First time yeast harvester needs help

[BrewFuerte]

Hi There, long time lurker first time poster here. I have searched the forum and Google on this topic, and there are lots of threads, but I can't seem to get clarity on exactly my issue. I am sure it is an easy one for anybody with a little experience harvesting yeast. Here is my situation:

Last night I kegged ten gallons of English Brown Ale with the intention of harvesting yeast from the cake at the bottom of the fermenter to use in a batch I am brewing today. I didn't make any effort to wash/rinse the yeast or otherwise prepare it for long term storage. I just wanted to have it to pitch today. My procedure was to rack the beer off the cake and into kegs, leaving a small amount of beer on top of the cake and swirling the whole thing into a pourable suspension. The entire contents were funneled into a 1 gallon glass growler (everything was clean and sanitized). I placed the growler in the fridge to settle for a bit. Some time later I had a large top layer of clear (well, clear but brown) beer, with yeast and trub layers below. I poured off the beer and discarded it, shook the whole thing up and put it back in the fridge. I repeated this process later when another small beer layer emerged after settling, and left the growler in in the fridge overnight. As of this morning, I have what is pictured, with what is clearly a small darker line of beer separating the other two layers. My question: Where is the yeast?

 

[meschaefer]

Your process is a bit off, but you may still have yeast in the growler depending on how long you let it sit before decanting it the first time. Washing yeast like this works because the trube will settle out first, leaving the yeast in suspension. You can then decant the growler into a clean container and thereby remove the yeast.

Decant off the liquid and fill the growler with sterilized water (boil it for 15 minutes and then allow to cool) Sanitize a second container. Take your growler filled with trube and water and swirl it up, set it aside and allow the trube to fall out of suspension. After a while you will see a much lighter colored layer of sediment starting to form - this is the yeast. Pour the clear (actually cloudy) liquid into the second container, and put it aside. (I put it in the fridge) What falls out of suspension will be mostly yeast.

 

[wilconrad]

+1 to previous poster. Add sterile water and let settle, follow yeast washing procedure similar to:
https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

 

[stpug]

I would do differently if you are truly planning on using quickly.

Here's what I would do:
1) After you've brewed your new beer and cooled it, shake up your slurry, and pour it in your new beer (or a portion of it).

That's all.

To directly answer your question, your yeast is mixed in your slurry (with trub, break material, hop particles, etc.).

 

[stpug]

Just to give you an idea of how much slurry to use,
assuming an 11 gallon ale batch at 1.060 gravity,
you would use 1 cup of slurry (~240ml). You could easily
put in an additional 1/2 cup for good measure just to
feel good

The rest you'll want to put into smaller, sanitized/sterilized jars with a small amount of headspace (less air in the jar is said to be better).

 

[BrewFuerte]

Right on, and thanks for the responses. I have read the yeast washing sticky and plan to follow that type of procedure in the future. The reason I didn't this time was that I decided to skip it since I wasn't needing to store the yeast, but didn't want to pitch onto the entire yeast cake mass. My method may have been a bad idea, but the plan was basically to scoop up some yeast from what I put in the growler and not worry too much about there being some (or a lot) of trub in it. Similar to removing a part of the yeast cake and pitching on the remainder, only backwards.

At first I had a condition like I see in many pictures on the forum: thinner liquid on top, still liquid but thicker white yeasty middle layer, thicker almost solid trub layer on bottom. The thinnest liquid, which just looked like beer, on top is what I decanted and discarded, the other two layers remained. Where I became confused was when I got the condition in the picture, which had three layers with the thinnest beer layer in the middle. My gut told me that the bottom layer was mostly trub and the top layer mostly yeast, but I hadn't seen pictures with the thin clear layer in the middle, and I second guessed myself thinking the top layer might just be some kind of foamy krausen layer that is not the richest in yeast.

I am pretty sure that if I just shook the whole thing up and pitched a cup or so per 5.5 gallon batch, it would be fine, but since I got the layers it raised the question of perhaps being able to take one layer over the others getting more pure yeast and leaving more trub behind. Along with that opportunity came the risk of picking the wrong layer and getting a lower than desired pitching rate.

All that said, is it you guys' advice to add sterile water now and do a yeast washing process, or is that something for next time? Is my thinking in using one layer of this slurry over the others misguided? Thanks!

 

[BrewFuerte]

I would do differently if you are truly planning on using quickly.

Here's what I would do:
1) After you've brewed your new beer and cooled it, shake up your slurry, and pour it in your new beer (or a portion of it).

That's all.

To directly answer your question, your yeast is mixed in your slurry (with trub, break material, hop particles, etc.).

Thanks, you posted this as I was posting last. You answered the questions I was asking, I think. Thanks again. I am doing an 11 gallon batch of 1.08+, so I will use about 2 cups or so.

 

[stpug]

All that said, is it you guys' advice to add sterile water now and do a yeast washing process, or is that something for next time? Is my thinking in using one layer of this slurry over the others misguided? Thanks!

