Very Large Starters

[pirateagenda]

Who has some solutions for very large starters up up to 2000B cells for 120 litre batches?

currently my best solution is 2.5L stirplate starter stepped into a 15L batch of starter beer. That's pretty time consuming though and seems like either a waste of wort if I used the shake method and pour it out, or a waste of time if i let it ferment naturally and keep the 15L.

 

[awfulknauful]

Not really a waste of time, or waste of wort, you are increasing the cell count of the yeast and you get to keep the beer, cant think of any other option.

 

[Black n Tan]

I assume you are brewing a lager or big ale? What equipment do you have? Drauflassen may be a good option to reduce the size of the initial starter you need. http://braukaiser.com/wiki/index.php?title=Drauflassen

 

[pirateagenda]

if I shake it up to oxygenate through fermentation to maximise cells and speed it up it's going to taste like crap, and if i don't it's going to take 5-10 days to ferment out, taking up fermenting space.

 

[pirateagenda]

I assume you are brewing a lager or big ale? What equipment do you have? Drauflassen may be a good option to reduce the size of the initial starter you need. http://braukaiser.com/wiki/index.php?title=Drauflassen

Not really, mostly ales and the occasional lager. Just a lot of volume needs that much starter. a 5% Pale Ale would probably need around 1500B, lager obviously a lot more.

I pressure ferment in kegs so unfortunately the drauflassen might be a bit of a pain in the rear

 

[Black n Tan]

What flasks do you have? If you are using fresh yeast ie. not from a previous batch, then you will get away with a lot less yeast than you have estimated are required. You may get away with 0.5-0.75 million cells / ml / degree plato which will reduce your yeast requirements to 750-1,100 billion. I can get about 1,000 billion with a 1L then 5L step starter. Drauflassen is still an option in pressure vessels eg. just don't cap the ferment in the first 24 hours. You could also do a 2.5L starter and then a 10L starter in the keg and transfer your 120l on top. Options a plenty.

 

[Wobbly74]

Last couple of batches I've done I've created an active starter by rehydrating yeast in a flask and then tapped off some wort and put on a stir plate, then pitched it 4-5 hours laud into the fermentation cube whole. In theory could you use more wort to step this up over a few days and then pitch the resultant starter whole into the batch?

If the yeast are kept in their propogation stage and are consuming the oxygen from the starter agitation continuously, would this avoid oxygenation spoilage?

 

[RobW]

As per Wobbly (above):

Try growing your starter to the second last step up you have calculated you need, then crash chill it a couple of days before you need to pitch.
On brew day pour the wort off the starter and replace with the volume of your brewday wort you would have used for the last step up.
Aerate this and let it ferment until it starts to krausen, then pitch it straight into the rest of the wort.

Cheers

Rob

 

[MHB]

When we talk about yeast populations Exponential Notation makes life easier.
Both Wyeast and White Labs claim to have around 100 Billion cells (I have seen counts that average closer to 110-130 Billions in very fresh samples) per package.
100 Billion can be expressed as 1*10^11 (100 000 000 000).
You don't give a batch size, but if we use the default 23L in the fermenter, and a beer aiming at ~5% ABV, we are looking at an OG of around 1.050 or 12.5oP (Plato)
The two standard ranges are expressed as cells/point of Plato/mL of wort
For Ale the recommended range (commercial brewing) is 0.4-1.0 Million cells/mL/oP
For Lager about 50% higher 1.0-1.65 Million cells/mL/oP

So lets say we choose a mid range pitch for an Ale at 12.5oP (~0.7M/oP/mL) in 23L or 23 000mL
(0.7*10^6) x 12.5 x 23 000 = 201 250 000 000 or 2*10^11. Basically its about 2 packs of Wyeast or White Labs.

In a really basic starter without ongoing aeration (timed doses of Oxygen is the nuts) you really would be lucky to get more than 80 million cells/mL, in a stirred oxygenated starter maybe 100 million cells/mL.
Lets say your expecting 80 million, you want 200 billion in total so: -
2*10^11/8*10^7 = 2515.625mL (2.5L) starter.

Mark