starter question

I've brewed a few batches usually using a starter where I boil a cup of DME in a qt of water and then pitch an "activated" wyeast activator pack a couple days before. I pitch this entire starter when the wort is ready.

I'm now preparing to do a couple big beers (an IPA and a Tripel). I'm not sure that my normal starter is enough. Should I use a larger starter? If so, do I pitch the whole thing or just the sediment?

Try this and this and of course, the forum search function.

As EricCSU stated, Mrmalty is a great resource for all things starter related. I have done a little research on pitching starters. Mr Malty suggest pitching at high kreausen (18-24 hours after preparing the starter) which is normally what I attempt to do, however, for larger starters you may have to "step-them-up" which would mean you either have to have a container large enough to continually add wort "step-ups" to reach the desired wort volume for the amount of yeast, or chill and decant the wort from starters in a smaller vessel and then add fresh wort to increase yeast population.

It is ideal to have the correct size vessel to continue adding wort to, simply because chilling and decanting off wort in a smaller vessel and then adding fresh wort will not have the exact same effect. Yeast population requires a certain amount of room. For example, if you were to have say a 2 liter container and make a 2 liter starter then chilled and decanted of the spent wort, then added 2 liters of fresh wort, you would not have the same yeast population as if you were to have a 5 liter container, and "stepped-up" the starter wort from 2 liters to 4 liters. Once again, it has to do with space, yeast need a certain amount of space to reach a particular population.

Using the 2 liter container and chilling, decanting, and adding fresh wort will definitely increase the yeast population, just not as effeciently as when using a larger container, and of course the yeast population cannot be maximized as well.

As far as pitching at high kraeusen or chilling and decanting goes, I think both have their benefits and drawbacks. The argument can be made that pitching at high krauesen means you are pitching all of the starter wort which may contain off-flavors due to the warmer fermentation temperatures of the starter. Remember starters are for growing healthy yeast, not for making good beer, having said that, pitching 1-2 liters of starter wort into ~19 liters (5 gal) of wort will have a negligeable impact on flavor, and if you practice the "extended primary" technique where you leave the wort in the priamry for 3-4 weeks, many of the possible off-flavors created during fermentation as well as from the starter will be cleaned up to an extent by the yeasties.

As for chilling and decanting, the benefit is that when yeast go dormant they store up energy (glycogen reserves) which prepares them for the next fermentation. Glycogen reserves are a source of energy for the yeast which helps during the initial phase of fermentation (reproduction) and affects the cells ability to uptake nutrients. Which means that the yeast will have a little more fuel during the aerobic phase before fermentation begins.

Yet, pitching at high kreausen means the yeast are in action and already rockin, which reduces lag times, either way I don't necessarily think that one technique is better than another. As I stated earlier, arguments can be made for and against both, but either will work just fine. You may run into a situation where your starter has been growing for 48 hours and brew day is going to be pushed back a week or two, obviously the logical thing to do is place that starter in the fridge, and when brew day does fianlly arrive decant off the wort, and allow the slurry to reach room temps before pitching it.

Sorry for the winded response, hope this info helps.

I also have a related question to tag along onto this thread.

I heard Jamil talk about making bigger beers, and you may not want to add a huge volume of starter to your wort. One solution he offers is to let the starter ferment to completion, and then put in the fridge for flocculation. Then you can decant off the liquid and just pitch the slurry that settles (that's how I understand it, at least).

What I don't understand is the relationship between this method and repitching slurry that you collect from the bottom of a primary fermenter. If I use the method above, then shouldn't I use the "Repitched Slurry" part of the Mr Malty calculator?

Or has anybody done this experiment: use the calculator to determine what size starter you need for your batch. Then do the refrigeration/decant. Then measure the volume of yeast slurry you collect. Then run the calculator for Repitched Slurry and see if the volume of yeast slurry recommended is what your starter actually yielded.

kanzimonson said:

What I don't understand is the relationship between this method and repitching slurry that you collect from the bottom of a primary fermenter. If I use the method above, then shouldn't I use the "Repitched Slurry" part of the Mr Malty calculator?

Or has anybody done this experiment: use the calculator to determine what size starter you need for your batch. Then do the refrigeration/decant. Then measure the volume of yeast slurry you collect. Then run the calculator for Repitched Slurry and see if the volume of yeast slurry recommended is what your starter actually yielded.

Click to expand...

I do this when I'm concerned with color or for large starters that will significantly add volume to my fermenter. It is not the same a re-pitching the slurry, because the slurry after a primary fermentation will contain a lot of dead yeast and waste products, so you have to rinse the yeast to separate the crap from the viable yeast.

When you make a starter, then put it in the fridge the yeast will flocculate and fall to the bottom, but probably 99% of those yeast are healthy and viable. You can pour off the supernatant, and then pitch this entire yeast mass, and it will be the proper yeast population you need.

Glorious! I love getting a clear answer!

Follow up: if I rinse yeast from a primary, separate into containers (I'm thinking about putting into beer bottles and capping), and refrigerate, do you recommend making a starter from this yeast? I'm sure there are a lot of factors here, but I've seen threads where people just warm up the rinsed yeast and directly pitch into their wort. And they seem to be doing this after at least a couple weeks in the fridge.

And do you treat rinsed yeast as repitched slurry using the calculator?

kanzimonson said:

Glorious! I love getting a clear answer!

Follow up: if I rinse yeast from a primary, separate into containers (I'm thinking about putting into beer bottles and capping), and refrigerate, do you recommend making a starter from this yeast? I'm sure there are a lot of factors here, but I've seen threads where people just warm up the rinsed yeast and directly pitch into their wort. And they seem to be doing this after at least a couple weeks in the fridge.

And do you treat rinsed yeast as repitched slurry using the calculator?

Click to expand...

I think there is a sticky for rinse/washing yeast, buy I think the take home message if you want to store yeast from your slurry are:
Use cool water that has been boiled to sterilize and remove O2.
Store them in mason jars in the fridge, (just to avoid any bottle bomb problems.)
Use them in a few weeks after storing, no longer than a few months.

Yes I treat rinsed yeast as re-pitched in Mr.Malty calculator for a Slurry has a slider to help you determine the approximate number of yeast, according to the thickness of your slurry. I put this closer to the thin side when I rinse my yeast.

Wow, thank you all for the information. I see that its not a simple question to answer - off to Mr Malty I go for more information.