I, myself, would not wash/rinse this yeast if you're using it right away. I would shake it up into a homogeneous solution and pitch the correct amount of slurry. You are guaranteed to get plenty of viable yeast that way (along with old trub, dead yeast, etc); the extra "stuff" will simply settle out in the fermenter again.

I have actually moved away from a hardcore washing/rinsing methodology, and moved to more of a "get the crudiest crud out of there" but keep the rest.

The problem with using one layer of another is that you'll be picking a conglomeration of a specific kind of yeast and without having the specialized equipment to discern what is in what layer, you might not be picking the most appropriate layer. Thus my suggestion to shake it up and take a nice mix of it all.

 

[BrewFuerte]

Thus my suggestion to shake it up and take a nice mix of it all.

Makes complete sense to me. If I want no crud next time I can do it the "right" way. If it doesn't ferment properly this time, that is a clue that the big pour off of beer I did early in the process took my yeast down the drain. I don't think that is the case though. What I have now looks and smells too much like good yeast, I think...

 

[BrewFuerte]

I guess the slurry had yeast in it. 1.08 IIPA now bubbling away happily. I appreciate the help everyone!

 

[EarlyAmateurZymurgist]

Decant off the liquid and fill the growler with sterilized water (boil it for 15 minutes and then allow to cool)

Boiled water is not sterile. Water needs to be raised to 250F/121C and held there for 15 minutes to render it sterile. If you do not believe me, look up the word "autoclave."

 

[EarlyAmateurZymurgist]

i would do differently if you are truly planning on using quickly.

Here's what i would do:
1) after you've brewed your new beer and cooled it, shake up your slurry, and pour it in your new beer (or a portion of it).

That's all.

To directly answer your question, your yeast is mixed in your slurry (with trub, break material, hop particles, etc.).

+1

 

[BrewFuerte]

Yes,that is what I did. It worked. Of course you are right about autoclaving aka pressure cooking. Some spores are not killed at boiling. For the work I am doing right now this is not critical, while for long term storage it may be. I am sure there are plenty of folks that do not autoclave and do just fine. Best practices and things that work well enough most of the time are not necessarily one and the same.

 

[EarlyAmateurZymurgist]

Yes,that is what I did. It worked. Of course you are right about autoclaving aka pressure cooking. Some spores are not killed at boiling. For the work I am doing right now this is not critical, while for long term storage it may be. I am sure there are plenty of folks that do not autoclave and do just fine. Best practices and things that work well enough most of the time are not necessarily one and the same.

It's not that simple. A yeast culture "owns" a batch of wort by consuming all of the oxygen, reducing the pH, and producing ethanol (ethanol is toxic to most microflora). Decanting the green beer and adding boiled (non-sterile) water removes the ethanol and raises the culture's pH, which allows spores to germinate and use dead yeast cells as a nitrogen source.

Maintaining a yeast culture in liquid form is about making tradeoffs. It is always easier to resuscitate a weak culture than it is to clean up an infected culture. I have brewed almost exclusively with home lab cultured yeast since 1993. I used to plate cultures for friends who rinsed yeast with boiled water. More often than not, the cultures were infected with low levels of bacteria and mold. A low-level infection gets amplified every time a culture is repitched. I streaked the plate shown below from a culture that I grew from bottle of bottle-conditioned beer. This is what a bacteria and mold-free culture looks like on a plate:

As an aside: the colonies in the red rectangle are each the offspring of a single yeast cell; therefore, they are single-cell isolates. Single-cell isolation is how pure cultures are created (Emil Hansen was the first scientist to isolate a pure yeast culture). I transferred these colonies to separate slants.

 

[EarlyAmateurZymurgist]

duplicate

 

[BrewFuerte]

It's not that simple. A yeast culture "owns" a batch of wort by consuming all of the oxygen, reducing the pH, and producing ethanol (ethanol is toxic to most microflora). Decanting the green beer and adding boiled (non-sterile) water removes the ethanol and raises the culture's pH, which allows spores to germinate and use dead yeast cells as a nitrogen source.

Maintaining a yeast culture in liquid form is about making tradeoffs. It is always easier to resuscitate a weak culture than it is to clean up an infected culture. I have brewed almost exclusively with home lab cultured yeast since 1993. I used to plate cultures for friends who rinsed yeast with boiled water. More often than not, the cultures were infected with low levels of bacteria and mold. A low-level infection gets amplified every time a culture is repitched. I streaked the plate shown below from a culture that I grew from bottle of bottle-conditioned beer. This is what a bacteria and mold-free culture looks like on a plate:

As an aside: the colonies in the red rectangle are each the offspring of a single yeast cell; therefore, they are single-cell isolates. Single-cell isolation is how pure cultures are created (Emil Hansen was the first scientist to isolate a pure yeast culture). I transferred these colonies to separate slants.

OK, thanks.