Beer Forum

Getting ready to brew 11G of a 1.050 wort.

Per the Jamil, Mr. Malty calculator, I need a 4.6L starter based upon 2 smack packs, my viability and method of intermittent shaking.

I only have a 5L flask. Instead of trying to work with doing a 4.6L starter in a 5L flask, can I start out with 2L, decant and add an additional 2.6L? Or would my second step need to be of greater volume?

thats a weird question because ive never thought of doing it that way, but it seems like you would be fine the way you described because the total volume is correct. you might lose a little in the supernatant, but i cant imagine it would be a huge percentage.

If you decant warm you will lose a good amount of healthy, active yeast suspended in the liquid; to prevent this you would want to refrigerate your starter, let the yeast drop out, then decant, then step your starter back up. I have heard Doc and Jamil talk about doing this on some of the shows.

I thought I had heard about it being talked about before..... I would of corse chill before decanting. Guess I'll see how it goes and report back.

I don't think that's going to work as well as one 4.6L. I just listened to the yeast show with the Whites and they said that the yeast figure out how many times to reproduce based on how much sugar each cell has to itself, or at least that's what I gathered. On the show, they gave an example where doubling the start size caused the growth factor to go from 1.1 to 2.8. Applied to your example, you would get 200B x 1.1 x 1.1 = 242B, vs 200B x 2.8 = 560B. Those probably aren't the exact growth factors in your case, but you get the idea. So if you cut the starter size in half, I think you're going to get a lot fewer cells than you're expecting.

I'm butting up against the same issue, particularly with some lagers coming up. This is how I'm dealing with it...



Assume I'm making an 11 gallon batch of 1.050 lager and I have 1 vial of White Labs yeast. Mr. Malty tells me I need:

Cells needed = 771 billion

To get 771 billion cells, Mr. Malty recommends pitching 2 vials into a 6.8L stirplate starter(SPS), or 3 vials into a 4L SPS, or 4 vials into a 2.75L SPS. My largest flask is 4L, so I'm limited to about 3-3.5L of starter. So, the only feasible option is pitching 4 vials into 2.75L. I only have 1 vial of yeast, so that doesn't help me BUT it does tell me that if I pitch 400 billion cells into a 2.75L starter, I will get my desired cell count. So, now I know I need to step my 1 vial up to 4 vials/400 billion cells.

To determine how to get 400 billion cells you just need to enter a theoretical batch that requires 400 billion cells. For example, Lager/1.050/5.7gal. It doesn't matter what you enter, the starter will be the same if the cells required is the same. Try Ale/1.090/6.6gal, the starter is identical. It recommends either 1 vials into a 3.7L SPS, or 2 vials into a 1.5L SPS.

The 3.7L volume is still a little too much for my flask, so I go through the same exercise again. I want to step up my 1 vial to 2 vials/200 billions cells. I enter Lager/1.050/2.9gal. Mr. Malty tells me I can get 200 billion cells with 1 vial in a 1L SPS.

So, this is what I do:

1.) Pitch 1 vial into 1 L for a yield of ~200 billion cells.
2.) Chill, decant.
3.) Add 1.5L of sterile wort to decanted yeast, yielding ~400 billion cells.
4.) Chill, decant.
5.) Add 2.75L of sterile wort to decanted yeast, yielding ~770 billion cells.
6.) Chill, decant.
7.) Pitch to 11 gallons of 1.050 wort.

Getting ready to brew 11G of a 1.050 wort.

Per the Jamil, Mr. Malty calculator, I need a 4.6L starter based upon 2 smack packs, my viability and method of intermittent shaking.

I only have a 5L flask. Instead of trying to work with doing a 4.6L starter in a 5L flask, can I start out with 2L, decant and add an additional 2.6L? Or would my second step need to be of greater volume?

I'm assuming you need ~385 billion cells. Based on your numbers you seem to have 53% viability.

Your first starter will have almost 100% viability, so go back and calculate your starter size assuming 100% viability.

It should tell you to pitch 2 vials into 2L, therefore you need to step up your two 53% viability smack packs to 200 billion cells. Enter Ale/1.050/5.7gal. It should tell you to pitch your two 53% smack packs into 1L of starter to yield 200 billion cells. So, your step up schedule is:

1.) Pitch your two smack packs (53% viability) into 1L of starter, yielding ~200 billion cells (with near 100% viability)
2.) Chill, decant
3.) Add 2L of starter wort to your decanted yeast, yielding ~385 billion cells.
4.) Chill, decant
5.) Pitch to 11 gallons of 1.050 wort.

Two questions on this one how long do you let each step go for before chilling?, and how long do you chill for before decanting and steping up?

I let each step go 18-24 hours and chill overnight before decanting. It probably only takes a few hours to get most of the yeast out of suspension when you chill it, but I let it go overnight because I'm usually pulling it off the stirplate after work. Then I decant the next night.