Newest Threads

Gtrman13 · 11-28-2012, 08:07 PM

I'm about to brew a Maibock with an projected OG of 1.070. I'm relatively new to lagers, and I just want to make sure my yeast preparation is not going to be a problem. Instead of multiple vials of yeast in a smaller starter, I want to pitch a single vial into a 7 liter starter (per mr. malty). I've never even heard of a starter this large, but I'm able to get my stir plate to spin 7 liters in my bottling bucket so I figured I'd give it a shot. Any downside to doing this? Obviously the water I tested the stir plate with doesn't spin too vigoriously, but there is a tiny little vortex in the middle. Anyone try this before? How did it go? Thanks!

**stratslinger** · 11-28-2012, 08:12 PM

Just a thought on an alternate approach: Playing with YeastCalc.com (it allows you to play with steps) it looks like you could also get there in two steps - just do a 1.7L starter, decant, and pitch the slurry into a second 1.7L starter. Might be a little easier to manage than a 7L starter in your bucket.

stpug · 11-28-2012, 08:16 PM

According to yeastcalc you could get really close with a 1 liter starter stepped up to 2 liters if you start with a fresh packet of yeast.

inhousebrew · 11-28-2012, 08:26 PM

I'll second yeast calculator. I just recently discovered that site and find it way more user friendly than Mr. Malty and it allows you to do the steps which I just used for a pilsner I did.

Gtrman13 · 11-28-2012, 08:51 PM

Ah, yes that does sound much easier! Although, I was kinda starting to get a little excited about my giant starter... But I suppose I'll stick with the more sensible approach. Thanks all!

**Golddiggie** · 11-28-2012, 08:54 PM

Quote:

Originally Posted by Gtrman13

Ah, yes that does sound much easier! Although, I was kinda starting to get a little excited about my giant starter... But I suppose I'll stick with the more sensible approach. Thanks all!

I've gone with two, and three, stepped starters to get more cells than you could with a 20L+ starter. Especially when using older packets of yeast (more than a few months old). With either a 2L or 3L flask, you can do two, or three, starter steps for pretty much anything you would brew (in a batch size of up to 10-12 gallons).

**dinnerstick** · 11-29-2012, 06:57 AM

in zainasheff&white's YEAST book they explain pretty well, and show a simple experiment to back up the idea, that as you decrease your pitching rate, you decrease your 'yield factor' (cell count increase per degree plato consumed). practically, that means that as you pitch your pack into larger and larger starter wort volumes, at some point you reach a cutoff where the yield starts to decrease. you still get more yeast out from a larger starter than a smaller one, as there is more sugar and more yeast growth, just that in a huge starter, for each gram of DME you are getting fewer cells in return. in their experiment they pitched 1 pack/vial into different sized starters and measured the growth rates, the optimal results were in the 1-2L range, but from 0.8 to 8 liters were in the same ballpark, and still perfectly acceptable for the homebrewer. of course these rates are calculated for you in yeastcalc.com, as the others have pointed out, play with the numbers and starter sizes on the website and see what works for you! and these experiments were done with a fresh 100 billion cells, whereas shipped packs of course have significant viability dropoff; so if you're really pitching 10 billion cells into 7 L, your yield factor may be really on the downward slope of the curve, and you will really benefit from a smaller step-up. thanks for the excuse to go back and re-read that section of the book.

WoodlandBrew · 11-30-2012, 01:53 PM

Call me crazy, but for 5 gallons of a 1.070 lager a single 7 litter starter sounds small. I would think you would need about 500 billion cells if my math is right. That's a "growth factor" of 4, or a yield of 5 times the initial cell count. It would take three sequential 3 litter starters to get there according to yeast calc.

Might I propose an alternative:
Pitch 100 billion cells into 1 gallon of your wort on brew day. On the following day add the remainder of the wort.

There are two reasons why it should be one gallon. First, Mr. Malty tells us that 100 billion cells in 1 gallon of 1.070 wort is the correct pitch rate for a lager. Secound, cell growth is roughly proportional to the amount of sugar, so pitching into one gallon of your wort will produce about 500 billion cells. And bonus, there is no wasted DME or time spent on a starter.

**Herky21** · 11-30-2012, 02:02 PM

Quote:

Originally Posted by WoodlandBrew

Call me crazy, but for 5 gallons of a 1.070 lager a single 7 litter starter sounds small. I would think you would need about 500 billion cells if my math is right. That's a "growth factor" of 4, or a yield of 5 times the initial cell count. It would take three sequential 3 litter starters to get there according to yeast calc.

Might I propose an alternative:
Pitch 100 billion cells into 1 gallon of your wort on brew day. On the following day add the remainder of the wort.

Cell growth is roughly proportional to the amount of sugar, so pitching into one gallon of your wort will produce about 500 billion cells. And bonus, there is no wasted DME or time spent on a starter.

Yes, but for many brewers this raises the concern of where to put the infection-risk wort that isn't fermenting for a day. Another plastic fermenter is cheap, sure, but I think there are some other added risk factors you would be getting into by using this method.

That being said, it's also kind of a cool idea. It isn't much different than say, fermenting a large batch of belgian beer and adding sugar after a few ays of primary. Sure, the purposes are different, but the risks of opening the bucket and sanitation are nearly the same, minus the risk for infecting the 4ish gallons of wort for your proposed method.

progmac · 11-30-2012, 02:10 PM

Quote:

Originally Posted by WoodlandBrew

Might I propose an alternative:
Pitch 100 billion cells into 1 gallon of your wort on brew day. On the following day add the remainder of the wort..

What a practical and good idea!