my yeast cells

[SimoB]

Hey all...

sorry for the repetitive post about yeast. Doing lots of research and just one more thing I can't seem to settle on.

I had about 20ml of yeast slurry. Compacted as it's been in the fridge for just over a week.

Using the calculators. I estimated that my concentration was about the 3.5 billion/ml.

So 20 x 3.5 = 70 billion.

for my beer I need 236 billion.

I created a 1L starter. going off the above number the calculator estimated this first step would get me 149 billion. So still under.

So I am going to step it up with a 2 L starter (decant and pour fresh cooled wort on top of yeast in flask, only have 1 flask)

This step, the calculator gets me 333 billion cells.

Now for my question... Does this mean I would be over pitching??? How would I go about getting closer to the right cell count.

Also, the washed yeast slurry compacted calculator states that I need about 90ml of yeast to pitch. Looking at my starter I would have that already?


Hope all that makes sense. What do I do???

Cheers!

 

[Black n Tan]

A lot of people use these calculators but they are just estimates and are depend on a wide range of assumptions. The first time you use them you should aim to pitch at the right rate: there is not point using a calculator and then ignoring the result. Once you have some experience you may wish to make adjustments. If I were you I would just do a 3L starter and that should get you to where you want to be. There is no need for a step starter IMHO especially as you are using a stir plate.

 

[SimoB]

A lot of people use these calculators but they are just estimates and are depend on a wide range of assumptions. The first time you use them you should aim to pitch at the right rate: there is not point using a calculator and then ignoring the result. Once you have some experience you may wish to make adjustments. If I were you I would just do a 3L starter and that should get you to where you want to be. There is no need for a step starter IMHO especially as you are using a stir plate.

Yeah thanks mate - Not planning on ignoring the results and the aim of this question was to assure I get to the right pitching rate. Also these numbers are based on the shaking method as I don't have my stir plate yet, it's in transit.

Would you just pitch the starter out of the 1L ? Or step up as I have already created the 1L starter and is currently in the fridge. This is a real life example which I am trying to figure out.

Cheers,

 

[Black n Tan]

Keep it in the fridge overnight and decant the spent wort and pitch just the yeast into the next starter. Where in Melbourne are you?

 

[Kiwifirst]

I am doing a Dunkel which wants 400bill. I did a 2l starter at brew temp 10-12c for three days. Dumped the wort and dropped another 2l starter on top of the cake. Going off very nicely.

I am definitely erring on the side over perceived over pitch, rather than under because I really don't know how healthy the yeast is to start. The first packet I picked up had a date of Dec 13th 2013. That wouldn't have done much in getting my first 200bill step.

 

[SimoB]

Keep it in the fridge overnight and decant the spent wort and pitch just the yeast into the next starter. Where in Melbourne are you?

In Vermont mate.

 

[SimoB]

I am doing a Dunkel which wants 400bill. I did a 2l starter at brew temp 10-12c for three days. Dumped the wort and dropped another 2l starter on top of the cake. Going off very nicely.

I am definitely erring on the side over perceived over pitch, rather than under because I really don't know how healthy the yeast is to start. The first packet I picked up had a date of Dec 13th 2013. That wouldn't have done much in getting my first 200bill step.

I was reading that it's also possible to over pitch a starter. Instead of multiplying they go straight into fermentation mode and don't get the same growth rate. I'm doing a lot of reading which is why im probably getting confused haha... I'm no expert that's for sure.

 

[Kiwifirst]

I think you'd need to massively over pitch. I can certainly see that happening when you drop a new brew on an old yeast cake. I brewed something last year, forget what, and it was down to FG in 3 days. I assumed that was from over pitching on the yeast cake.

Now I rinse my yeast and make starters.

 

[Mardoo]

I'm relatively new to starters and I'm pretty sure I've been overpitching, probably similar to the level you're looking at (needing around 230 and getting around 330). I've been getting lightning fast ferments (up to 60 point drop in 36 hours), not much flavor development with English yeast that should be giving me more esters, very minimal body to the beer and a touch of fusels, with this feedback coming from judging in comps. All of these are said to be symptoms of over-pitching.

I've started scaling back to the calculators' recommended amounts by very roughly estimating yeast count based on volume and thickness of slurry, using the amounts as stated in the washed yeast calculator on yeastcalc. I figured starter-based slurry would be similar in counts to washed yeast. I've only done this on my beer which is currently fermenting, but so far am happy with results, with two days to get going before I started to see much drop in SG and a slower rate of drop. So I can't comment on affect on the final beer, but I'm happy with what I'm seeing so far.

