2 Step Starter

[Bullhog]

Hey everyone,

I’m doing a two-step yeast starter and wanted to double-check my thinking. Step one was 1.25L with 136g of DME for OF of 1.040. For step two, my calculator says I need 2.5L with 273g of DME to get to my target cell count.

I’m not planning to decant after step one — just going to pitch the full 1.25L into the second step. So here’s my question:

Should I make 2.5L of wort with the 273g of DME and add that to the existing 1.25L (giving me 3.75L total)? Or should I just dissolve the 273g into 1.25L of water so the final volume is 2.5L?

I get that adding the first 1.25L will dilute the gravity if I make a full 2.5L of wort, but I’m not sure if the yeast calculator is expecting the 2.5L to be total volume, or just the amount of new wort. Maybe I'm overthinking and either way works....

Appreciate any insight — thanks!

 

[Deadalus]

Rule of thumb is that 10 ml to 1 gram will provide ~ a 1.040 wort. Both your steps would be approaching that if prepared separately, which is what I am pretty sure is what you are being asked to do. You would also have a higher gravity than 1.040 if you were to dissolve the 273 g into the first step and then topping it off since there is still mass left from the fermented first step. You also would have no option to boil the DME that way.

 

[BongoYodeler]

I use Propper Starter rather than dme.

In your case I would make 2.5L of wort with the 273g of DME, and add that to the existing 1.25L, giving 3.75L total. (Or whatever your calculator is suggesting).

Make sure you have a large enough flask to accommodate the 3.75L plus krausen. I'm in the middle of making a 2-step starter, and even though I cold crashed and poured off half the liquid after step 1, I still had a Mount Vesuvius level volcano erupt all over the counter while step 2 was spinning. I ended up adding a few drops of FermCap which took care of the krausen. My mistake for not adding it before the eruption.

 

[Bullhog]

Rule of thumb is that 10 ml to 1 gram will provide ~ a 1.040 wort. Both your steps would be approaching that if prepared separately, which is what I am pretty sure is what you are being asked to do. You would also have a higher gravity than 1.040 if you were to dissolve the 273 g into the first step and then topping it off since there is still mass left from the fermented first step. You also would have no option to boil the DME that way.

I should clarify that I would utilize a boil to make the second step's wort. So I'm really just debating whether to make 2.5L(1.040) or 1.25L(1.080) wort for the second step. The starter calculator is telling me to use a 2.5L starter volume for the second step, so I am not sure if I am supposed to end up with 3.75L or 2.5L.

I'm using Homebrew Dad's calculator. At first, I assumed that I would end up with 3.75L, but the bottom of the calculator tells you to pitch the volume of the second step (in this case 2.5L, not 3.75L), so this is where I started questioning the method.

 

[BongoYodeler]

You should finish with 3.75L. Wouldn't make a lot of sense to make two 1.25L starters.

In my case I made a 1L 1.040 starter as step-1, cold crashed, and decanted half. I then made an additional 2L 1.040 starter as step-2, (for a total of 3L).

 

[day_trippr]

5 liter e-flask ftw

Cheers!

 

[Deadalus]

Ok I see how you would boil it using the 1.25 liter amount. I don't see detailed instructions at the link but may be missing them. I do understand the uncertainty given the final pitch amount calculated.

I step my yeast starters up in 4-10x volume increases using the 10:1 rule, which us about 1.040. If I think the yeast is old or weak I occasionally use a 1.020 starter and then step up to 1.040. I don't decant while stepping up. However, I do use overbuilt starters where I have stored about 200ml. These are decanted as they have been sitting in the fridge. For example, if I needed a 4l starter for a lager, I would decant the stored yeast into 800 ml starter then step up with 3200ml more. That I would let finish fermenting, then chill and decant as that's a lot of starter to pitch. A lager yeast fermented at 70F is going to add a lot of off flavor, so decanting is good. Now a calculator could get a finer calculation but there's uncertainty based on the initial estimates of viability.

If you ballpark the specific gravities of both a 75% attenuated wort + 1.080 at 1.25 g and the full 2.5 addition, I don't see much sg difference on my quick back of the napkin estimate. The first is about 1.045 and the other is about 1.030 if I did it right.

 

[Climb]

@Bullhog - Why do you not want to decant between steps? You should decant after the second step and before pitching.

 

[Bullhog]

@Bullhog - Why do you not want to decant between steps? You should decant after the second step and before pitching.

Decanting takes too much time, days to weeks to get it cleared. Decanting or not decanting is fine, but if I decant and I’m in a hurry I have to assume a higher amount of loss in the final cell count. I’ll decant after the second step, but decanting twice is just too much loss or too much time. Trying to be more efficient.

 

[hottpeper13]

I don't own a 5 L flask and if I need more then a 1.5 L starter I just make a small beer(3%-4%) 5 gal batch. I then decant into a keg and drink it. I repitch 2-4 times, and saves a ton of money.