Yeast Starting Questions

[drsmurto]

Have done a bit of searching, read a lot of good info about making yeast starters, collecting/washing trub, storing yeast etc.

Havent done much of this, been sticking (almost religiously) to US56 and S-04 since i only make ales.

So i want to get some sort of feel for what the do's and dont's with yeast starters are.

I have a conical flask that i fitted with an airlock for making a starter, stepping up from 250mL to 2L.

I noticed some people have built themselves stirrers and have read about this speeding up the process.

Questions
1. stir or no stir
2. airlock or no airlock. Are they necessary or can i just fit the flask/bottle with gladwrap and a rubber band?

I am in the process of building up some 1007 for an alt this weekend and so far have 250mL going along nicely. I plan on adding it to a 2L malt solution this evening with the aim of being able to pitch it sunday or monday.

3. Do i need to wait until the krausen dies down (see pic below) before adding it to the 2L of malt extract (200g of LDME in 2L)?

Sorry, a lot of questions in 1 post.....

EDIT - i should have added that i started off with 1/10th of a smack pack - a spilt from a Stamm a few months ago

Cheers
DrSmurto

 

[braufrau]

1. stir or no stir

Definitely. But you can just give it a good shake now and then.

2. airlock or no airlock. Are they necessary or can i just fit the flask/bottle with gladwrap and a rubber band?

Not necessary. Gladwrap or just the the lid of the bottle slightly ajar. Or screw the lid on properly
and let out the gas every 12 hours or so .. which is fun.

 

[sstacey]

I just put aluminium foil over the opening on my flask. I swirl it by hand every time I walk past.

 

[mfdes]

Stir vents CO2 and introduces O2. Result: more yeast.

As for lid, can't get past alfoil. I autoclave mine with alfoil, but you could pot it onto a gas flame or electric element (with diffuser) to boil gently for a few minutes and let the steam sanitise the inside of the container.

MFS.

 

[braufrau]

As for lid, can't get past alfoil. I autoclave mine with alfoil,

I pressure cook (autoclave) small things like that, including the jars I store the yeast in long term in fthe fridge.
cant' fit my 2l jar in the pressure cooker dang nang it!

 

[matti]

Dr smurto you nice stuff.
I am trying to convince work to give the spare stirrer.
Are you Stepping up from 250ml->500ml>1L->2L
or straight to 2 litre.

Either way Give it more oxygen for yeast growth.
shaken or stirred?

 

[mfdes]

Dr smurto you nice stuff.
I am trying to convince work to give the spare stirrer.
Are you Stepping up from 250ml->500ml>1L->2L
or straight to 2 litre.

Either way Give it more oxygen for yeast growth.
shaken or stirred?

10x volume steps are generally recommended. i.e. 50mL to 500mL to 5L

MFS.

 

[Sammus]

I've read from several reputable sources that 5 to 10 fold steps are recommended.

Just a question, to sterilise an empty lidded (obviously not sealed at this point) jar/flask in an autoclave (ie one that doesnt have agar in it) do you have to put a bit of water inside to get the wet heat onto the inside surfaces? how much would you use?

 

[Sammus]

1. stir or no stir

According to the Wyeast pitch rate calculator and mrmaltys calculator (forget the actual urls, but one is on the wyeast website, the other is on www.mrmalty.com) the stir plate makes a pretty significant difference in end cell count when making starters. Basically means smaller starters, im also pretty sure it ferments out quicker too, so less time.

and re: the question about when to pitch, I prefer to wait till its fermented out, so I get the cell count right up, then I chill to floc the yeast and decant the starter wort (probably lose a bit of yeast in the suspension there), its normally just dme in water, different to the beer im brewing. I think if you pitch at high krauen though you will have zero lag time, which also has its merits. I only just built my stirplate (second one, I lost my first one that I never used when I moved... :huh: ) and havent played much yet. Still experimenting and same as you - lots of reading

 

[drsmurto]

Lots of good advice - i use one-shot to sanitise the flasks prior to the starter and plan on using ethanol to sanitise jars/vials for yeast storage.

Stepping up from 250mL to 2L so am in between the 5 and 10 x

 

[Keifer]

I bought a 2L erlenmeyer flask from grain n grape, yet to use it as i've gone back to kits for a little bit, but my question is can i boil the starter with a direct flame? we have a gas stovetop. Or would i need to diffuse the heat as mentioned before?

 

[Sammus]

I boil stuff in my erlenmeyer flasks directly all the time, on element stoves or on gas. Even an el cheapo flask I got from www.wiltronics.com.au

PS instead of buying flasks from G&G I would recommend the above website or www.livingstone.com.au - they cost a fraction of G&G charge for them, even for brand name ones (theres no schott duran, but they do have simex)

 

[matti]

10x volume steps are generally recommended. i.e. 50mL to 500mL to 5L

MFS.

Cheers.

 

[jamilz]

I posted an article on my website covering some of the most common yeast starter questions. It might be helpful:

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

 

[mfdes]

No need to put water into the containers.
Steam will get in there. The trick is to have 121 degree moist air / steam in there. Closed stoppered bottles sterilise fine, you don't have to crack the lid open a bit as is often said.

MFS.

 

[Sammus]

No need to put water into the containers.
Steam will get in there. The trick is to have 121 degree moist air / steam in there. Closed stoppered bottles sterilise fine, you don't have to crack the lid open a bit as is often said.

MFS.

I figured if it is closed then there would only be dry heat inside the vessel. According to this website, wet heat is much more effective, only requiring 20min at 121C, compared to dry heat requiring nearly an hour at 170C to sterilise.

 

[dr K]

Just be carefull direct heating even quality Borosilicate, I used to (halogen hotplates seems safe) until a weekend or so ago we were talking and some one mentioned exploding a flask on direct heat, where are asbestos mats when you need them!!
A few days later I was happily heating some freshly extracted soy milk ( I make soy milk from the beans and Tofu from the soy milk) in my 5 litre Schott Duran beaker when I heard a crack and a spit..I turned off the heat, ran and got a lot of towels.... let it cool a bit then carefully ladled the milkout into a stainless pot, picked it up and poured the last in...put it aside..an cooling I examined it and it had cracked all the way around the base.
Now thats luck !!

K

 

[Hargie]

.....Kurtzie, i reckon that you ladle-ing anything other than
'Brett not Bruce' carefully would be rarer than chickens lips....

....love,
Cougar....

 

[dr K]

Cougar

It was only the smell of your 30 year old Aramis aftershave drifting south that saved my sweet little arse.

K Boy

 

[Hargie]

....hahaha....i don't even know what that means.....