Old(ish) yeast starter

[dougEdoug]

I made a yeast starter 1 week ago with wyeast budvar 2000 in 1L Light DME wort at 1.040. It has been sitting in my room at around 68 F for the past week and the fermentation pretty much stopped after about 3 days as usual. I was expecting to brew last weekend but didn't have the time so it got postponed until this weekend. My question is whether the starter is still good or should I decant off some of the wort and refill with fresh wort solution to kick it back into active fermentation. The starter is in a 1 L erlenmeyer flask so just topping off with fresh wort isn't really an option. I will be pitching into a dark bohemian lager with OG around 1.057 (strong 14 degree dark lager). Thanks!
-Doug

 

[Dos_Locos_Brewery]

If you have the time, re-pitching wouldn't hurt. If that doesn't fit in, the yeast you have should be fine. You can hedge your bets by oxygenating the Bohemian well. The 1.057 shouldn't be too much of an issue.

 

[johnnyc]

Looking at Mr Malty a 1L starter for a 1.057 lager is underpitching in the first place. The calculator calls for 4 vials or a 2.25L starter (with occasional shaking). I would chill the starter, pour off the spent wort and add another L of 1.040 wort to get you close to the optimal pitching rate.

 

[Revvy]

Yeah, I agree with Johhnyc, decant and build up the yeast you have.

 

[dougEdoug]

Alright, that sounds good, I'll decant off most of the starter and put in some more wort to bring up the pitch rate. On a related note, I brewed an AG budvar clone (with wyeast 2000) 10 days ago, I heard that kraeusening is a more common process than diacetyl rest for bohemian pilsners so I think I will give it a shot. I didn't save any extra of my AG wort for kraeusening, could I kraeusen with the old wort I will decant off this starter, or maybe boil up a small wort with some extra light dme and a few (calculated and weighed) saaz pellets and pitch some yeast into it to kraeusen with that?
Thanks for the help!

 

[johnnyc]

Hey Revvy along those same lines, I'm looking at a RIS calling for a 6L starter, I'm thinking 2L on stirplate, decant and add 2 more, decant and add 2 more. I've only got a 2L flask. OG 1.100 Thoughts?

 

[Revvy]

Hey Revvy along those same lines, I'm looking at a RIS calling for a 6L starter, I'm thinking 2L on stirplate, decant and add 2 more, decant and add 2 more. I've only got a 2L flask. OG 1.100 Thoughts?

You don't need to use a "flask" do you have any other containers? THey don't have to be glass, they don't have to be "scientific," they just need to be a container. Any glass or strong plastic container will work that you can sanitize...I've seen all sorts.

These are some from the web....

I've used a large spaghetti sauce jar before...It worked great on my stirplate when I didn't want to use my large flask for a small amount of harvesting yeast.

Basically anything will work for you as long as it is sanitized.

One thing, using an airclock on a starter is no longer recommended practice....just a piece of sanitized foil on top is all you need, since you actually WANT oxygen in there, and an airlock is meant to keep air out of it...

You could also just keep decanting the liquid off...Or you could grow three containers at the same time.

 

[johnnyc]

My flask is the only thing I've got that will work on my stirplate, my 1 gallon jugs have domed bottoms, my juice pitcher has a bottom thats too thick, etc, etc. I've scoured the house looking for something that'll hold more but haven't found anything yet. I actually used a stainless steel pitcher from the kitchen for a while but that doesn't hold any more than my flask.

 

[Revvy]

My flask is the only thing I've got that will work on my stirplate, my 1 gallon jugs have domed bottoms, my juice pitcher has a bottom thats too thick, etc, etc. I've scoured the house looking for something that'll hold more but haven't found anything yet. I actually used a stainless steel pitcher from the kitchen for a while but that doesn't hold any more than my flask.

Ya do know that millions of brewers make successful starters all the time who aren't blessed like you and me with stirplates, dontcha.

I really can't think of a way to do it all at once with a stirplate.

Hmmm...You COULD just brew your starter in your fermenter...then rack off the beer and then rack your RIS on top of that cake....I have heard of a lot of brewers doing that, just making a small beer and racking onto that yeast.

Heck do a 2.5 gallon test beer and then more than likely you will have too much yeast on RIS day.

