Why harvest yeast cakes?

I have seen a lot of people talking about harvesting and reusing their yeast cakes at the end of the primary.

What is the purpose of doing this. The only thing I can think of is either the yeast is expensive (I just bought a kit and it came with it) or that certain strains can be difficult to obtain.

If anyone could give me a little more info regarding this or point me in the right direction. (cause I am sure that it is out there 100 times over)

There are a couple of reasons to harvest yeast- one is the cost! Liquid yeast can cost $7-$8 a pack and if you reuse it three times, the cost per batch jumps way down.

Secondly, instead of making a starter, you can just pitch it right on the cake which then works as a huge starter. It'll really get your fermentation going well!

This isn't really an issue with dry yeasts, which are usually $1 or so and have plenty of cells to start fermentation.

Also with yeasts that are hard to find such as the Pacman strand you can use the cake a few times to make more brew

What she said! Plus, some of the liquid strains aren't available year round. Some others are only available for a limited time and then they are gone.

For example, I like White Labs' WLP036 Dusseldorf Alt yeast a lot, but it's only available in May and June. It seems I always miss getting it and have to resort to using their WLP029 for my Alts. Well, the next time I get my hands on some WLP036, you can bet I'm going to do a couple of batches using it, then harvest it and store it for future use!

yep, mainly cost. liquid yeast is about $8/vial. gets quite spendy, specially if you're making a big batch and need more than one vial! gah!

it is never necessary with dry yeast as it is cheap, stores well and usually easily obtained.

At $7.00 a vial I have used and reused the yeast up to 20 times and more.

That's $.35 each use alone for specialty yeast that I know is alive.

How do you go about harvesting the yeast ?

Do you just put the next batch of wort right in on top of the yeast thats left from the last batch ?

Do a search on washing yeast.

Would it be easier to, say, take a White Labs vial and use around 1/3 of it in a big starter and save the rest for later as opposed to washing yeast after fermentation? I've dumped on the cake before, but I've never washed yeast for later use.

Not really. By making a starter using only 1/3 of a vial you'll have to step up the starter twice to get enough yeast going.

With a yeast cake out of the primary you can effectually wash it and split it to have enough yeast for 5 more batches. Let's use 5 for this explanation (5+1=6).

These 5 batches can be split 5 more times (6 + 25 = 31) also. So now we're talking 31 times using the same washed yeast.

You can go even further with a 4th generation yeast (5 X 25 = 125) and have enough yeast to make 156 batches of brew.

At $7 a vial that comes to 4 cents per batch for yeast. :rockin:

At $7 a vial for 156 batches comes to...$1092.00!!!

Your call.

Buford said:

Would it be easier to, say, take a White Labs vial and use around 1/3 of it in a big starter and save the rest for later as opposed to washing yeast after fermentation? I've dumped on the cake before, but I've never washed yeast for later use.

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Not really. Washing yeast is actually quite easy. I have two, two quart apple juice bottles. Obviously, sanitize the crap out of them before use. Then, after you rack your beer, take about a quart of boiled and cooled water and mix it up with the trub...then pout it all into the bottle (you may want to have an extra sanitized jar laying around as sometimes it wont all fit in one bottle), then let it settle for a couple of hours, agitating it every so often, to keep the yeast in suspension while allowing the heavier stuff to settle. Then carefully transfer the liquid on top to the second bottle. Again, agitating occcasionally and allowing the heavier stuff to fall out. In the meantime, clean and sanitize the first bottle. Then after an hour or two, dump the liquid from the second bottle, back into the first bottle and chill. When the liquid chills, the yeast will fall out of suspension and collect on the bottom of the bottle. Dump off the majority of the liquid, and add your yeast to a sanitized jar and label. I know it sounds like a lot, but it really is not.

Ive got a question to add to this, I have never washed yeast but I am hooked on this hobby so I think I am going to start. There are so many different kinds of yeast, and brewing so many different kinds of beer by the time I get to brew something that uses a certain yeast I would think it would be sitting in the fridge to long and just have to buy some new stuff anyways. Or is there a couple main yeasts that I can use for, ales, hefe's, lagers, etc. instead of having the huge choice on yeast and still have the beer taste alright?

Sure! You could keep one or two "standards" on hand. I saved pacman when I had it because I really liked it. But those available now, I'd recommend 1056- American Ale yeast for one. You can use it in just about anything. I'd say Bavarian Lager yeast for the lager yeast- that's a good all purpose lager yeast. For wheats, I have no idea.

Mot: The trick is to find a yeast you really like and make it your standard house yeast. You know, the one you'll use the most.

You can mix the washed yeast with glycerin and freeze the yeast to keep it from aging.

Me, I refill the vials and fill baby food jars. I label them with the name of the yeast, the date, and the batch number(s) used in as well as the generation.

As an experiment I've even saved and reused dry yeasts with success.

homebrewer_99 said:

Mot: The trick is to find a yeast you really like and make it your standard house yeast. You know, the one you'll use the most.

You can mix the washed yeast with glycerin and freeze the yeast to keep it from aging.

