[ckpash88]

Hello,

So digging through the posts i cant find a answer to my question.

So I making a lager with a gravity of 1.050 and i was on mr malty and it told me that i need a starter of 7.86 litres or 2 gallons. That seems a little big isnt it?
what should the size be?

Next question if i want to make a gallon starter do i make a gallon of wort at a gravity of about 1.040 and add one wyeast activator pack and let it forment for about 24 hours then add that to my wort?
Or how do I do it?

I need a idiot proof answer bc i am trying to figure out this yeast starter thing lol

[denny]

I'd believe what mrmalty tells you.  For a starter that big, you want to make it well in advance so you can decant the spent wort.  You don't want 2 gal. of that stuff going into your beer.

[ckpash88]

So would I make 2 gallons of wort and add the yeast packet then let it ferment out then decant the liquid then add it to the wort. Or do I need to make the starter in steps?

[tygo]

Yeah, make the starter, let it ferment out, and then refrigerate it for 24-48 hours to get all of the yeast to floc and settle.  Then decant the starter beer and pitch only the yeast.

You can also reduce the size of the necessary starter by using "intermittent shaking" rather than a simple starter.  Just shake up / vigorously swirl the starter as often as you can while it's fermenting.  That will blow off some of the CO2 and hopefully pull in some additional oxygen.

[ckpash88]

A two gallon sounds big is that right?
I am looking at site and they say anything from 1000ml is good to a gallon I am lost.
So what I see is according to mr malty I need to add 2 pounds of dme to 2 gallons of water to make a starter the right size for my 5 gallon 1.050 og lager.

I am lost will someone help lol

[a10t2]

Have you checked out the FAQ? http://www.mrmalty.com/starter_faq.php

Like tygo said, you can reduce the size of the starter by introducing oxygen, even if it's just by shaking.

[euge]

Can't one even improve that more with a stir-plate? According to Mr Malty you only need 1.22 litres on a stir-plate for a 1.050 5.25 gallon lager.

[tygo]

A two gallon sounds big is that right?
I am looking at site and they say anything from 1000ml is good to a gallon I am lost.
So what I see is according to mr malty I need to add 2 pounds of dme to 2 gallons of water to make a starter the right size for my 5 gallon 1.050 og lager.

I am lost will someone help lol

Yeah, 2 gallons is big.  It'll do the job but that's a lot of starter to deal with and a lot of DME to go through. 

According to mrmalty for five gallons of a 1.050 lager and selecting "intermittent shaking" from the drop  down box you need a starter of about 4.25 qts.  Now that's assuming 100% viability, which is pretty much impossible if you're pitching from a smack pack. 

So what I would do is make a 1 qt starter with 3.5 oz of DME, let it ferment out, crash it in the fridge for a day or two, decant it off leaving just the yeast, and then pitch another 4 qts of starter wort (made with about 13 - 14 oz of DME).  Ferment, crash, decant, and pitch.

[tygo]

Can't one even improve that more with a stir-plate? According to Mr Malty you only need 1.22 litres on a stir-plate for a 1.050 5.25 gallon lager.

Yeah, a stir plate would be ideal.  I'm assuming he doesn't have one.  One of these days I'm going to get around to picking one up myself.  It's on my wishlist.

[nateo]

One thing I'm not sure about mrmalty is whether the calculator factors in different growth curves for different inoculation rates. I think doing stepped starters, like doing 2L > 4L would result in about the same growth as one 8L starter, but I'll have to doublecheck my math when I'm not at work.

[tygo]

One thing I'm not sure about mrmalty is whether the calculator factors in different growth curves for different inoculation rates. I think doing stepped starters, like doing 2L > 4L would result in about the same growth as one 8L starter, but I'll have to doublecheck my math when I'm not at work.

I think it does but it bases that inoculation rate on the % viability of (I'm assuming) the 100B cells you'd find in a fully viable smack pack.  So theoretically you could play around with the % to get proper inoculation rate for a stepped starter.  Since I'm just estimating the amount of cells I'm pitching anyway I take the laz...er, pragmatic approach.  If the calculator is indicating a starter greater than 4L I do an initial step, somewhere in the 0.5 - 2L range depending on how much I think I need to achieve.

I'm certain there is a more scientific way to approach this using the calculator.

[a10t2]

I'm certain there is a more scientific way to approach this using the calculator.

Yup.

http://seanterrill.com/2010/03/08/two-stage-starter-calculations/

[nateo]

The Sean Terrill site is pretty cool. Probably my favorite thing about the internet is you can almost instantly find the answers to any "I wonder if. . ." questions. I haven't tried to trick MrMalty yet, but I plan to look into that.

From my pen-and-paper calculations based on the chart in "Yeast", I think doing one smack pack with 100b cells, a 2L > 4L stepped starter would yield 430b cells, while 100b cells in an 8L starter would yield 400b total cells. So you'll get marginally more yeast, and use 2L less wort, but have a little bit more hassle. Of course, I was never a great math student, so I could be wrong.

[a10t2]

The Sean Terrill site is pretty cool.

Thanks! I haven't been able to put nearly as much time into it lately as I'd like, but there's some good stuff in the pipeline.

[tygo]

I'm certain there is a more scientific way to approach this using the calculator.

Yup.

http://seanterrill.com/2010/03/08/two-stage-starter-calculations/

Nice.  That comment was actually bait for you since I had a vague memory of you posting something about this in the past.   

Here's a question though.  I applied those instructions to the OP's situation.  For this simulation I assumed a viability of 70% just to have a number.  I put in a volume of 4.98 gallons and an OG of 1.030 to get to 2 liters of starter required for the first step which calculates 213B cells.  I then put 213 into the viability field and set the OG to 1.050 and the volume to five gallons.  Also set to Lager and Intermittent Shaking.

The result is that for the second step it's telling me I would need 1.48L of starter for the second step to achieve 350B cells.  That's obviously not doubling the volume for the second step.  I've tried a couple of other scenarios and got similar results.  What am I doing wrong?