Back to Shopping at NorthernBrewer.com

When is a yeast starter done?

I made a large (2.5 gallon) starter of Wyeast 2206 for a 10 gallon lager batch. I made it Thursday Afternoon. Been shaking it several times a day since.

I need to step it up again before brew day (the 10th) to get enough cells for two fermenters of a lager.

How do I know when this one is done?

wish i could help you. figured i’d post so it doesnt look like no one cares

Haha! It’s only been an hour. I’m not too worried that I won’t get a response :cheers:

admit it, you’ve checked the thread atleast a dozen times in the past hour looking for a response. hell, i do when i start a thread. i demand answers!!! :cheers:

You can usually tell because the krausen will drop. On stir plates this can be tough as the starter will develop a ring of foam from the constant agitation. In this case I look for bubbles of CO2 raising up the sides.

Even when on a stir plate I stop it for a few hours here and there just to see what is really happening. Swirling hard by hand, I can tell how active it really is. When it is really done it will start to settle and clear at the top.

I just read about this in Yeast
http://members.brewersassociation.org/store/detail.aspx?id=499
. Turns out there are two spots you can choose:

You can pitch it right after it’s consumed all the starter wort sugar it’s going to consume, and before the yeast has had a chance to start going into dormancy. The main drawback here is that you shouldn’t decant if you do this. The least healthy yeast tends to settle out first and if you decant at this stage in the game you’ll be pouring a lot of the most healthy yeast down the drain as well as all the less-flocculent yeast that can make sure you reach terminal gravity. The main advantage here is that it’s the only way to go if you’re trying to revive a stuck fermentation. The higher alcohol and lower (and worse) sugar in a partially-fermented beer will inhibit the yeast coming out of dormancy, but you avoid that problem if you are pitching yeast that’s already active.

If you choose instead to let the yeast settle out so you can decant and pitch, be sure to give the yeast plenty of time. They need at least 12 hours past the end of active fermentation to build up their glycogen reserves, which they’ll need to do a good job on your beer. And if you’re planning to decant, they’ll also want some time to flocclate first. A couple days in the fridge doesn’t hurt here. Apparently it’s especially important to be careful about decanting too early if you’re planning to re-use yeast, because yeast evolve quickly and if you create a strong selective pressure against the yeast that are willing to stay in suspension they will respond to it over successive generations.

The answers above look great. I use a pretty pragmatic approach. I plan to prepare the yeast starter a few days before I brew. I shake the flask intermittently (quite often when I am around) to make sure there is starter is oxygenated. The first day or two looks like active fermentation. On day two or three, a healthy looking yeast cake starts to form. I can then make the decision to pitch or refrigerate and decant if needed.

My signal is the formation of a “thick” yeast cake on the bottom of the flask.

Mr Malty also has some nice yeast tools. http://www.mrmalty.com/yeast-tools.php

very rookie question perhaps, but I assume decant means pouring off the top layer of liquid, with the assumption the yeast has settled to the bottom?

I am trying my first yeast starter I think this weekend or next. I have brewed may be 20 + extract kits, so I have some experience but nothing like many of you. What is my best course of action (or how much dies it matter?). let it settle and pour off the top? or just pour the whole thing in (I am using light DME)

[quote=“stompwampa”]I need to step it up again before brew day (the 10th) to get enough cells for two fermenters of a lager.[/quote]Why didn’t you just make a 5-gal starter batch to begin with?

Exactly. Pour off most the liquid. Leave a little in the flask so you can swirl it to get the yeast back into suspension for easy pouring.

For delicate beers I always decant. Especially if you’re aerating it well the liquid from a yeast starter can come out tasting rather. . . um. . . not so great. Not really something you’d want to be coming through in the flavor of your beer.

For strongly-flavored beers, I’ve pitched the whole starter without a problem. I’ve also had brewing buddies give me dirty looks while I’m doing it.

I am glad I asked - I was thinknig the whole purpose of using the light DME was so that it wouldn’t have a dramatic impact on the taste. having said that, I was already thinking puring 1500 mL or whatever of it into a 5 gal batch would have to have some effect.

I will do just as you suggested. I plan on letting it go for 1-2 days, then settle for the last few hours and decant as much as I can.

thanks again

[quote=“fullhousebrew”]I am glad I asked - I was thinknig the whole purpose of using the light DME was so that it wouldn’t have a dramatic impact on the taste. having said that, I was already thinking puring 1500 mL or whatever of it into a 5 gal batch would have to have some effect.

I will do just as you suggested. I plan on letting it go for 1-2 days, then settle for the last few hours and decant as much as I can.

thanks again[/quote]

A few hours ain’t gonna do it. Give yourself enough time to do it right. Minimum 2-3 days to fully ferment if it is fresh yeast, and then cold crash for two full days. I am making a starter now for a Sunday brew day. Friday morning I will put in the fridge.

ok, I guess I was going by the NB video about doing it 1-2 days in advance. I will plan on following your timeline (plus I will admit I need to do some further reading - this was just a few quick youtube videos)

As a point of clarification, I always decant as much as possible because I don’t want any nasty, room temp fermented, non hopped, short boiled old beer in my beer, if I can help it.

Also for older yeast or older harvested yeast, allow a couple extra days or even more if you need to step up.

Stepping up may only take a day if you are going from 2L to 4L. They are active and eating fast.

If you cold crash in the fridge for a day most of the cells will drop.

When I step up, I usually cold crash, decant and then step up

sorry. but…

Step up???

[quote=“fullhousebrew”]sorry. but…

Step up???[/quote]

Mix up another starter wort and add it to the complete stater yeast cake after decanting. Effectively doubling, or more, your yeast cell count again.

got it. sorry for hijacking the thread a it but has been a lot of good info.

for a 5 gal extract I am thinking I will stick to just doing a single starter for now until maybe I have the hang of it. that alone is more than I was doing for the 20 + I have already brewed.

Back to Shopping at NorthernBrewer.com