Me, I refill the vials and fill baby food jars. I label them with the name of the yeast, the date, and the batch number(s) used in as well as the generation.

As an experiment I've even saved and reused dry yeasts with success.

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thats kind of what I thought but wasnt sure...I dont have enough batches under my belt to know what yeasts i like and dont like.

one more thing how long can you keep it in the fridge before it goes bad or before you should have froze it with glycerine. Weeks, months?

Depends on the coldness of the fridge and sanitation of the containers really.

I soak my vials and baby food jars in Star San for an extended period of time, sometimes all day (I forget it's in there). I also scrub them with a brush in the Star San, shake it off and fill while still wet.

I made another batch of Barkshack Ginger Mead a week or so ago (just put up 4 more baby food jars of the yeast from its primary last night). The yeast I used for it was Lalvin D47 that was from batch #6004 that I made in March 2006! It's been sitting in my fridge that long...

The FG of the mead was .996. Since it was that low and completely fermented out there was no need to wash it. The mead that was on top of the yeast protected it. I just let it sit in a bottle with an airlock the whole time.

With beer yeast you want to wash it to separate the trub from the yeast. There really isn't any in mead.

homebrewer_99 said:

Depends on the coldness of the fridge and sanitation of the containers really.

I soak my vials and baby food jars in Star San for an extended period of time, sometimes all day (I forget it's in there). I also scrub them with a brush in the Star San, shake it off and fill while still wet.

I made another batch of Barkshack Ginger Mead a week or so ago (just put up 4 more baby food jars of the yeast from its primary last night). The yeast I used for it was Lalvin D47 that was from batch #6004 that I made in March 2006! It's been sitting in my fridge that long...

The FG of the mead was .996. Since it was that low and completely fermented out there was no need to wash it. The mead that was on top of the yeast protected it. I just let it sit in a bottle with an airlock the whole time.

With beer yeast you want to wash it to separate the trub from the yeast. There really isn't any in mead.

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so whats the longest you have kept your beer yeast in the fridge?

mot said:

so whats the longest you have kept your beer yeast in the fridge?

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Hard to say right up front on an exact length of time.

I do have washed yeast and packaged yeast that I know are over 1 year old. I will eventually use them.

My favorite Weizen yeast, WLP351, is only available in Jul/Aug. The last time I purchased it was last July. I could toss all of it out and start again, but I don't see any need to do that since my yeast is still healthy. I have washed yeast from 2, 3, and 4th generations of it. And I always use the oldest first. I lost a couple of baby food jars, at least they looked "ugly" enough to not use. With all the yeast I have on hand I won't second guess if it is healthy or not. If it looks, smells or tastes bad it's out of there.

Sometimes I'll combine 2 baby food jars (same strain) of the oldest yeast to make a starter just to reduce the inventory.

For the most part much of my yeast is over 6 months old when I use it. Don't get me wrong, I have "new" unused yeast in the inventory also. But they are usually another strain for another time/style.

The trick is to always make a starter. OK, even I break my own rules sometimes, but only when I am using freshly washed (within a week or two) yeast that I know is alive.

homebrewer_99 said:

Hard to say right up front on an exact length of time.

I do have washed yeast and packaged yeast that I know are over 1 year old. I will eventually use them.

My favorite Weizen yeast, WLP351, is only available in Jul/Aug. The last time I purchased it was last July. I could toss all of it out and start again, but I don't see any need to do that since my yeast is still healthy. I have washed yeast from 2, 3, and 4th generations of it. And I always use the oldest first. I lost a couple of baby food jars, at least they looked "ugly" enough to not use. With all the yeast I have on hand I won't second guess if it is healthy or not. If it looks, smells or tastes bad it's out of there.

Sometimes I'll combine 2 baby food jars (same strain) of the oldest yeast to make a starter just to reduce the inventory.

For the most part much of my yeast is over 6 months old when I use it. Don't get me wrong, I have "new" unused yeast in the inventory also. But they are usually another strain for another time/style.

The trick is to always make a starter. OK, even I break my own rules sometimes, but only when I am using freshly washed (within a week or two) yeast that I know is alive.

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cool thanks man, I guess I will just have to start trying it out and hope I dont screw it up. I take it you can visually see if you screwed it up and got some contaminents in there

Mutilated1 said:

How do you go about harvesting the yeast ?

Do you just put the next batch of wort right in on top of the yeast thats left from the last batch ?

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I like to start out by filling a large apple juice jar half way with boiled/cooled water…toss it into the carboy…swirl it all around and pour back into the apple juice jar.

Let it sit for about 10-15 minutes and then pour gently into another empty apple juice jar…leaving behind the last 1/8 inch of sediment. This usually gives me pretty clean yeast.

Each of the jars below came from separate batches and each is enough to start three more batches. The one on the right has been in the fridge for about 4-5 days, the one in the middle I just harvested and the one on the left is about a day old (not refrigerated).

