Will I overpitch using the yeast cake?

[corycorycory09]

I'm finishing up a 3.5 gallon batch of OG 1.060 beer. I fermented with WLP007 which worked nicely at 77+% apparent attenuation.

My 6.5 gallon glass carboy has a visible layer of yeast on the bottom about 1.7" high.

I want to brew 5 gallons of breakfast stout with an OG of 1.086.

According to Mr Malty I need about 150ml of yeast slurry. Based on my calculations there is over 2000 ml of 'unwashed' slurry on the bottom.

It seems like I would be massively over-pitching if I used the yeast cake in this case... but I've heard that people repitch on their cake often.

Should I remove and wash the yeast in my carboy, or am I okay to repitch my new batch on top of the cake?

 

[Yooper]

That would be a massive overpitch. Simply pour out the yeast cake, use the right amount, and save the rest in a sanitized jar(or jars) in the fridge and use it for 3 more batches.

 

[Calder]

I think you will find the carboy has a dome in the nbottom, so you don't have as much as you are thinking.

That being said, pitching on a whole cake is over-pitching.

I generally estimate a quarter of a cake is about the right amount for a pitch to a similar gravity wort. I see you are increasing the OG, so I would pitch roughly a thitd of the cake.

How do I get to a quarter of the cake? Per Jamil and White's book, the yeast at the end of fermentation will be about 6X the correct pitching rate. I figure some have died, and some still insuspension, that roughly a quarter of the cake would be in the ball-park of being the correct pitch.

No need to wash the yeast unless you really want to if you re-use within a short time.

 

[paperairplane]

The question is not will this be an over-pitch. Universally, the answer is yes.

The question is, at the home brew scale, does over-pitch really make a difference. That will generate some opinions.

 

[beardown2489]

I had a imperial stout stall the other week.

I quickly brewed up a small batch of red ale using the same yeast and tonight I'll be using the yeast below the red ale to finish the imperial stout.

I don't believe I have to worry about overpitching in this scenario. The wort is down from 1.120 to 1.058 and seems like it should be well on its way to a nice stout if I can just get it to my intended FG

PLEASE LET ME KNOW IF I NEED TO WORRY ABOUT OVER PITCHING

 

[m00ps]

I had a imperial stout stall the other week.

I quickly brewed up a small batch of red ale using the same yeast and tonight I'll be using the yeast below the red ale to finish the imperial stout.

I don't believe I have to worry about overpitching in this scenario. The wort is down from 1.120 to 1.058 and seems like it should be well on its way to a nice stout if I can just get it to my intended FG

PLEASE LET ME KNOW IF I NEED TO WORRY ABOUT OVER PITCHING

99% of the time, if you are using the entire yeast cake from one batch to another similarly volume sized batch, you are overpitching by a large factor. Try using like half the yeast cake or even less.

 

[oogaboogachiefwalkingdeer]

For my lager I have been using 1/2 of the cake or roughly a qt. For the ale's I use 1/4 of the cake or roughly a pint. No issues that I can tell.

 

[Calder]

I had a imperial stout stall the other week.

I quickly brewed up a small batch of red ale using the same yeast and tonight I'll be using the yeast below the red ale to finish the imperial stout.

I don't believe I have to worry about overpitching in this scenario. The wort is down from 1.120 to 1.058 and seems like it should be well on its way to a nice stout if I can just get it to my intended FG

PLEASE LET ME KNOW IF I NEED TO WORRY ABOUT OVER PITCHING

You are fine. Sure, if this was just wort, you could very well be over-pitching, but in this case, you are trying to finish off the beer. There will be no reproduction, and few esters created.

For that monster, you will need as much yeast as you can.

But ........ why didn't the original yeast do the job? This is the same yeast, and if the original yeast did it's job properly, there may not be many sugars left for this yeast in the cake. Without knowing why your original yeast stalled, there is no way of knowing if this will do anything. The beer is only at 8%, so it's probably not alcohol tolerance why the yeast stalled.

Just a quick question. What are you using to measure your SG? If it is a refractometer and you got approx 14.3 (equivalent to 1.058), you need to use a calculator to get actual gravity as alcohol screws up the reading. I checked and it would be about 1.020 and 13% abv.

 

[beardown2489]

The original yeast was 3 packs of safale 05. I failed to aerate like I normally do because the stone went missing.

The red ale was also Chico strain. Made a proper starter though.

Using a standard hydrometer to measure.

I pitched it onto the cake this morning. It's been 5 hours. No sign of activity. Starting to get concerned

 

[CJ-3]

I pitched it onto the cake this morning. It's been 5 hours. No sign of activity. Starting to get concerned

When you pitched onto the yeast cake did you stir it up to get the yeast back into suspension?

 

[beardown2489]

I believe so.

Still no activity. I added so maltodextrin and lactose. Wondering if I added too much. It was my first time using malto.

I used a pound of it. If this is way too much, should I just make another batch and mix the two to balance it out?

