quick stir-plate and starter questions

[droid]

hi all

very happy to have a new heated digital stir-plate here and some 2206 yeast (albeit mid nov manufacturing date) and some flasks ~ 500ml, 1000ml and 2000ml

i am doing a double batch lager and am using a 1.5x ratio starter as per brewers friend for Lager

the plan is:
500ml today - Saturday (all at 1.040 and 25deg C)
1000ml - Sunday
2000ml Tuesday
4000ml Thursday

brew next Saturday

does this sound right?
do i have the starter stirring constantly or do i shut it off every-now and then? essentially it's going to be running for a week?

soz for the questions answered a million times no doubt

 

[Reman]

Looks like it should be ok, plugging some numbers in I get 750b cells required for 40l of 1.050.

After the 2l starter using C White Stirplate calc gives 479b which means last step should get you there.

Mid-November vial is at 20% vitality, so obviously a newer vial would get you there quicker

* using http://www.captainbrew.com/yeast-pitch-rate-and-starter-calculator

 

[Black n Tan]

I don't think this is the way to go. Firstly I have read that pitching a Wyeast pack into less than 1L of starter will leave the yeast in poorer health than they started. Secondly, doubling the starter will result in very little growth and will probably result in poor vitality. Ideally steps should be 5-fold, but practicalities need to be considered and I usually find a 1L then 4-5L starter works well for 40-50L of lager at moderate gravity. I let the starter go for 2 days then cold crash overnight, ditch the spent wort and repeat the process. I like to use this calculator and use Kai Trotter's stipulate option http://www.captainbrew.com/yeast-pitch-rate-and-starter-calculator. Kai has done some experiments and has found that yeast growth is pretty proportional to the size of the starter when using a stirplate, so doubling the size of the starter will result in double the yeast. He is a little critical of Jamil's calculator especially as the supporting data is not provided. Check out Braukasier if you want more info. http://braukaiser.com/blog/blog/2012/10/08/yeast-growth-experiments-some-early-results/

 

[Reman]

BnT, my problem is that there is a massive variation between the Troester formula and the White formula. Both have top credentials in yeast. I used the White as I'd prefer to over estimate than under

 

[Black n Tan]

I think Chris White's studies were performed on non-stirred starters and then extrapolated for a stirplate which obviously relies on a bunch of assumptions. Happy to be corrected but that is my understanding. My preference is to use a calculator that uses the actual results from yeast growth studies using a stipulate at home-brew scale and because the methodology and results of those studies are made available for you to scrutinise. Chris White's calculator would suggest that I am under pitching by 40% and I just don't believe it: gold at the Nats for a pale lager would suggest I am not under-pitching. Perfectly understand if you want to use Chris Whites calculator but there may be unintended consequences (for some) other than a modest over-pitch. One thing all these calculators fail to address is the vitality of the yeast: yes we want to increase yeast numbers but they must be healthy vital yeast. If I followed Chris White's calculator i would need to make a three step starter and then start compromising on the size of each step up (which is exactly what the OP is proposing) and the result may be more yeast but with lesser vitality. In addition each additional step increases the risk of contamination. So for me I use a yeast calculator based on Kai's studies.

 

[Mardoo]

FWIW I've been using the White statistics on the Captainbrew/yeastcalc calculator for 18 months now. I see so few esters in yeasts that should be throwing them right and left that I'm switching back to the Braukaiser figures to see whether that makes any difference. I also regularly get crazy fast ferments on the order of three days.

I strongly suspect that the White statistics are producing overly large pitches that are not favourable to flavour development. Nothing definitive here of course, but this is a regular pattern I'm seeing which differs from my prior experience.

 

[Black n Tan]

Mardoo to be honest I suffer the same thing even using Kai's figures. I had an ESB and Best Yorkshire Bitter finish in two days and cold crashed at day 4 because it had cleaned up already. Grain to brain in 7 days and both are cracking beers but low on esters. Do you use oxygen? Ester formation is complex with a lot of contradictory advice.

 

[droid]

thanks for the replies but damn, now what?

its been on a 500ml (actually 500ml + the pack) so 600ml+ since Saturday 6pm, i thought i read on here to double each step...so i bought 3 flasks ~ 500, 1000 and 2000ml plus i have 5ltr glass demijohns to get to 4ltrs, not sure if the shape of the base of the demijohns will be ok - they're slightly concave from memory, might be up for a 5ltr flask

my personal thoughts are, if this yeast is at 20% vitality and then going by the pack instructions i could pitch onto 1/5th of the wort they recommend ~ up to 1.060. that says i should have no problems going to straight to 5ltrs?
then i look at the brewers friend calculator and it suggests 1.5x because it's a lager. i also thought there was a temp correction thing as it will be pitched onto 6 degree wort and warmed to 8 for the main ferment

maybe i should just go from 1 to 5 or in this current case maybe 600ml to 2000 to 5000

buggered if i know

 

