1st stepped up starter for 40L @ 1.060 - sanity check my method

[buckerooni]

hi all, first time doing a stepped starter using liquid yeast on a stirplate. hope you can provide some feedback.

Got 2x20L no-chill wort (similar beers) that are 1.052 and 1.060 respectively - so was gonna err on the side of caution and call it 40L at 1.060. Was going to use this wort (watered down to 1.040) for the starter. As I'm using this wort I'm changing my batch size to 37L (-3 for starter)

I've got 1 vial of WLP001, a 3L flask and stir plate

Using http://www.cheapmonkeys.com/yeastcalc/ I was going to use 1/2 vial of WLP001 (~50B cells). See attachment for what I'd planned.


So, with 2 steps the time line is:

• tonight: 1L starter on stirplate
• tomorrow arvo - stop stirplate, settle
• tomorrow night - decant, step up 2L
• next morning - pitch to both jerry's, wort+slurry (similar beers)

A few questions:
1. Process - I understand that between step ups I should stop stirplate, let it settle, decant and add fresh wort - correct?
2. Cell count - Getting to 394 instead of target 407 - is falling a little short a problem?
3. Headspace - The 2 x 20L jerry - how much headspace do I need for fermentation, do I need a blowoff? Normally I just glad wrap it.
4. Additional wort water - Any reason to boil/cool water for starter or is tap water OK?

Thanks!


edit - formatting

 

[Yob]

I dont always let settle, but I adjust my next starter.. so for example

500ml of 1030 will go into 2.5L with 300g of dme so that the total volume will = 1040 (roughly), this lets them just continue budding and not have to change process if you catch my drift

 

[buckerooni]

gotcha, thought this would be a reasonable thing to do. As I've got 1.052/1.060 wort to top up the starter with I may be able to drop it straight in (not watered down) after 24hrs as my original starter wort may have dropped a few points? Am I catching your drift and drifting along with it?

also, I figure upping the gravity of the wort close to OG values is probably not a bad thing.e.g.

1. starter at 1L @ 1.040 (watered down)
2. step up to 2L adding 1.052 wort (straight from cube)

sound reasonable?

 

[Yob]

I tend not to go above 1040 myself, cant remember why, pretty sure I read somewhere high gravity isnt great for the yeast health

 

[buckerooni]

can anyone comment on this one:

3. Headspace - The 2 x 20L jerry - how much headspace do I need for fermentation, do I need a blowoff?

Don't want to come into my shed with a balloon of krausen hanging out of my jerry's like an elephant testicle...

 

[buckerooni]

found this to help adjust the wort down to 1.040 - http://www.brewersfriend.com/dilution-and-boiloff-gravity-calculator/

 

[eMPTy]

I tend not to go above 1040 myself, cant remember why, pretty sure I read somewhere high gravity isnt great for the yeast health

I've been reading alot on starters in the last 48 hours. Everywhere seems to suggest above 1.40 (many even quote 1.30) has the potential to stress the yeast and stop it from reaching full potential.

 

[buckerooni]

thanks fellas - I will stick to 1.040.

checked the yeastman report for the vial (29/1/2015) and yeastcalc tells me it's down to 55% viability. Meh, gonna pitch the whole lot into the starter to get my cell count with only 1 extra step up.

I guess this becomes part of the routine but the little sprinkle of US-05 seems like such a simpler time!

The brewstrong podcast has a good one on yeast a little while back that I just listened to, re-enforcing the use of calcs and that underpitching is an extremely common issue with homebrewers.

 

[Yob]

You'll need to be doing more than a 1lt starter to get enough yeast to pitch to the 2 brews or I'm afraid you'll be getting some first hand experience at under pitching

 

[buckerooni]

will step it up to 2L as well Yob. prolly wasn't clear about that, apparently 2.1L gets me my 411 billion cells.

 

[fletcher]

i use the tall thin jerrys for fermenting (23L) and usually leave 2-3 litres minimum for headspace and krausen - but it really depends on yeast and ferment temp. 001 and us-05 i've usually found ferment quite 'softly' and don't go mental, but i usually ferment them low at around 15-18C. if you're using the shorter cube jerrys, i think you'll have to be mindful if they're right to the brim.

