Do I Need a Stir-Plate and a 2-Liter Flask?

A member passed this article on to me, more or less stating I needed a stir plate and a 2 liter starter to arrive at the 200 billion cell count magic number. Some of it strikes me as dubious, or overly academic, but I'm curious to hear your take. Should I go out and buy a 2 liter flask and accompanying stir plate? Or perhaps I should say, are those accouterments necessary for an ideal fermentation?

As it stands, I have a 1-liter flask w/ airlock, and according to the chart in that article, I'm getting no where near the yeast numbers I should have...

You don't need a stirplate or a flask. It helps but you don't need it.

I bought a 2 L glass milk jug from the local grocery store for a couple bucks. A plug and airlock fits in the mouth perfectly.

As for the stirplate I just pick the glass bottle up and give it a good swirl everytime I walk past it. I'm in the market for a inexpensive stirplate though.

You MUST have a TWO liter flask, and a stir plate in order to brew, even acceptable beer!!

Or you could just mix your dry yeast with a little water, and dump it in. Your call.


Seriously, if I'm brewing a pale ale, or an IPA, or brown ale, something similar, I do not see the point of a liquid yeast. It costs way more, does not make the beer any better, and does not begin to work as fast as the dry unless you make a starter, which is one more area where your beer can collect off flavors.

Maybe this does not address the question you were asking..sorry..

Another note on the 200 billion cell count magic number....

The cell count needed depends on the OG....

Ales & Lagers
The general consensus on pitching rates is that you want to pitch around 1 million cells of viable yeast, for every milliliter of wort, for every degree plato. A little less for an ale, a little more for a lager. George Fix states about 1.5 million for a lager and 0.75 million for an ale in his book, An Analysis of Brewing Techniques. Other literature cites a slightly higher amount. I'm going with Fix's numbers and that is what the pitching calculator uses.

The Math
If you're curious, here is the simple math to calculate the number of cells needed. For an ale, you want to pitch around 0.75 million cells of viable yeast (0.75 million for an ale, 1.5 million for a lager), for every milliliter of wort, for every degree plato.

(0.75 million) X (milliliters of wort) X (degrees Plato of the wort)

There is about 3785 milliliters in a gallon. There are about 20,000 milliliters in 5.25 gallons.
A degree Plato is about 1.004 of original gravity. Just divide the OG by 4 to get Plato (e.g., 1.048 is 12 degrees Plato).
So, for a 1.048 wort pitching into 5.25 gallons you need about 180 billion cells.

(750,000) X (20,000) X (12) = 180,000,000,000

As an easy to remember rough estimate, you need about 15 billion cells for each degree Plato or about 4 billion cells for each point of OG when pitching into a little over 5 gallons of wort. If you want a quick way of doing a back of the envelope estimate, that is really close to 0.75 billion cells for each point of gravity per gallon of wort. Double that to 1.5 billion for a lager.

Copied from Proper Yeast Pitching Rates

Sean said:

Seriously, if I'm brewing a pale ale, or an IPA, or brown ale, something similar, I do not see the point of a liquid yeast.

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I agree I usually only use liquid yeast for Belgian styles and hefs.

I tend to like liquid for the variety, but also because I start starters from washed yeast, which is liquid for all intents and purposes. I have a 1-liter flask with an airlock, and this is my first go with a starter in it. This thing has been chugging away for 48 hours now, and the airlock is still bubbling constantly. It's very possible I only ended up with 60 billion cells via this method (as per that article), but so many people do it this way...how can it be wrong?

And you know, that said, on my first brew (which was a 1.060 oatmeal stout), I pitched the Wyeast activator pack and nothing else, as I didn't know any better. The airlock started bubbling within 8 hours, and chugged away for about 4 days. When I bottled it, I had a nice, healthy, thick layer of flocculated yeast. Preliminary samplings (from the OG tube) tell me it's going to be a pretty decent brew.

What I'm saying is, I'll be the first to lay down $200 on a stir plate and a 2 liter flask if I know I'm going to see a marked improvement. But will I?

I bought a 2L flask online somewhere and it is (so far) unusuable on a stirplate because the bottom is concave; the stirbar will not stay centered. Haven't tried all my stirbars on it yet, though.

Since the other replies have covered the brewing related answers let me take a different tack.

A economist describes a need as "a want backed up be economic means". Do you want a flask and stir plate? Do you have the money?

camiller said:

Since the other replies have covered the brewing related answers let me take a different tack.

A economist describes a need as "a want backed up be economic means". Do you want a flask and stir plate? Do you have the money?

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I only want it if I need it, from a biological standpoint. I have the money, but am not in the habit of spending on things I don't need. A 2-liter flask and stir-plate are nifty, but not something I'm clamoring to the LHBS to get.