 

[GilSwillBasementBrews]

Lactose isn't fermentable so it will increase your FG. Not sure about maltodextrine but could be a reason your FG is so high still. Or at least part of the reason anyway.

 

[Brulosopher]

Will you be overpitching? Yes, technically.

Does it matter or will it make a big difference? Perhaps this is the more important question, the answer to which I'm not so sure about...

 

[erick0619]

Will you be overpitching? Yes, technically.

Does it matter or will it make a big difference? Perhaps this is the more important question, the answer to which I'm not so sure about...

Ill be looking forward to this article.

 

[Brulosopher]

Ill be looking forward to this article.

Yeast cake (overpitch) vs. starter is definitely on the list.

 

[mongoose33]

Newbie here, so please excuse if this is a naive question.

I have a brew fermenting, with a yeast cake on the bottom similar to what CodyCody has. That huge yeast cake came from a tiny packet of dry yeast (S-05).

I'm thinking that 1/4 cup of yeast cake would be MORE than enough to pitch to a new brew, given how relatively little I started with originally.

BUT--obviously everyone above, all much more experienced than I, are recommending 1/4 of the cake or more, not just 1/4 of a cup.

What am I missing? Why do you need so much more of that yeast cake than I needed when I used my tiny little bit of yeast from a packet? Is much of it dead? Or dormant and won't be revived by direct pitching?

Interesting stuff here.

 

[Calder]

Newbie here, so please excuse if this is a naive question.

I have a brew fermenting, with a yeast cake on the bottom similar to what CodyCody has. That huge yeast cake came from a tiny packet of dry yeast (S-05).

I'm thinking that 1/4 cup of yeast cake would be MORE than enough to pitch to a new brew, given how relatively little I started with originally.

BUT--obviously everyone above, all much more experienced than I, are recommending 1/4 of the cake or more, not just 1/4 of a cup.

What am I missing? Why do you need so much more of that yeast cake than I needed when I used my tiny little bit of yeast from a packet? Is much of it dead? Or dormant and won't be revived by direct pitching?

The slurry in the bottom of the fermenter contains more than just yeast. Proteins, break material, bits of hops and grains, etc.

In general, at the end of fermentation, you will have roughly 6X the 'ideal' pitch in the fermenter (don't just trust me, go read 'Yeast' it is in there somewhere - got to extract it from one of the charts).

If you account for loss of viability (dead yeast), and yeast still in suspension in the beer, a quarter of the cake is a rough guess as to the 'correct' pitch.

There are calculators you can use to estimate the amount of slurry you need, but for slurry and washed yeast, I think they are pretty much useless. Some will disagree with me on my last comment.

 

[Dan]

Newbie here, so please excuse if this is a naive question.

I have a brew fermenting, with a yeast cake on the bottom similar to what CodyCody has. That huge yeast cake came from a tiny packet of dry yeast (S-05).

I'm thinking that 1/4 cup of yeast cake would be MORE than enough to pitch to a new brew, given how relatively little I started with originally.

BUT--obviously everyone above, all much more experienced than I, are recommending 1/4 of the cake or more, not just 1/4 of a cup.

What am I missing? Why do you need so much more of that yeast cake than I needed when I used my tiny little bit of yeast from a packet? Is much of it dead? Or dormant and won't be revived by direct pitching?

Interesting stuff here.

I am by no means an expert, there are those on the forum that are. Some have chimed in some haven't

I believe you are correct in your assumption that the yeast cake as it gets called regularly; is not all yeast. It's cold break protein, dead beasties and mucky fallout. The yeast layer is above the trub, it's the fine milky layer.

 

[Dan]

Having said that. The op's pic does look very yeastie. I really am in the dark too. [emoji3]

 

[corycorycory09]

Will you be overpitching? Yes, technically.

Does it matter or will it make a big difference? Perhaps this is the more important question, the answer to which I'm not so sure about...

Having said that. The op's pic does look very yeastie. I really am in the dark too. [emoji3]

Newbie here, so please excuse if this is a naive question.

I have a brew fermenting, with a yeast cake on the bottom similar to what CodyCody has. That huge yeast cake came from a tiny packet of dry yeast (S-05).

I'm thinking that 1/4 cup of yeast cake would be MORE than enough to pitch to a new brew, given how relatively little I started with originally.

BUT--obviously everyone above, all much more experienced than I, are recommending 1/4 of the cake or more, not just 1/4 of a cup.

What am I missing? Why do you need so much more of that yeast cake than I needed when I used my tiny little bit of yeast from a packet? Is much of it dead? Or dormant and won't be revived by direct pitching?

Interesting stuff here.

This thread seems to have re-ignited so I figured I would follow up with my results. I did in fact add my wort directly onto the yeast cake shown. The beer turned out to be really good, with no noticeable off flavors I would attribute to the yeast. That said, I'd probably have to try a control batch side by side to be sure.

So Brulosopher get on it