Starter step up ratios???

[artguy]

I've only been using liquid yeast and starters for my last 6-7 batches or so, and for all of them I've only needed up to a 1.5 liter starter, so I've pitched either a smack pack or prior slurry directly into the full starter volume of wort. Now I want to make a larger starter, and some of the info out there is pretty contradictory as far as I can tell, so input would be appreciated.

Mr. Malty says about stepping up a starter that "Five to ten times the size of the prior step is considered correct." It seems like he is saying that a 1 liter starter needs to be stepped up with at least an additional 5 liters, right? He also states that a vial or smack pack should not be poured into a starter of less than 1 liter. So, taking those two bits of advice together, how do you do a 3 liter starter? Make a 1 liter starter and pour half of it into a 2.5 liter starter? Just wondering...

 

[suprchunk]

Well, if you are saying you have been using opposite of what Jamil says, why would you need validation? If 1.5L is working for you, why do you think you all of a sudden need to start listening to him? I use what works for me. I haven't used these online calculators in the past, when online wasn't available, and I've got decent beers. But if you want consistent batches (if you are trying to make the same beer exactly the same every time) then there IS a science behind it.

 

[artguy]

Well, if you are saying you have been using opposite of what Jamil says, why would you need validation? If 1.5L is working for you, why do you think you all of a sudden need to start listening to him?

No, a bit of a misunderstanding here. I've been using Jamil's recommended starter size with success and trust his advice. My bad if I sounded like I was challenging it, which wasn't what I meant at all. I just am not clear his instructions on stepping up a starter, so I'm trying to understand whether I'm reading correctly that you really need a 1:5 to 1:10 ratio when stepping up, because 1 liter to 5 liters seems like a big jump for a starter (and I speak from complete inexperience on this...haven't done it yet, which is why I'm asking).

 

[suprchunk]

He is not saying the next step needs to be that large. He's saying if you want a lot of yeast to step it up that much. He is also saying you could pour directly into 2L. So to answer your question, if it was serious, about the 3L starter - you could do as he suggests by pitching from 1L to 4L. But here's the catch - you don't have to go to 4L you could go to 3L instead, thereby giving you the 3L starter you wanted.

 

[derekm]

No step up here. He means make a 3L starter and pitch into that.

 

[artguy]

No step up here. He means make a 3L starter and pitch into that.

Ah, thanks. Is there a specific volume at which it becomes necessary (or at least advisable) to "step up" a starter, or is stepping up just an option that grows more yeast cells per volume of starter?

 

[SpanishCastleAle]

The reason he says to use at least a 1L starter is because if the starter is smaller than that you'll be over-pitching the starter* too much which can lead to yeast that is depleted of nutrients.

So if you make, say, a 1.5L starter and then want to step it up; you want to step-up enough such that you don't over-pitch the starter too much and get yeast that is depleted of nutrients.

But the amount of yeast in a smack-pack/vial should be plenty to just make a 3L starter in the first place. Starting smaller and then stepping-up would probably be worse than just making a 3L starter to begin with.

* - all this is contingent on the health/viability of the yeast in the vial/smackpack. If you have a really old vial/smackpack then you are starting with less yeast to begin with and can use smaller starters and not be over-pitching them.

 

[kryolla]

I dont get too involved with the ratios but I would do either a 1l or 1.5l starter and step up to a 3l.

 

[artguy]

So if you make, say, a 1.5L starter and then want to step it up; you want to step-up enough such that you don't over-pitch the starter too much and get yeast that is depleted of nutrients.

Thanks, that makes sense.

 

[bja]

so I'm trying to understand whether I'm reading correctly that you really need a 1:5 to 1:10 ratio when stepping up, because 1 liter to 5 liters seems like a big jump for a starter (and I speak from complete inexperience on this...haven't done it yet, which is why I'm asking).

I believe the 1:5 to 1:10 thing is for when you are making a starter from a slant.

 

[SpanishCastleAle]

I believe the 1:5 to 1:10 thing is for when you are making a starter from a slant.

It's referring to stepping-up although it may apply to slants as well.

From the Mr Malty 14 Essential Questions About Yeast Starters:

Q: When increasing a starter in steps, should the steps be a certain size?

Yes, but there is plenty of leeway in the size of the steps. A “step” is when you take an active starter and increase the volume with more wort. Brewers do this to increase cell mass, while keeping the rate of growth consistent.

The size ratio of one step to the next can affect the health of the yeast and the amount of cell growth. A very large step can result in a change in yeast metabolism, where the sugars that are fermented last can fall out of favor with the yeast. The yeast become lazy and subsequent generations can become lower attenuating.

Making a greater number of small steps increases the chance of contamination. Every transfer, every feeding, every bit of handling you do increases the chance of contamination. Five to ten times the size of the prior step is considered correct. You should try to balance the practical considerations of handling, sanitation, and cell growth.

I dont get too involved with the ratios but I would do either a 1l or 1.5l starter and step up to a 3l.

I addressed this above but here's the section of that same article that mentions it:

Q: I’ve heard that too small or too large a starter can be bad for the yeast. How is that possible?

Parker says putting a fresh vial of yeast into 500 ml of wort and letting such a small starter go to completion can actually leave the yeast less ready to ferment a batch of beer. The yeast do not rebuild their reserves and have very little increase in cell mass.

The minimum starter size for significant yeast growth from a vial or pack of yeast is 1 liter. One vial or pack into 1 liter results in approximately a 50% increase in cell mass.

Some brewers make a small starter volume (500 ml or less) with the sole intent of “waking” the yeast. When making small starters, it is best to pitch the entire volume at the height of activity.

So considering that a starter made from a vial/smack-pack should be at least 1L, it stands to reason that if you've already made a 1L starter that subsequently pitching that into another 1L starter (or even 3L) would be way over-pitching it leading to "the yeast not rebuilding their reserves and having very little increase in cell mass." Unless it's very old/mistreated, a vial/smack-pack should be plenty to just make a 3L starter to begin with.

 

[kryolla]

My take on things, the reserves are only needed while they adapt to the wort and are able to use it or sustain them after all wort nutrients are used up and a starter is to increase cell count so I don't think there is any harm by stepping it up 100% or more.

 

[mattldm]

I made a 32oz starter with WLP380 and let it ferment out. I want to pull off part of this starter to so another batch of beer at a later date...

So how should I go about this? decant the wort and split up the yeast? or just shake it up to mix it up and then divide it into two jars?
thanks

 

[petep1980]

Mr. Malty I think uses some funny math.