How much slurry for...

[David_Trucks]

I'm doing a honey wheat soon, 4.5 gallons with an estimated OG of 1.054. I tried using yeast calculators online, but am confused when it comes to slurry. If I calculated right, it looks like I need about 8 ounces of slurry. I'm not sure about the density of the slurry and it's a few months old now - does 8 ounces seem right? Seems like too little to me. I should also point out that I'm not likely to make a starter, due to time and laziness.

On a side note, what happened to Mr. Malty?

 

[estricklin]

If it's several months old, the answer is "all of it". Seriously, if you have a couple hundred mls of slurry or whatever, just pitch it all.

 

[maierhof]

Have you used Brewersfriend yet? If no - I would - they have a way to tell how thick it is and how old it is.

Hope this helps you...

 

[estricklin]

Have you used Brewersfriend yet? If no - I would - they have a way to tell how thick it is and how old it is.

Hope this helps you...

I do love the brewer's friend calculator so can't argue with you on that. I was being short with the OP above, but I do find that when yeast has been sitting around a while it's better to error on the side of caution. Yeast calculators are great, but it's still a big guess.

 

[WoodlandBrew]

The density of the slurry depends on the propagation conditions. 1.5 billion cells per ml is normally safe.

At three months you can expect about 70% viability.

See here:
https://www.homebrewtalk.com/showthread.php?t=519995

 

[ericbw]

The density of the slurry depends on the propagation conditions. 1.5 billion cells per ml is normally safe.

At three months you can expect about 70% viability.

See here:
https://www.homebrewtalk.com/showthread.php?t=519995

And that is different than Mr. Malty would say for viability. That always shows a huge decrease in viability, but I think it bottoms out at 10%. I think that calculator (and school of thought) is very conservative. But 70% after 3 months seems higher than I've heard.

I have used about 1/4 cup of thick yeast, not even slurry, in 3 gallons. I have also carefully calculated and measured yeast for a 2-step starter and pitched a pint of the starter slurry.

Results have been the same EXCEPT that the starter takes off quicker, which helps to minimize the risk of infection.

So I would use the whole 8oz slurry, but wake it up at room temp overnight first.

There are a lot of different opinions on this!

 

[David_Trucks]

Thanks all. I actually have way more slurry than that, so I could even add more, I just got the 8 oz as a ballpark from calculations I did (I think I used Brewers friend, actually). Maybe I'll go a little higher just in case. I'm not sure what the density is.

On Brewers friend, what should I put for "slurry density"? It defaults at "1" but I don't know what that means. I'm assuming "1" is the most dense?

 

[maierhof]

Some people move that higher - but you might just want to leave that one alone unless your slurry is in a really cold environment (not frozen).

Typically I go .75 just to give me a wide berth for density and aim low - even if I am wrong on the high side it won't be by that much. Too low and you will have problems.

 

[David_Trucks]

Some people move that higher - but you might just want to leave that one alone unless your slurry is in a really cold environment (not frozen).



Typically I go .75 just to give me a wide berth for density and aim low - even if I am wrong on the high side it won't be by that much. Too low and you will have problems.

Makes sense to me, thanks!

 

[Calder]

And that is different than Mr. Malty would say for viability. That always shows a huge decrease in viability, but I think it bottoms out at 10%. I think that calculator (and school of thought) is very conservative. But 70% after 3 months seems higher than I've heard.

70% seems reasonable to me.

I think Mr. Malty goes to 10% at 2 months, and stays there until 13 months, at which point it changes to 1%. For slurry, I have absolutely no confidence in Mr. Malty for this very reason.

 

[flars]

Thanks all. I actually have way more slurry than that, so I could even add more, I just got the 8 oz as a ballpark from calculations I did (I think I used Brewers friend, actually). Maybe I'll go a little higher just in case. I'm not sure what the density is.

On Brewers friend, what should I put for "slurry density"? It defaults at "1" but I don't know what that means. I'm assuming "1" is the most dense?

The "Slurry Density? number is billions of yeast cells per milliliter. Default is one billion cells per milliliter. What you enter depends upon how much or how little non yeast material is in your slurry.