[droid]

thx for the linx :beer:
* 1.040 starter grav and 1.5x (Lager pitch) with 15/11/2015 manu date = 19.3% vitality and a target OG of 1050:

right well the k.troester one gets me there in two steps (1ltr to 5ltr) and if i did three going 1 to 2 to 5ltrs id be way over like 1200bill where i require just under 800bill
if i use the c.white the 1 to 2 to 5 ltrs gets there just over what i need

i have two lager yeasts to spin up, both with the same date code (both Nov 15 anyway), one is the 2206 and the other is the 2278 for a pils the week after the marzen

the marzen yeast is going into the fridge at 6 degrees and warming to 8. given the ferment temp i think i will go with what i have on the stir-plate now (600ml) and go to 2 then to 5
the pils - shit i dunno, maybe the same because of the 20% vitality, maybe i could do 1ltr and then go to 5ltr but i worry about not pitching enough with the style, the vitality and ferment temps

 

[butisitart]

slight digression here but i think a valid one, as i also acquired a stirrer last week....

i note that in a 5L flask, the supplied (1 inch) stir bar works fine at around 1L wort, but it appears to be too small to get centred in 4L wort.
i assume it's time to get much bigger stir bar????
if so, found lots of cheap choices here (along with a load of other useful stuff)

https://www.proscitech.com.au/?navaction=show_page&chapter=l&page=5

(got the home page from other threads.)

is the size of my weeny bar most likely the problem?

 

[Mardoo]

butisitart, I have two of the 40mm egg-shaped ones from the page your listed, L37-4020. They rock. Totally silent and can move large volumes of liquid with no issue.

B&T, thanks for that. Saves me some time! Yes I have been using oxygen. I have been planning to cut that out as part of my experimentation, so now I'll try both sets of statistics without added oxygen and see if that makes a difference. No guarantee it will

 

[butisitart]

thanks mardoo...
i were trying to guess a good size, i assume you only use one at a time?? :huh: (serious question)
also - there's one there that looks like a wheel with fins... don't suppose you've tried that one. looks like fun - maybe later when i replenish the piggy bank

 

[Reman]

I'll defer to BnT on this one, doing some research it looks like White method has a pretty fundamental flaw which didn't take into account stirring the starter.

Very good referenced blog post http://www.woodlandbrew.com/2015/02/yeast-starters-stirred-vs-not.html

Key take away, you will end up with the same amount of yeast, a stir plate will just take less time.

Also this thread has some great links http://aussiehomebrewer.com/topic/74794-nhc-2013-kai-troester-braukaisercom-on-stirplate-starters/

 

[Black n Tan]

B&T, thanks for that. Saves me some time! Yes I have been using oxygen. I have been planning to cut that out as part of my experimentation, so now I'll try both sets of statistics without added oxygen and see if that makes a difference. No guarantee it will

Mardoo, I am still trying to understand this myself and don't have the answers. Although I have suspected oxygen as being detrimental to ester formation, I recently made a batch of hefeweizen and wanted to tease out more banana, so I under pitched and didn't use oxygen. Anyway it didn't turn out great and there was no extra banana. Next time I will just increase fermentation temp. As I said ester formation is complex with contradictory advice about the effect of yeast growth on ester formation. Considering you have changed both pitching rate and oxygenation, I would start looking there, but would look at reducing oxygenation of the wort but wouldn't eliminate it.

 

[Mardoo]

Butititart (which my spellcheck thinks should be burrito tart ) - one bar at a time. Otherwise one of them will get thrown by the centrifugal force. I too would love to try one of those wheels!

Thanks B&T. I wouldn't eliminate oxygenation, but I'm thinking of returning to "air" only as opposed to pure oxygen. I've kept my oxygenation rates towards the low end, so I don't think over-oxygenation is a factor. Thanks for your help!

 

[TheWiggman]

I'd be following post #3, 1l starter > 5l and add yeast nutrient and oxygenate both steps if you have the gear. You really want fresher yeast than that but if that's all you have then not much else you can do apart from buy fresher yeast. I think you'll be on the borderline for the right yeast count on your first lager but see how you go. If you increase cell count you'll be sacrificing yeast health. I'd pitch a bit higher than 8°C because that will put further stress on the yeast and I think you'll get a better beer pitching at 11 or thereabouts.

 

[droid]

I can aerate. I could blend the two yeasts? And or ferment higher
Bit dissapointed in the old yeast but I have to mail order so I get what I get

Thanks all

 

[droid]

i think i'll ferment at 11 like the wiggman suggests - it's smack bang in the middle of the range for 2206, it does say to give it a good d-rest, no probs
no frankenyeasting this batch

cheers ya champs!

 

[spog]

slight digression here but i think a valid one, as i also acquired a stirrer last week....

i note that in a 5L flask, the supplied (1 inch) stir bar works fine at around 1L wort, but it appears to be too small to get centred in 4L wort.
i assume it's time to get much bigger stir bar????
if so, found lots of cheap choices here (along with a load of other useful stuff)

https://www.proscitech.com.au/?navaction=show_page&chapter=l&page=5

(got the home page from other threads.)

is the size of my weeny bar most likely the problem?

.

That's a good site you found, that s/s braided hose would add some bling to a brew rig.

 

[butisitart]

Butititart (which my spellcheck thinks should be burrito tart ) - one bar at a time. Otherwise one of them will get thrown by the centrifugal force. I too would love to try one of those wheels!

i haven't been a burrito tart since a certain beach party in 1981. :unsure:

i haven't ordered a spinner yet, but after your comment, maybe i will get a wheel and report back. diameter seems big enough. cheers. i'm still choosing vials and specimen jars before i go.