Ranching yeast from a bottle - time line

[Nyakavt]

If I go with the two steps I've planned, will I see any impact in my beer?

I'd be more worried about infection from pitching so little yeast in half a liter of wort- not enough to out-compete the nasties, than from an extra step or two. At the very least, add a 50ml step. Then 400ml, then 1L .

Exactly, this is why you do smaller steps first. The biggest I've tried is 150mL for the first step, I'm sure going bigger works with reasonably healthy yeast, just haven't tried it.

There also comes a point (according to the mr. malty calculator) where you are using a lot of wort to grow a small amount of new yeast, so it may actually be more costly to take bigger 1st steps. For example, if you have the same amount of yeast sediment as a bottle of Sierra Nevada (1 million cells/mL), that's roughly 355 million cells. The mr. malty calc sets starter sizes between 1-8L/100 billion cells, or 1-8mL/100 million cells. A 400 mL 1st step is 112 mL/100million cells, over 10X the max recommended for 'efficient' use of wort for cell growth. It still grows new yeast, but you won't grow 8X more yeast than a 50mL step even though the starter is 8X bigger. Give it a try and let us know, it would be good to correlate with the calculator on a small scale.

I'm planning on doing it from a commercial bottle of Summer Lightning. I don't want to do so many steps because it takes time, costs money and increases the chance of infection. I also don't need 2l of starter. If I go with the two steps I've planned, will I see any impact in my beer?

You need to make sure the two steps grows enough yeast for the batch, that's your main risk. I don't know how big of a starter is required to get you up to the cell count required, but I think it's in the 1.5-2L range on a stir plate for the average beer based on previous starters I've done. Remember you're not starting with 100 billion cells like on the liquid tab of the mr. malty calculator, so those starter volumes do not apply in this case. Just look at the volume of slurry and estimate from that, it's the only reliable way to know how much yeast you're pitching without a microscope.

I plan to pitch the 1 litre into the batch at high krausen but dont want to pitch the smaller starter into the 1 litre at high krausen because i dont know when ill need the yeast. I figure if I let the smaller starter ferment out fully, ive got a 7 day grace period in which I can pitch to the 1L stater at any point.

You want the 'growth' steps to ferment out fully if you plan to decant, so I would prefer to have the yeast to the desired cell count then cold crash and decant right before pitching. But if you're not decanting then what you propose is fine, maybe even preferred since the yeast will be more active. Make sure you give it at least 18 hours before pitching into the main batch so it can grow enough new cells from your 1.5L step.

If im pitching the whole litre into the batch and not the resultant slurry, am I right to use the liquid yeast tab on mr malty?

No, the most appropriate tab for you is the 'repitching from slurry' since you don't know how many 'liquid yeast packages' are in your starter.

[Chunk]

Ok, back on this subject. When building the culture size up, is it better practice to wait until fermentation is complete before pitching into a larger amount of wort, or is it better to do it at high krausen?

[Nyakavt]

Ok, back on this subject. When building the culture size up, is it better practice to wait until fermentation is complete before pitching into a larger amount of wort, or is it better to do it at high krausen?

I've always waited 24 hours before the next step up, which is letting it ferment out if the step size is reasonable for the cell count. No idea which one works better though. The exception is the first step - depending on yeast age it can take several days to show a krausen so I let that one go a bit longer if necessary.