 

[craven_morhead]

Any suggestions for getting more oxygen to a starter that's not on a stirplate? I've had a couple of batches of yeast harvested from a while back, and they don't seem to take off like they should. I'm not sure if they've died off, aren't getting enough food, or not getting enough O2.

 

[johnnyc]

Hmmm, not a bad idea. I was planning Edwort's Porter for Saturday anyway. Might not be bad with WLP004 Irish Ale.

 

[Revvy]

Any suggestions for getting more oxygen to a starter that's not on a stirplate? I've had a couple of batches of yeast harvested from a while back, and they don't seem to take off like they should. I'm not sure if they've died off, aren't getting enough food, or not getting enough O2.

Same thing many of us use in our fermenters.

http://www.williamsbrewing.com/WILLIAM_S_OXYGEN_AERATION_SYST_P699.cfm

 

[Revvy]

Hmmm, not a bad idea. I was planning Edwort's Porter for Saturday anyway. Might not be bad with WLP004 Irish Ale.

The more I think about it the better I like the idea...you end up with two beers for the price of one.

 

[remilard]

Hey Revvy along those same lines, I'm looking at a RIS calling for a 6L starter, I'm thinking 2L on stirplate, decant and add 2 more, decant and add 2 more. I've only got a 2L flask. OG 1.100 Thoughts?

Three steps, 2+2+2 is not equivalent to a single 6 l step.

Wyeast has a pitching calculator that explicitly allows you to do three steps, not as many options as Mr. Malty though (and you have to know how many cells you want to pitch, it doesn't tell you).

Here is how to use the Mr. Malty calculator to do a stepped starter. This example will be a two step, but you can do it for as many iterations as you need.

1. Start with your last step. I just put in a yeast manufacture date of Nov 1, stir plate, 6 gallon, 1.100 SG. 1 yeast pack requires a 4.5 liter starter, and I can't do that on my stir plate. I will figure out how many yeast packs I need so I can make a starter in my 2 liter flask. Turns out 2 yeast packs requires a 1.82 liter starter, perfect. Now I could go buy 2 yeast packs, but I don't want to sooooooo:

2. Now I need to figure out how to grow one pack of yeast into the equivalent of two at which point I can decant and put the 1.82 liters of wort from step 1 in there and call it a day. So what I do is fiddle around with the gravity on the starter until the numbers below tell me that I need exactly 2 yeast packs without a starter (in my example, this is 1.040, this doesn't matter for anything I am just using the calculator backwards to figure out what I need to know). In addition to telling me a 1.040 wort needs 2 yeast packs, which I don't care about, it also tells me that 1 yeast pack in 1 liter of starter is the equivalent.

3. So now I just work backwards. I pitch my yeast pack into 1 liter of wort, producing the equivalent of two yeast packs. I chill and decant and then add 1.82 liters of fresh wort. Now I have as much yeast as 4.8 packs or a 4.5 liter starter with 1 pack, which is what I need for my beer.

ETA: Note that I only need 2.82 liters of wort in a two step process to get the same number of cells as 4.5 liters of wort in a one step process. So if you do 2+2+2 you will end up with way to much yeast (in fact 2+2 might be very close to enough).

 

[remilard]

Any suggestions for getting more oxygen to a starter that's not on a stirplate? I've had a couple of batches of yeast harvested from a while back, and they don't seem to take off like they should. I'm not sure if they've died off, aren't getting enough food, or not getting enough O2.

Stir plates do more than provide oxygen. They remove c02 and they agitate the yeast. If you use a 2 liter PET soda bottle, you can do pretty well to remove c02 periodically by shaking (to release c02 from solution), squeezing the bottle to remove all of the gas from the headspace (when you let it go, it will draw air back in) and then shaking again to incorporate the air that is no in the headspace and the oxygen that is in it. Just keep the 2 liter bottle next to you and do this as often as you care too. You'll need a gas permeable cover, eg foil.

 

[Dos_Locos_Brewery]

The PET soda bottle is a great, practical suggestion, but I also think that an O2 tank + SS aeration stone is a reasonable, not too pricey, brewery addition. The one Revvy shows is great, but the standard stone without the long SS tube extension is fine (although now that I've seen the one from Williams, I might just have to have one). Also, you can (and should) calculate the ideal yeast population, but that's only an estimate, and only part of the picture. Yeast strain and history (respiration/fermentation cycles, O2, nutrients, etc) can throw a lot of variation into your ferment.