Yeast starter step up question

[morethanworts]

I read online recently that if you step up a starter, it should be by at least 5 times the first step, the reason apparently being that the yeast need to get used to increasingly big worts. For the life of me, I can't find where I read it now.

I only have a 2 litre conical. I need to get to around 450 billion cells for my 19L of 1.079, going by at least one source. It's quite easy to get up to that figure, starting with a 100 billion cell Wyeast Activator pack, with just one big starter (too large for my 2L conical), or by doing two steps in the same conical, decanting after the first one. BUT, the second step would not be 5x the first, to get to that cell count. Does this matter? Is the advice I read above correct? Every other source I can find just says to do two similar size steps and decant in between, which would certainly get enough cells.

 

[brewtim]

I read online recently that if you step up a starter, it should be by at least 5 times the first step, the reason apparently being that the yeast need to get used to increasingly big worts. For the life of me, I can't find where I read it now.

I don't understand the reasoning behind this, after all both Wyeast and White Labs recommend pitching straight from the packet into 5 US Gallon, a starter being optional.

All a starter is doing is growing the quantity of cells you want/need for the style and gravity of beer you are making (and checking the viability of the yeast), there are probably some effects by not doing it in a certain way, but on a homebrew scale it probably doesn't make that much difference.

If a second step had to be 5 times the first step and you want 400 billion cells then wouldn't you need 80 billion cells from the first step to make that work? What if you have more than 80 billion cells from the first step? It all sounds too complicated :wha: :hmm:

 

[Good Ed]

commercial breweries tend to use the 10x rule, but as homebrewers on a smaller scale it doesn't really matter.

according to Mr Malty for 19L of ale at 1079 you need 271bn cells; given that Wyeast is the same as WLP and that there are ~100bn cells in a pack/vial, you would get ~300bn cells by pitching the pack into a 5L starter; alternatively you could do a 2L starter with the pack, when finished decant off spent wort and use the yeast with another 2L starter to get your ~300bn cells.

 

[morethanworts]

Thanks very much for these helpful replies. :thumb: :thumb:

It sounds like I should concentrate on getting the right cell count, above all else. Wyeast's own site just says >18M cells/ml when over 1075. Using their own pitch rate calculator, two 1L steps with a stir plate should get me 18.67m cells/ml in 19L (working between US gallons and Litres on the site).

I'm using Wyeast 3787. Seeing that the 1085 beer (Belgian tripel) that has just gone into secondary tastes great and got down to a fantastic 1009 just with a straight 1.25L starter (although it took 3 weeks despite stirring every couple of days after week 1), I'm guessing two 1L steps should more than do the job in 1079. I'd just like it to get down a little quicker this time.

I think I may be at 88% viability (manufactured 3/10) so I might go to two 1.25L steps, which is about all the headspace will allow in my conical with that yeast.

Thanks again.

 

[brewtim]

I think I may be at 88% viability (manufactured 3/10) so I might go to two 1.25L steps, which is about all the headspace will allow in my conical with that yeast.

Headspace on a stirplate should not be much of an issue (regardless of yeast), the constant stirring knocks the CO2 out of solution and prevents any significant foam buildup, I reckon 1.75L size would be comfortable (I've not yet gone beyond 1.5L in a 2L conical).

Even a 3L barely has a head buildup if on a stirplate (in a 5L demijohn).

Fermenting in a 30L fermentor that is not stirred is a different matter, massive replication and no stirring = large foam buildup.

 

[Good Ed]

yes cell count is important, but without lab equipment we are just trying to get thereabouts, most important however is yeast viability, and all we can do, again without lab equipment, is to give it our best shot using best practices.

as a general guide the pitching rate for ales is; cells to pitch = 0.75 million x millilitres of wort x degrees Plato of the wort (OG divided by 4), and for lagers use 1.50 million cells.

another useful thing is to measure the slurry of a WLP vial as this is ~100bn cells, you can then use this as a guide when producing starters and stepped starters.

I think you'll be good with your plan :thumb: One of the days I'll get round to making a stir plate, at the moment I just use a 5G demijohn

 

[morethanworts]

Thanks again, both.

I've duly made a 1.25L starter, which is sat in the brew fridge at 20C. I'm hoping to get the step up done and settled/chilled ready to pitch on Friday evening, so I need it to get its skates on. I might be losing a few buoyant cells in decanting otherwise. The fridge will be working hard this week.

My self-built stir plate does struggle a bit when the wort is thick with yeast, even though it's doing a good whirlpool right now at the start. This is how it was last time around its highest:

That said, 3787 is know as a REALLY krauseny, top-croppy yeast. It pumped up over 13L of krausen at one point (20L batch in 33L FV) as it mushroomed out of the fermenter in primary last time :shock:

 

[brewtim]

That said, 3787 is know as a REALLY krauseny, top-croppy yeast. It pumped up over 13L of krausen at one point (20L batch in 33L FV) as it mushroomed out of the fermenter in primary last time :shock:

Ah OK, I've not seen that much foam in my starters.

Did you lose 13L worth of beer with this yeast that time?

Yeast is a strange beast, I've just skimmed my Belgian (WLP570) after the first 24 hours and observed what was happening at the surface, it looked like the wort was alive with swirling masses of bubbles breaking through, amazing!

 

[morethanworts]

No - I didn't lose 13L beer. I just mean the krausen filled 13L headspace and still overflowed. FV was only at 18 or 19 C at the time. I will be interested to see how a 'normal' ale yeast performs on the stir plate. 3787 (same as white labs 530, I think) is the first liquid yeast I've done.

ADDED: This morning's starter doing just the same (below) I can hear the 'plopping' sound that comes when the whirlpool is there OK, so perhaps this excess krausen is mostly the WY3787 rather than a stirring problem. It really is a monster!