I’ll either store these in beer bottles or just leave the jug on a shelf if I’m planning on using within a week or so.

mot said:

cool thanks man, I guess I will just have to start trying it out and hope I dont screw it up. I take it you can visually see if you screwed it up and got some contaminents in there

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Yes. There will be another layer separating on top of the yeast, like a scum/mold layer.

homebrewer_99 said:

You can mix the washed yeast with glycerin and freeze the yeast to keep it from aging.

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How do you thaw out the yeast? Let it sit at 70 degrees? Can Glycerin be bought at an LHBS?

Thanks!

Uncle Argyle said:

How do you thaw out the yeast? Let it sit at 70 degrees? Can Glycerin be bought at an LHBS?

Thanks!

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Yes and yes.

Thanks! I was just about to edit my post and say that I found the answer in the Wiki...next time I'll read the Wiki first!

BierMuncher said:

my cool pic

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I'm always impressed with that amount of yeast in that right bottle

So could one wash their yeast cake...then dilute it to 1 gal to bottle say 10 beer bottles of yeast?

They would be diluted but you could pour off the water on top then step up a starter right?

Since we are on the topic of harvesting yeast. I recently racked two primarys. I left about 1" of liquid over the yeast cake and just let both vessels sit there for I was going to clean them later. Now I am thinking about washing them. Is it viable that I would be able to wash with only 1" of liquid above the yeast cake for about 1 week?

greenhornet said:

So could one wash their yeast cake...then dilute it to 1 gal to bottle say 10 beer bottles of yeast?

They would be diluted but you could pour off the water on top then step up a starter right?

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Yes, you could, but why 10? You'd have double the yeast if you used only 5. Remember, from each of those 5 you'll get 5 more, and 5 more from those 5....

anthrobe said:

Since we are on the topic of harvesting yeast. I recently racked two primarys. I left about 1" of liquid over the yeast cake and just let both vessels sit there for I was going to clean them later. Now I am thinking about washing them. Is it viable that I would be able to wash with only 1" of liquid above the yeast cake for about 1 week?

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I wouldn't let it sit that long. When washing you'll be adding about 1/2 gal of water.

The addition of water serves several purposes.

1 it dilutes the beer and stops the fermentation process,
2 it allows you to swirl/shake the yeast from the sludge,
3 allows the heavier sludge to separate (from the yeast floating in the water) and fallout without taking too much yeast with it,
4 gives you something to look at after the sediment falls out...since you only pour off the liquid (to save) and pour the heavier sediment down the drain.

Washing does not take a long time and is fairly easy to do correctly...and the benefits are worth it.

greenhornet said:

So could one wash their yeast cake...then dilute it to 1 gal to bottle say 10 beer bottles of yeast?

They would be diluted but you could pour off the water on top then step up a starter right?

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10 bottles may be thinning the batch a little too much. Depends on the flocculation rate. I'd say that any five gallon batch would safely produce 5 vials of yeast.

PS - I never use a starter with my harvested yeast because there is so much to begin with. Not saying that's the right thing to do.

BierMuncher said:

...I never use a starter with my harvested yeast because there is so much to begin with. Not saying that's the right thing to do...

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Nothing wrong with that. It's already proved that it is good yeast.

Two noobie questions. What does it mean to use a started for yeast. (On my first batch we just tossed in the dry yeast and stirred.

Also, what is flocculation?

Wrey said:

Two noobie questions. What does it mean to use a started for yeast. (On my first batch we just tossed in the dry yeast and stirred.

Also, what is flocculation?

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A question I can answer.
mrmalty.com is a good reference for yeast questions.
Basically a starter is a mini brew to allow the yeast to reproduce and get ready for fermenting your main batch. It is made by boiling 1/2 cup DME in 1quart or liter of water (to do larger starters just scale the amounts). Allow the mini wort to cool, agitate well to aerate and then pitch your vial or pack of liquid yeast. Leave sit for 12-48 hours then pitch the starter into your just brewed wort. This ensures enough yeast for the fermentation and reduces the lag time. It is usually unnecessary to make a starter for dry yeast as dry yeast packs contain a much larger cell count and if you do need more than one packet of yeast it is easier and often cheaper to just pitch a second packet.

Flocculation is how rapidly the yeast settle out of the beer. A highly flocculating yeast will quickly form a dense layer on the bottom of the carboy leaving a clear beer. A low flocculating yeast will leave your beer cloudy for much longer and will be more easily mixed into the beer when you move it. Most wheat beer yeast are low flocculating giving the beer the characteristic cloudy look and yeasty flavor.

Craig

To add to the above, it is actually bad to use a starter with dry yeast. They have been "frozen" in a metabolic state that is ready to ferment your beer, not reproduce as they would in a starter.

use liquid, then it gives you an excuse for building a stirplate

Uncle Argyle said:

How do you thaw out the yeast? Let it sit at 70 degrees? Can Glycerin be bought at an LHBS?

Thanks!

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It can also be found at most any drugstore/pharmacy.

Can you use distilled water for washing yeast, and if so, is there any benefit to doing so?

I've read a few things about washing with distilled water...basicly the yeast have a longer shelf life if they are stored under distilled water...

It is good idea.