But I'm still not sold one way or other. If someone (other than the author of that article) tells me truthfully and irrevocably that a stir plate and 2-liter starter are mandatory for satisfactory pitching rates, then I'll go out tomorrow and buy one. I'm talking personal feedback, as in "I was tooling around with a 1 liter w/ airlock, and I did okay, but man, the beer improved noticeably when I got a stir plate and 2-liter!"

So far, the only arguments I've heard favoring the stir plate have been academic, ie: "Our PhD certified calculations and instruments tell us that 200 billion cells is the required number for a decent brew, and the only way to arrive at that is via a stir plate and 2-liter starter."

A couple of points

0. The arguments and techniques you're dismissing as overly academic are supported by research, experimentation and evidence. That your preference is to dismiss these in favour of anecdotal evidence is odd. In the world of anecdote, you'll hear a different argument from each person until you hear the one you want. Of course people can make good beer without a stirplate and flask. The majority of people who don't have a stirplate probably don't see the point of one. The question you should ask is "do you have a stir plate? and if yes, would you go back to the way you made starters before?" In my anecdotal case, yes I own one, and no I'd never go back. I pitch 1L of starter into 10gallons of wort and I have beer in under 48hrs. Never saw that performance before the stir plate

1. There is no benefit to a stir plate if you're putting an airlock on your starter flask. The whole point of the stirring is to have continuous aeration of the wort and that is rendered moot if you're keeping air out of the flask.

2. Shaking a flask with an airlock every time you walk past is pointless as there is no air in there to aerate. If you're going to go the shaking route, just put a cap of tinfoil over the mouth to allow gas exchange. A foam plug works as well if you can find one.

3. If you make a starter with a flask/stir plate setup using a loose cap of tinfoil to prevent nasties entering, you'll have profoundly better results than with either of the methods described above. Yeast fermenting aerobically can produce all the cellwall components they need readily (requires oxygen) and can build up supplies for the future. I'd guess this makes it a bit less necessary to fully aerate your wort, same as if you're using dry yeast.

4. Yeast fermenting aerobically can do more with less as the sugars are fully converted to CO2 and H2O rather than CO2, H2O and ethanol. The result is you can use a smaller starter to hit your target cell count .5L of wort as opposed to 2L.


Cheers

i too try to avoid spending money on things for which i will not get a good return on investment (i can't truthfully say that i NEED any of my beer stuff).

forgive me if it's already been mentioned but it's worth poking around this site and others looking at homemade stir plates. they're pretty easy to make, cheap, and don't require many if any special tools.

Just to make someone cry a tear, last summer we visited friends upstate and visited the local town. We walked into a thrift shop where they had tables full of scientific glassware for sale for practically nothing. I picked up a 1,000 ml beaker and a 250 ml flask for about $4.

If I would have known then what I know now............

A 1000 mL flask is better than no flask/starter, but a vessel that is at least 2000 mL is the way to go. The higher count will make your beer taste better and there just isn't enough room in the 1000 mL to get you near the optimum. Of course, the flask isn't necessary, but you would be happy with a larger vessel to build up the yeast count a bit more. The flask is just convenient because you can put it right on your burner and boil the starter wort and sanitize the flask all in one fell swoop.

I do not use a stir plate. I also swirl my flask whenever I walk past it. I also don't use an airlock, just a sanitized piece of foil crimped over the top.

Joe Camel said:

The whole point of the stirring is to have continuous aeration of the wort and that is rendered moot if you're keeping air out of the flask.

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You want to aerate the starter at first, but after that the stir plate/swirling of your starter vessel is to keep the yeast in suspension so that they can eat fermentables and reproduce.

I was asking almost identical questions just a few days ago! I think you can find almost all of the answers you need here:

Fourteen Essential Questions About Yeast Starters

and here:

Proper Yeast Pitching Rates

Both sites offer a ton of plain-english answers to the most common questions around including stir plates and pitching rates. I'll spare you the "if you just did a search" routine because I can tell you need answers, not a lecture. Someone more easily annoyed than myself can lecture you at will.

I sincerely hope that info helps.

-Tripod

Joe Camel said:

1. There is no benefit to a stir plate if you're putting an airlock on your starter flask. The whole point of the stirring is to have continuous aeration of the wort and that is rendered moot if you're keeping air out of the flask.

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I think this is an overstatement.

* There is a benefit to a stirplate if you have an airlock: constant suspension of yeast

* an airlock does no more to restrict airflow than any other cover (foil), the tiny bit of backpressure required to push the bubble notwithstanding).

* I would argue that constant aeration is not the whole point; it is one part of the stirplate advantage. Again, suspension of yeast.

* keeping air out of the flask would be significant only if atmospheric oxygen in the flask were depleted by the yeast and they needed more.

Having said all that: I use a stirplate and find it very helpful for building up starters from slanted/plated cultures.