stirring plate and liquid yeast

[docmoran]

Is a mixing plate/magnetic stirrer needed with liquid yeast or is it just dry yeast starters that gain benefit from them???? Read post that good aeration kit plus starter by stir plate was the bomb in healthy fermentation actiivty/

 

[Clonefarmer]

Only liquid yeast require starters. From what I have read the stir plate helps immensely.

 

[beersydoesit]

Check out Mr. Malty yeast pitch rate calculator to see what a stir plate does for you.
Mr Malty Pitching Rate Calculator

You don't have to have a stir plate, I don't, but they improve the oxygenation of the starter and promotes yeast growth. (The whole point of a starter).

 

[docmoran]

Does that mean liquid yeast cant be just put into wort as is?? Doesnt have to have a starter - just better to do so?? thanks doc

 

[JuanKenobi]

If you are using White Labs vials or Wyeast Activator smack pack you CAN just pitch it into 5 gallons, but you are invariably underpitching. Making a starter is highly recommended, especially with high gravity brews. If you have a Wyeast Propogator pack then you need to make a starter. They have less cells and are meant to create a starter. A pitching calculator, like MrMalty, will give you the ideal pitching rate. It's all about the best case scenario for your fermentation. A proper pitching rate can reduce lag time, help attain complete attenuation, reduce ester production, etc. I made my first dozen or so batches just pitching White Labs vials right into the wort and made very good beer. However, I ALWAYS make a starter when using liquid now.

 

[docmoran]

kenobi,

I am sold on doing it. I like the White lab product and like the liquid over dry.. Have been using 2 vials straight into wort so dont know cost issue but am more interested in better pitching -- I do 5 gallon batches -- is the 1000ml ok or get the 2000ml flask?? thanks, doc

 

[JuanKenobi]

I just use a 1/2 gal growler. I'll probably get a flask when my stir plate finally comes together, but I'm not the best person to ask about which size is better. If I had to guess I'd say get the 2000ml so you can make a wider range of starter sizes.

 

[chumprock]

Is there any good basic explanation of that pitching calc? I thought I was kind of smart but that thing confounds me..

Example, Making an Ale with a 1.056 OG for a 5.5gal Batch says I need 215 Billion cells (ok?), but what I dont get is it says I need 2.33L of starter?

Is that 2L of slurry total, or 2L of Wort/Yeast?

 

[flyangler18]

Is there any good basic explanation of that pitching calc? I thought I was kind of smart but that thing confounds me..

Example, Making an Ale with a 1.056 OG for a 5.5gal Batch says I need 215 Billion cells (ok?), but what I dont get is it says I need 2.33L of starter?

Is that 2L of slurry total, or 2L of Wort/Yeast?

The MrMalty calculator follows the industry rule of thumb of 75 million cells per mL per °Plato for ales. One °Plato x 4 is the approximate equivalent to OG.

So, following some basic calculations:

75,000,000 cells x 20,820 mL (5.5 gallons - simplified for ease of calculation) X 14 = 218 billion cells, close to the recommended 215 billion cells.

The 2L means the total starter size volume, according to those pitching rates. You'll see that a continuously stirred starter will require the smallest volume.

 

[chumprock]

Thanks.. I assumed such but wasn't certain.

I see that a traditional "simple" batch (Growler) needs 2.33L whereas a batch on the stir plate will only need 1L....

Incentive to get my G.D. drill back from my neighbor and finish my stir plate....

 

[Saccharomyces]

Yes the growth rate for a stir plate is 4-5x more than a simple starter and about double that of an O2 oxygenated starter making a 1L starter good enough for most ales.