Questions on making a yeast starter

I'm preparing to brew my first batch. It's an Oatmeal Stout with an OG of 1.064-1.070 using Wyeast #1084 Irish Ale Liquid yeast with a production date of 8/19/09. Here's the full recipe (partial mash):

6 lbs. Pale malt extract
1.5 lbs Gambrinus pale ale malt
.5 lbs Gambrinus white wheat malt
.5 lbs Breiss caramel 120 L malt
.5 lbs. Breiss chocolate malt
.5 lbs Breiss roasted barley
.25 lbs Breiss black malt
1 lb Oat flakes
.5 oz. American Summit hop pellets - bittering
1 oz. New Zealand Hallertaur whole hops - flavor
Wyeast #1084 Irish Ale
1/2 tsp. Irish Moss

I used Mr. Malty's yeast calc and here is the result:



I've read several threads on making starters as well as the section in John Palmer's book and on Mr. Malty's site. As in most things related to brewing, there are varying opinions on the proper technique. I'd like to ask yours.

1) Should I just use 2/3 cup of the liquid pale malt extract that came with the Oatmeal Stout kit in the yeast starter, or should I get additional LME for it? John Palmer says it's a good idea to use the same LME for the yeast starter that you will use for the wort.

2) Is it really necessary to use 2 starter packs of yeast in a 2 liter solution for this beer? If so, how much LME do I need to use? (I'm unclear on how to calculate that).

3) If I do use a 2 liter starter, should I put it in the fridge the night before brewing to allow the yeast to flocculate out of solution and then decant the wort so that I pitch only the slurry into the fermenter?

4) What is the best/easiest way to decant the wort from the yeast starter?

5) How long should I allow the yeast starter to sit? I've seen recommendations from 18 - 36 hours.

1- you can use it, but I think its easier to use DME, not LME. If you buy a 5lb bag, you can store it for making starters

2 - no. A starter is meant to propogate yeast from 1 pack. If you use 2 packs, just pitch them directly.

3 - It won't hurt.

4 - Pour gently. try not to disturb or pour out any yeast.

5 - I've made a starter a week ahead and a day ahead. Less than 24 hours probably won't get much growth.

Edcculus said:

2 - no. A starter is meant to propogate yeast from 1 pack. If you use 2 packs, just pitch them directly.

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That's what I thought, but if you look at the screenshot I posted above, Mr. Malty says to use 2 packs of the liquid yeast in a 2 liter solution if I am making a starter.

Most of the other directions I've read suggest 2 quarts of water, 1 yeast package and something like 2/3 cup of DME.

switters said:

. . . if you look at the screenshot I posted above, Mr. Malty says to use 2 packs of the liquid yeast in a 2 liter solution if I am making a starter.

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And that's what you should do. Think of it as stepping up from a 1qt starter, except you already have the higher count from using two packs. If you use your liquid extract use about 1/2lb with two quarts of water and add both packs of yeast. The end growth is directly proportional to the amount of cell you start with provided you supply them with the correct amount of fermentable material. (Shoot for a OG of 1.030 to 1.040 in your starter.)


Edit:
But I would do as Edcculus suggested and buy some DME. With that you'd use about 6 1/2 oz with the 2 quarts of water and 2 packs of yeast.

You can adjust the growth factor. Slide that bar up until its saying 1 pack in the starter. You will need a 5 liter starter. $12 is a bit much to spend on yeast IMO.

So one option is to make a 2 quart starter and the other is to do a 5 liter starter? Why such a large discrepancy? I can accept that there is more than one way to get a good result, but it sure is confusing for a newbie trying to figure out WHY things are done the way they are.

In any case, I'm assuming if I make a 5 liter starter I should decant the wort and just use the slurry. Also, how do I calculate how much DME I would need for 5 liters of starter?

I guess less water and less DME is needed with a 2 quart starter because we're using 2 packs of yeast?

Yea, sorry to confuse. Maybe AnOldUr meant to say 2liters? Thats what the calculator says if you keep the growth factor low (smaller starter, more packs). Yes, if you do a 5L starter, you will want to decant.

I follow the method Jamil outlines in the Yeast Pitching Rates
page.

Use a 10 to 1 ratio. Add 1 gram of DME for every 10 ml of final volume. (If you're making a 2 liter of starter add 200 grams of DME to the flask, then fill the flask with water until you have 2 liters total.)

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That means for a 5L starter(5000mL), you will use 500g of DME.

Thanks a lot for sticking with me on this!

I went back to the Mr. Malty calculator and noticed the drop-down menu for the type of starter. When I switched to "Intermittent Shaking" instead of "Simple Starter", and raised the growth factor, I am now getting 1 pack of yeast with 2.74 liters for a 1.067 OG. That sounds like a good compromise. Using the 10 to 1 liquor to DME ratio I would put 274 grams (.6 lbs) of DME in a container and add water until it gets to 2.74 liters.

Mr. Malty suggests pitching at high krausen between 12-18 hours after making the starter. However, he also says:

Of course, if you have a large starter volume in relation to your batch of beer or a starter that was continuously aerated, then you probably don’t want to pitch the entire starter into your wort. Adding a large starter or a heavily oxidized starter to your wort can alter the flavor of the finished beer.

