[bluesman]

I like to prepare starters with DME and water to a S.G.=1.020-1.030.

I use approximately .75lb DME to 1 gallon of water which will make approx 30GU's or 1.030 after boiling for 10 min. This ratio of DME to water seems to give me the best results.

I then chill the starter wort down to the mid 60's and pitch a vial, smack pack or about 2-3 Tbsp slurry and put on a stir plate for a few days. The starter wort is then cold crashed to drop out all of the yeast into a cake on the bottom of the flask or container.

When I'm ready to pitch the yeast into my beer wort, I'll remove the starter from the refrigerator several hours prior to pitching and decant the spent wort and only pitch the yeast cake.

[morticaixavier]

All this talk about starters and cold crashing brings up a question for me. If you are doing a starter for a hefeweizen wouldn't cold crashing and decanting select for the more floculant yeasts? thus causing your hefe to be to clear? (mitout hefe instead of mit?)

[punatic]

 
 I'm no mathmagician or scientist, but you don't need to be to figure out the DME volume and weight issue.
We're still waiting on the cold pitching lag time theory...
Macros, micros and brewpubs are doing it and they have the most to lose if something goes wrong due to increased lag times.

Lobbying to be a moderator perhaps?

[maxieboy]

Lobbying to be a moderator perhaps?

lol, no. It has never crossed my mind.

[tschmidlin]

Alright.!  Some of you are getting close.

A hint:
bulk density vs particle density...

Are you seriously going to pretend that you're trying to teach us something?   Admit it, you neglected to account for the air when you scoop a cup of DME!

I don't know what you mean by "getting close", I said it:

Fair enough, but that cup of DME is not full of 100% DME, it has quite a bit of air.  A cup of DME measured from a bag of powdered DME will weigh about half of that.

Morticai said it:

how tightly packed the cup is.

Sean said it:

Using the density of a solid's constituent particles introduces a lot of error when that solid is granular. The packing fraction will make a huge difference. The variation between sifted and packed flour, for example, is 25%: http://www.cookingforengineers.com/article/63/Wheat-Flour That's why people are always encouraged to measure by mass rather than volume.

Do you have some magical phrase that you are looking for?

[punatic]

I don't know...how about:
As porosity goes to 0, bulk density approaches particle density.

Hey, the boards were a bit slow this morning, so I figured I'd stir it up a bit...   

So BFI is the only one allowed to have fun sometimes?

You're good with 1 cup DME to 4 cups water?

Never mind.

[punatic]

Lobbying to be a moderator perhaps?

lol, no. It has never crossed my mind.

Oh man... you edited out the altruistic stuff. 
No worries, I wasn't offended. 

[tschmidlin]

I don't know...how about:
As porosity goes to 0, bulk density approaches particle density.

  That works.  I don't remember that phrase from any of my classes, but that could be because they were mechanical engineering or biochemistry classes, not civil engineering or materials science or soil or any of a host of things where that would come into play.  It could also be because I wasn't always paying that much attention

Hey, the boards were a bit slow this morning, so I figured I'd stir it up a bit...   

So BFI is the only one allowed to have fun sometimes?

Not at all, it's just not always clear when people are having fun.   That's one of the problems of the forum, and why I try to use emoticons so people know I'm not taking things too seriously .

You're good with 1 cup DME to 4 cups water?

Nope, like I said, 1/2 cup DME to 4 cups of water is a better ratio for a starter IMO.

[jivetyrant]

Ok, so I tossed the original starter and picked up 3 slap packs of Wyeast 1056 American Ale. (propagator packs, not activator packs)  Mr Malty calls for a 3.26 liter starter using 2 of the 3 slap packs (I bought an extra to keep as insurance) and 326g DME, roughly 11.5oz if I did my math correctly.  It recommends 1g DME per 10 ml final volume.  The next problem is that my flask only hold 2000ml, yikes!  Any recommendations for alternative vessels to prep my starter in, or should a 2000ml starter be sufficient?

[Hokerer]

It's not a good idea to try and get the full 2L of starter in a 2L flask.  Since it gets skinnier as it nears the top, you're reducing the surface area through which oxygen gets exchanged and the whole point of a starter is to get plenty of oxygen to the yeast for growth.

For a bigger vessel, lots of folks use a 1 gallon glass juice/cider jug.

[tygo]

Also, if you fill it up that much, even with foam control you're likely to have it blow out of the container.

I used to use a plastic gallon jug for two liter starters.  Best to use one that contained water rather than milk for sanitation purposes.

[a10t2]

3 slap packs of Wyeast 1056 American Ale. (propagator packs, not activator packs)

If you have three Propagators, there's no way you're going to get to your target cell count in a single step. Three Propagators will be ~75 billion cells, and for a 1.104 ale the target would normally be ~350 billion. According to the "intermittent shaking" option on the MrMalty calculator, you'd need an 6.4 L single-stage starter. Or you could do a 1 L first stage and 2 L second stage.

[jivetyrant]

Am I using MrMalty wrong?  I put in my OG or 1.104, type as ale, volume as 5.00 gallons, production date as 2/2/2011 for an 87% viability rate. Liquid yeast, intermittent shaking, default growth factor.  It gives me 348 billion yeast cells needed, 4 slap packs needed without a starter, 2 slap packs needed with a starter, starter volume of 1.91 liters.

Also, I bought a quality $11 gallon glass jug of some really top shelf wine, which was promptly donated to the kitchen sink.  I would imagine that would be sufficient for most of my starter needs!

[Mark G]

The Propagator packs contain only 25 billion cells, while the Activator packs have 100 billion cells. The Mr. Malty calculator works under the assumption that you're starting with Activator packs. And good purchase on the gallon jug. Those are perfect.

[jivetyrant]

Prepped a 1L starter with 3.5oz of DME and pitched all 3 Propagator packs.  It's definitely a lot more active than my last one was!  When I shake it it foams right out the top of it's 2000ml flask!  I'll pitch to a 2L secondary starter when this one slows down, from what has been said that should get me pretty close to the cell count I'm looking for.  If not I have several packets of dry S04 and S05 I can fall back on, I can't imagine I'd have problems mixing the yeast strains.

When its done I plan to decant off nearly all the liquid and then shake it a bit to get the yeast cake back into suspension then pitch that straight to the carboy.  Is that correct?