Mr malty's surprising starter prediction

Threw in some figures in Mr Malty's yeast starter app.
I'm going to be brewing up a 1.067/ 6gal porter on Wednesday.
As I type this, I have 1.4L of yeast starter in front of me, with the plan to propagate a second step/batch of starter tomorrow.

My plan was to over propagate tomorrow so I have some yeast left over to decant for a future brew.
However, seeing the Mr. Malty calcuations, it seems its predicting I should be pitching a whopping 2.5L starter!

After doing some research, it seems a lot of brewers make starters to 1.040 regardless of the calc. OG of the brew (excluding extreme ABV's).
So, by the time I've done a 2-step by tomorrow, I'm going to have nothing left to save for a future brew. Thoughts? Should I stick with maybe just doing close to 2L of starter?

Cheers guys :fro:

My thought is if you're going to the trouble of making a starter might as well do it right and pitch the correct amount of yeast. You could always wash the yeast when this batch is done if you want to save on buying new.

A 7% ABV beer is not the ideal beer to save yeast from. I mean, you can do it, and it will probably work out fine, but at the very least, you'll be compromising your viability somewhat. You could wait for the beer to get fermenting and top-crop some yeast. What I would do is pitch about 75% of what the calculator advises and save the rest. There's no perfect option here, but there are three decent ones.

seriousbeef said:

After doing some research, it seems a lot of brewers make starters to 1.040 regardless of the calc. OG of the brew (excluding extreme ABV's).
So, by the time I've done a 2-step by tomorrow, I'm going to have nothing left to save for a future brew. Thoughts? Should I stick with maybe just doing close to 2L of starter?

Cheers guys :fro:

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If you like doing bigger (higher grav) beers or lagers and want to use liquid yeast, you may want to consider getting/building a stir plate. It will help you get the billions of cells required while making a much smaller starter.

Starter wort is typically around 1.040 because the purpose of it is to provide food for the yeast to eat and then multiply. That gravity is a balance between providing enough food vs. overpowering the yeast by putting it in too strong of a wort.

BigFloyd said:

If you like doing bigger (higher grav) beers or lagers and want to use liquid yeast, you may want to consider getting/building a stir plate. It will help you get the billions of cells required while making a much smaller starter.

Starter wort is typically around 1.040 because the purpose of it is to provide food for the yeast to eat and then multiply. That gravity is a balance between providing enough food vs. overpowering the yeast by putting it in too strong of a wort.

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+1 on BigFloyd's advice, higher gravity starters produce less yeast. A Stir Plate makes a huge difference in the amount of yeast a 2l starter produces.

Leading on from Bigfloyd's 1.040 comment - what is the starter gravity assumed in the Mr malty calculator?

What is your pitch rate to require a 2.5L two step starter? That seems like a lot for a beer with that SG. If you decant your current starter and step up again with another 1.4L that would seem like it would be more than sufficient . Step up with a 2L and you could salvage enough yeast for the next batch. I might be looking at the calculator wrong but that is what it came up with when I used your numbers.

chickypad said:

My thought is if you're going to the trouble of making a starter might as well do it right and pitch the correct amount of yeast. You could always wash the yeast when this batch is done if you want to save on buying new.

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Why didn't I think of washing?! Cheers.

1st Step looks like its eaten all the sugars it can (pic), we have some krausen. I was gonna fridge it and decant of ready for 2nd step..does it look ready to you guys??

I check mine by giving them a swirl, if it seems to kick up a lot of bubbles/CO2, I get the feeling that there is at least some work to do. When I give a swirl and it is more like swirling muddy water (no fizzing, etc.), I know it is done.

Maybe I'm doing it the wrong way or a slow way, but it seems to work for me.

Edit: to answer your question, to me (see description above) it does not look like it is quite done. Again, listen to someone more experienced than me and take my advice with a grain of salt.

seriousbeef said:

Threw in some figures in Mr Malty's yeast starter app.
I'm going to be brewing up a 1.067/ 6gal porter on Wednesday.
As I type this, I have 1.4L of yeast starter in front of me, with the plan to propagate a second step/batch of starter tomorrow.

My plan was to over propagate tomorrow so I have some yeast left over to decant for a future brew.
However, seeing the Mr. Malty calcuations, it seems its predicting I should be pitching a whopping 2.5L starter!

Click to expand...

Using YeastCalc and intermittent shaking I came up with a single step starter of ~3.5L, or two steps at ~1.5L each.

Actually, 2.5L isn't that big if you ever brew a lager; made a two step 1.5L > 7L starter for ~1.065 lager based on the recommeded pitch rate from the Brewer's Friend calculator.

Some multi step starters I've cold crashed, decanted, then warmed and repitched for the second stage. The last one I made using WPL007 didn't need any cold crashing before decant and second stage; that stuff drops like a rock.