Yeast starter and yeast cake question

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BrosBrew

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Alright, I feel dumb, I know this has been asked before but I couldn't find it. I have a white labs Irish ale yeast (liquid). I'm gonna do a honey oat stout. The listed SG is around 1.090 so I think a starter is in order due to the high gravity.... How do I do it?

Also, my Oktoberfest has been in the primary for 15 days now and has a nice yeast cake on the bottom. It is a Windsor yeast. Could I just rack my Oktoberfest to a secondary, then just put my stout right on top of this yeast cake and use that as my starter then also add my Irish ale yeast? Would this work well without adding a lot of weird flavors?
 

Chello

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For the starter just basically make a small beer, but no hops are necessary. Take maybe 3oz of DME and boil it in a quart or so of water for 15min. Cool it just like you would your beer and then pitch your yeast. Put an airlock on it and let it ferment for 24-48 hours. Then pitch that into your beer your brew.

You can reuse a yeast cake for your next brew if you want. I do it all the time, but i would not pitch a different yeast after using a yeast cake. The caked yeast outnumbers the new yeast by such a large margin, it would be a waste of $6.50 and you would not notice any of the Irish Ale characteristics at all.

hope this helps.
 
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BrosBrew

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do you think the Irish ale will bring enough to the table to justify the use of a Irish ale yeast rather than a windsor british ale yeast?
 

carnevoodoo

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For the starter just basically make a small beer, but no hops are necessary. Take maybe 3oz of DME and boil it in a quart or so of water for 15min. Cool it just like you would your beer and then pitch your yeast. Put an airlock on it and let it ferment for 24-48 hours. Then pitch that into your beer your brew.
Actually, you should absolutely not use an airlock on a starter. The idea of a starter is to build a population of yeast. Reproduction of yeast requires oxygen and the airlock will quickly push any and all oxygen out of the vessel you are using. Most people suggest a piece of sanitized, loose-fitting tin foil.

The airlock is good for your fermentation because a) it keeps infections out and b) once the replication phase is complete, the alcohol production phase is all anaerobic.
 

springer

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Actually, you should absolutely not use an airlock on a starter. The idea of a starter is to build a population of yeast. Reproduction of yeast requires oxygen and the airlock will quickly push any and all oxygen out of the vessel you are using. Most people suggest a piece of sanitized, loose-fitting tin foil.

The airlock is good for your fermentation because a) it keeps infections out and b) once the replication phase is complete, the alcohol production phase is all anaerobic.

wouldnt this only be true when the yeast starts to produce CO2? And once that happens unless you force 02 into solution (airstone or shaking) all that would be in the vessel is CO2 whether there is a foil cap or airlock on it because CO2 is heavier than O2 .
 

carnevoodoo

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wouldnt this only be true when the yeast starts to produce CO2? And once that happens unless you force 02 into solution (airstone or shaking) all that would be in the vessel is CO2 whether there is a foil cap or airlock on it because CO2 is heavier than O2 .
Nah. There is still air exchange going on. Sure, without a stir plate, it is minimal, but it still happens. With a stir plate though, you create a small vortex which will suck in air and it keeps the yeast in suspension which is why they're so handy.
 
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BrosBrew

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Can I make a yeast starter in my 6.5 gal carboy, then pour my wort and water right on top of it when I brew? Does the yeast have to be poured on the top of the wort to get a top fermentation like the ale yeast is?
 

Kingum

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wouldnt this only be true when the yeast starts to produce CO2? And once that happens unless you force 02 into solution (airstone or shaking) all that would be in the vessel is CO2 whether there is a foil cap or airlock on it because CO2 is heavier than O2 .
Gases mixed based on partial pressures (pp) and they flow from high pressure to low pressure. If there is only CO2 and no O2, the pp_O2 = 0 and the oxygen in the atmosphere will diffuse into the vessel. An airlock doesn't give the O2 in the atmosphere a path to get in.
 

hardrain

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Can I make a yeast starter in my 6.5 gal carboy, then pour my wort and water right on top of it when I brew? Does the yeast have to be poured on the top of the wort to get a top fermentation like the ale yeast is?
I'm sure you'll get someone who says this is okay, but I wouldn't recommend it. For starters, it means you won't be able to drain off the starter wort you used therefore it's going to be part of your beer. Any old juic bottle will work just fine, put a sanitized piece of plastic wrap on the top with a lose rubber band around it and you're good to go. Plus, if you can always put that in the fridge if you need to wait a day or two after the starter is done...something that would probably be tough with your carboy.
 
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