If you’re going to pitch only the yeast from the starter, make sure the starter attenuates fully before decanting the spent wort. The yeast rebuild their glycogen reserve at the end of fermentation and it is this glycogen that they use when preparing to ferment a new batch of beer. Separating the spent wort from the yeast too early also selectively discards the less flocculent, higher attenuating individuals in your yeast population. You may end up with a pitch of yeast that won’t attenuate the beer fully. Allow the fermentation to go complete cycle, chill, decant the beer and pitch just the yeast.

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Is 2.74 liters considered a large starter volume? If so, how long would it take to attenuate fully before I decant the spent wort?

Now I just have to figure out what kind of container I can use to make the starter. Most juice bottles aren't that big. Any ideas?

I haven't done experiments, but I don't think its a huge deal when you pitch. For a 2 liter starter, I usually like to decant.

As for a vessel, do you have any growlers, gallon jugs or even a pitcher? If worse comes to worse and you cant find something big enough for 2.74 liters, 2 liters should suffice. Thats a whole lot better than nothing.

Anything wrong with using a 2L soda bottle, as long as it's well-cleaned, like soaked in oxy? Or are the bumps on the bottom a bad thing (breaking up the yeast cake)? I'm brewing with my first liquid tomorrow, and have a vial of WLP810 San Francisco Lager yeast in the fridge to pitch. (Sorry to piggyback this on OP's thread)

Twitters, you don't mention when you wish to brew, but I am guessing this weekend. A couple thoughts.

I was going to say look at the drop down and change to intermittent shaking but I see you found that. Try to give it a good shake/swirl once an hour if possible.

Consider investing in a stir plate. Much better growth as you can see the stir plate gets you down to about 1.8 liters required. If you had a 2 liter flask and stir plate you could get away with say a 1.5-1.6 liter starter and just be a tad low on the pitch, not enough to really matter.

If you start the process several days in advance you can step up the starter. Instead of having to do one large starter like 2.8 liters,, you start off with say a 1.5 liter starter. You let it complete and decant off the beer. Now you can either pitch the whole slurry into another 1.5 liter starter, or I would just use about 10-20% of the slurry and pitch that into 1.5 liters for another starter. You'll get more yeast that way then if you pitch the whole first starter into another one. When the second starter is done you pitch both into your beer.

If you do make a 3 liter-ish starter you are probably better off decanting. It's not an absolute, but it is starting to become a large enough volume that it could affect the beer flavor.

Thanks, Zen_Brew. I did read a bit about stepping up starters, and it's likely I won't make the beer until next weekend because I don't have all of the equipment yet (I will hopefully pick it up today if the LHBS has everything I need).

So, using the method you suggest, I would use 1 pack of yeast with 1.5 liters and 150 grams of DME? How long on average would the attenuation take to complete with that?

I then decant the wort and (scoop out with a sterilized spoon?) 10-20% of that slurry and pitch into another 1.5 liters / 150 grams of DME for another starter? What do I do with the other 80% of slurry? Put it in the refrigerator?

At the end of that process, I pitch both slurries into the wort?

That sounds right, except for the decanting. When the starter has completed, stick it in the fridge. After a while, the yeast will collect at the bottom. Pour off the liquid while trying to keep the yeast. Don't pour off all of the liquid, just a lot of it. You will then have a slurry of mostly yeast. Pour some of that into a new starter.

Approximately how long would it take for the starter to complete? Mr. Malty says it will reach maximum cell density within 12-18 hours. Is that how long you're thinking?

Yea, go with that. Jamil knows a lot more about brewing than I do

First off I noticed I called you Twitters in my last post. My apologies Switters.

Use the Method Edcculus said where you leave some of the liquid after you decant. Swirl it up to get the yeast in suspension and then just pour off the portion you want to use for the next starter. Put the rest back in the fridge. Try to take the yeast out of the fridge 3-4 hours before you pitch it to let it slowly come up to room temp.

12-18 hours is how long till you have hit full yeast colony growth in the starter. This is when you can pitch at peak activity if you wish. If you are waiting for the whole thing to ferment out to chill then decant I would say maybe 72 hours. Only the yeast know for sure. If you were in a time pinch you could try a bit earlier but I'd say 48 hours as an absolute minimum to let most of it ferment out.

I just finished fermenting an oatmeal stout with an OG of 1.071. My FG settled at 1.028 (should have been under 1.020), so this will be a sweet batch.

My thoughts on causes:

1. Didn't pitch enough yeast (actually, the OG was the result of surprisingly good AG efficiency, so I wasn't prepared to pitch enough yeast). I trust Jamil's calculator.

2. Didn't aerate enough. Higher gravity beers need lots of oxygen to make the yeast happy.

3. There's a remote possibility that I had a lot of unfermentables (i.e. mash temp too high), but this is unlikely as I have calibrated my thermometers and I hit my temps.

So for you:

1. Pitch the amount Jamil recommends.

2. Shake the bejeezus out of the fermentor to get it aerated.

3. Doesn't apply since you're doing extract.

Good luck!

Thanks for the tips, RunBikeBrew. That's very helpful. The last step actually does apply somewhat because I'm doing a partial mash. Good things to think about.