So, based on the results I was getting in a similar situation I've chosen to try not to overpitch. That's my experience FWIW.

 

[Black n Tan]

In Vermont mate.

I would offer a loan of my stir plate but I am in Ascot Vale, so not just around the corner. You could just make a smaller second starter, say another 1L, so you don't over-pitch. However the shaking method is so variable and I suspect you may well end up with less cells than calculated, so a 2L starter may just be fine. Sorry not a definite answer I know, because there are so many variables.

 

[SimoB]

All good.. I bit the bullet and did a 2l. get my stir plate next week so lesson learnt. Thanks for the offer mate

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[Fat Bastard]

I'm relatively new to starters and I'm pretty sure I've been overpitching, probably similar to the level you're looking at (needing around 230 and getting around 330). I've been getting lightning fast ferments (up to 60 point drop in 36 hours), not much flavor development with English yeast that should be giving me more esters, very minimal body to the beer and a touch of fusels, with this feedback coming from judging in comps. All of these are said to be symptoms of over-pitching.

I've started scaling back to the calculators' recommended amounts by very roughly estimating yeast count based on volume and thickness of slurry, using the amounts as stated in the washed yeast calculator on yeastcalc. I figured starter-based slurry would be similar in counts to washed yeast. I've only done this on my beer which is currently fermenting, but so far am happy with results, with two days to get going before I started to see much drop in SG and a slower rate of drop. So I can't comment on affect on the final beer, but I'm happy with what I'm seeing so far.

So, based on the results I was getting in a similar situation I've chosen to try not to overpitch. That's my experience FWIW.

Have you also been getting over attenuated beers? Most of mine end up at a lower FG than expected. I use a 2l stir plate starter pitched whole after 24 hours growth. I get reasonably rapid ferments and very clean, dry beer, particularly with US yeasts, although with the last English ale yeast I used it under attenuated, but was still very clean tasting, although I'm putting that down to the fact it was in an 8% imperial porter.

Not getting any fusels or anything from it though.

 

[Mardoo]

Yep, average of 7 points lower than calculated, with all aspects of the mash hitting their targets. Also much thinner body than expected.

The fusels I'm not positive on, but the judges who mentioned them clearly knew their stuff from the comments. However there's an alcohol "bitterness" (for lack of better words) I can taste that I sometimes see in cheap wines, so I'm guessing that's the fusel alcohol. Definitely not hop bitterness.

 

[SimoB]

I'm relatively new to starters and I'm pretty sure I've been overpitching, probably similar to the level you're looking at (needing around 230 and getting around 330). I've been getting lightning fast ferments (up to 60 point drop in 36 hours), not much flavor development with English yeast that should be giving me more esters, very minimal body to the beer and a touch of fusels, with this feedback coming from judging in comps. All of these are said to be symptoms of over-pitching.

I've started scaling back to the calculators' recommended amounts by very roughly estimating yeast count based on volume and thickness of slurry, using the amounts as stated in the washed yeast calculator on yeastcalc. I figured starter-based slurry would be similar in counts to washed yeast. I've only done this on my beer which is currently fermenting, but so far am happy with results, with two days to get going before I started to see much drop in SG and a slower rate of drop. So I can't comment on affect on the final beer, but I'm happy with what I'm seeing so far.

So, based on the results I was getting in a similar situation I've chosen to try not to overpitch. That's my experience FWIW.

sorry mate I missed this post. Let me know your results as that will answer my question. Cheers

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[Fat Bastard]

Yep, average of 7 points lower than calculated, with all aspects of the mash hitting their targets. Also much thinner body than expected.

The fusels I'm not positive on, but the judges who mentioned them clearly knew their stuff from the comments. However there's an alcohol "bitterness" (for lack of better words) I can taste that I sometimes see in cheap wines, so I'm guessing that's the fusel alcohol. Definitely not hop bitterness.

Sounds exactly like where I'm at right now. I've played with the yeastcalc and the calculator on Beersmith and it looks like I'm overpitching by about 100billion cells from my 2l starters.

I get a bit more bitterness than I've wanted, but I've been putting that down to the fact my beers are finishing lower than expected.

I was going to start a thread about this, but looks like you've saved me the trouble! Now I have another thing to think about!

Cheers,

FB

 

[Mardoo]

FB, that's interesting about the bitterness and lower FG. I hadn't thought of that. However, the sensation I'm talking about seems to me to be different than hop bitterness. I actually am unsure how to describe it well. Bitterness is the best I can do. I'll post more when the current beer has finished fermenting, but so far I'm happy with the ferment and the flavor.