to build their glycogen reserves for 8-12hrs.
5. By this stage, I sometimes put it in the fridge to let the yeast floc into a more compact layer, sometimes I don't.
6. Prepare 2nd stage of starter, lets say 3L (300g DME into 3L total solution for 1.037). It is usually in my next size bigger flask.
7. Decant the beer off the top of the yeast on the first stage.
8. Pour into 2nd stage.
9. Repeat from step 3 onwards.

When stepping up, I do not decant or cold crash. My process is as follows

1st Step - 1L starter @ 1.037 - 100g DME in 1 L.
2nd Step - 2.5L starter required - 250g DME in 1.5L water. Add the full first step to get 2.5L in total volume.

Makes things simple.

I've seen twice in the last couple of days, guys adding extra DME for their 2nd stage of the starter like you have. You have added 250g of DME into 1.5L rather than the 'usual' 100g/L. I know you will end up with different yeast counts if you did it as a single stage starter of 2.5L but wouldn't adding 350g into 2.5L of wort give the effect of a starter gravity of 1.051 rather than the 'usual' 1.037-1.040ish?

What is your basis on including that original 1 L of starter volume in your DME calculation on the 2nd stage?

 

[danestead]

When stepping up, I do not decant or cold crash. My process is as follows

1st Step - 1L starter @ 1.037 - 100g DME in 1 L.
2nd Step - 2.5L starter required - 250g DME in 1.5L water. Add the full first step to get 2.5L in total volume.

Makes things simple.

Any thoughts on the above ^^^^^^^ Tommy?