 

[buckerooni]

Got the tall jerries too and can control it at 18c no problems. Once the no-chill jerries return to their normal shape there should be 4-5 litres headspace easy.

I messed up, this is the WLP051 white labs yeast - on a quick look it doesn't look like it goes too crazy. Wait and see!

And there I was thinking my attachments of the yeastcals were being posted to this thread - fail!

 

[verysupple]

2. Cell count - Getting to 394 instead of target 407 - is falling a little short a problem?

Don't get too hung up on exact cell counts. The starter calculators available only give a quite rough estimate of what you'll end up with. There are so many factors that affect the result that an uncertainty of 20 % probably isn't out of the question. So you don't have to hit the numbers bang on. As long as the calculator says you'll be in the ball park you'll be fine.

To give you an idea of how hard it is to predict the results, here's a non-exhaustive list of factors that come in to play:
Wort gravity
Inoculation rate
Temperature
Yeast strain
Yeast viability
Yeast vitality
Yeast generation
O2 and other nutrient concentrations (not just the amounts present but the ratios of certain minerals also makes a difference)
Stir vigour (affects the result due to mechanisms other than amount of O2 being dissolved)

Most calculators take in to account inoculation rate and yeast viability only as they have quite a large impact. Good enough for our purposes but no calculation will be very accurate.

 

[buckerooni]

thanks. was amazed at the difference the stir plate adds to the growth. Happy with ballparks - it's a pretty opaque process and I didn't to go to all this effort and still underpitch (to a level that would cause perceivable problems). Should be all good in the hood.

 

[verysupple]

Yeah, I'm now fermenting my first batch pitched with a starter made on my home made stir plate. It grew a lot more yeast than when I was doing the ol' shake the juice bottle starters (I accounted for this when I determined the starter size of course). And yeah, should be all good in the hood. Pitch rates are important but rarely need to be super precise.

 

[fletcher]

Got the tall jerries too and can control it at 18c no problems. Once the no-chill jerries return to their normal shape there should be 4-5 litres headspace easy.

I messed up, this is the WLP051 white labs yeast - on a quick look it doesn't look like it goes too crazy. Wait and see!

And there I was thinking my attachments of the yeastcals were being posted to this thread - fail!

you'll be fine at those temps and that yeast with 4-5L head space. easy

 

[nosco]

http://www.mrmalty.com/starter_faq.php

This thread is a good read. The info is from white labs i think. It basically says dont use high gravity wort, keep the stir plate on through the whole process and pitch/step up when the starter is at high krausen.

As stated already high gravity wort stresses the yeast. The stir plate provides o2 but also drives off co2. High krausen is the highest point of yeast production, only 12-24 hours or something like that. I was told 24-36. Probably best to read it instead of taking my word for it

 

[buckerooni]

I'm about 36 hours in - started a 1L, stepped up to 2L last night. Been controlled at around 19c. Gave it a quick taste, still tastes like yeasty wort. Will check back tonight and see if there's been any action. If not I may have a dud vial.

 

[buckerooni]

finally hit some krausen last night but got home too late and too drunk. This morning pitched half (1L) to the 1.050 beer this morning and stepped up another 1L of wort from the 1.060 (watered down to 1.040). Of course I can't do a 1L + 2L step up in a 2L flask! yeah, though I had a 3L flask. I don't.

It's really the same anxiety of the unknown you get from your first ferments...

Observations:
- a single 2L flask is not enough. Ideally would gave 2 x 3L flasks for stepped up double batches esp. if using older liquid yeast. Love the flasks for the ability to heat the vessel straight off the stove and general ease of use (hard to spill)
- will start collecting wort in PET bottles for starters, applying a no-chill approach. This will save having to use DME and heat/cool/handle - mostly a time saving thing.
- didn't appreciate how much yeast viability drops over time with liquids until I started using the calcs

like all technical beer stuff, look forward to getting better and faster at it.