Fermenting on top of old yeast cake?

[Dutch_Brewer]

I've been reading about harvesting yeast and found out you can wash yeast or use more complex methods involving acids.

The basis is seperating the yeast from the trub and using that for a new brew.

Now on google i've found some people telling that washing is not necessary and you can just throw away half of the trub and pour the new wort right on top of the old half of the yeast cake? Is that true, or is this bad practise if so, why?

 

[Miraculix]

You do not need to throw anything away, just pour in the wort directly on the yeast cake. But be prepared for an amazingly aggressive and quick fermentation

I do this sometimes multiple times with the same yeastcake, one package of yeast, three beers, one after each other.

You might not want to throw in a light beer on a yeastcake of a dark beer for flavour reasons though, otherwise it is a nice thing to do.

 

[RM-MN]

I've been reading about harvesting yeast and found out you can wash yeast or use more complex methods involving acids.

The basis is seperating the yeast from the trub and using that for a new brew.

Now on google i've found some people telling that washing is not necessary and you can just throw away half of the trub and pour the new wort right on top of the old half of the yeast cake? Is that true, or is this bad practise if so, why?

Using the entire yeast cake will be overpitching by about a factor of 4. Pour off 3/4 of the cake and divide it into 3 pint jars and you will have a yeast bank for future brews. Put the lid on loosely as the beer will outgas CO2 for quite some time and your pint jars aren't made to hold pressure.

 

[Dutch_Brewer]

Using the entire yeast cake will be overpitching by about a factor of 4. Pour off 3/4 of the cake and divide it into 3 pint jars and you will have a yeast bank for future brews. Put the lid on loosely as the beer will outgas CO2 for quite some time and your pint jars aren't made to hold pressure.

And store in fridge like some people say? And don't wash it?

When re-using these stored jars do i need to do a yeast starter with wort and yeast nutrient or good to go?

 

[Miraculix]

Don't see a problem with over pitching!

 

[RM-MN]

And store in fridge like some people say? And don't wash it?

When re-using these stored jars do i need to do a yeast starter with wort and yeast nutrient or good to go?

The trub has already been on the bottom of your fermenter for a week or more. Washing it probably doesn't gain you much. As to whether to use a starter or not would depend on the temperature and time in the refrigerator. Yeast stores pretty well but there will be some mortality so if you store for months a starter might be a good idea. A week or two wouldn't need a starter.

 

[RM-MN]

Don't see a problem with over pitching!

I've seen anecdotal reports that heavily overpitching can lead to a drier beer.

 

[Dutch_Brewer]

thank's I'm learning so much here!

But I do have to store them in the fridge right? After how long put the cap on the jar?

 

[Kharnynb]

cap it, just don't tighten the cap too much.

I use glass pickle jars, the big 1 liter ones,(grote kilo augurken pot ;D)

generally after i transfer the beer to my bottling bucket, i drop a liter of boiled and cooled water on the cake, swirl it a bit and then wait about 30 minutes, pour off the top liter into the jar for immediate repitching or split in 3-4 jars for later use and store in the fridge

 

[Miraculix]

The yeast will settle in the fridge. Before pitching, discard the clear liquid on top of the yeast and before doing that, allow the yeast to get room temperature for a few hours or half a day.

If you want to pitch it within the next days after harvesting, then there is no cooling required. Just cover the Glas with foil or similar solution.

 

[IslandLizard]

After racking I leave about 1-2 quarts of beer behind, with which I swirl up the yeast cake, and pour into a 64oz (half gallon) glass pickle jar. If it's very trubby (e.g., dry hop) I let it settle out for 5-30 minutes (use some judgment), then divide the liquid on top (which contains mostly yeast) over 2-4 pint mason jars, leaving the trub behind in the large jar. If the yeast cake is fairly clean I divide them up immediately. The pints get stored in the fridge, labeled and dated.

The only thing I tend to differ with what @Kharnynb said, yeast stores best under beer, not water.

If used within 2 months there's usually no need for a starter. If longer, I take a few "tablespoons" out and build a new starter. Don't make a traditional starter from the whole jar, but you could make a vitality starter with it, if you have a large enough vessel to do so.

 

[Dcpcooks]

thank's I'm learning so much here!

But I do have to store them in the fridge right? After how long put the cap on the jar?

Best practice would be to rinse with sterile water and let the trub and hops settle out, then decant the yeast into sterile mason jars and store cold.

 

[RM-MN]

Here's a little more reading for you. http://www.woodlandbrew.com/2012/12/refrigeration-effects-on-yeast-viability.html

 

[Sailingeric]

And store in fridge like some people say? And don't wash it?

When re-using these stored jars do i need to do a yeast starter with wort and yeast nutrient or good to go?

I have done just that, pour some of the trub into the jars, use in again in a month or so and all was just fine.

 

[Dutch_Brewer]

Here's a little more reading for you. http://www.woodlandbrew.com/2012/12/refrigeration-effects-on-yeast-viability.html

thank's i will read that now! When I do use a starter because the yeast is some older do i add wort or nutrient or both?

 

[RM-MN]

Wort contains all the yeast need for growing except oxygen. Make sure to aerate your wort.

 

[DurtyChemist]

Enjoy.
http://brulosophy.com/projects/exbeeriments/

Plenty of yeast pitching experiments here you can look over. As some have said don't pitch a light beer on a dark beer. Do something like a 1.045, 1.060-1.08, 1.100 in that order and light to darker and you'll be fine. You could also do something like a pale ale, brown ale, barleywine.

 

[Dutch_Brewer]

cap it, just don't tighten the cap too much.

I use glass pickle jars, the big 1 liter ones,(grote kilo augurken pot ;D)

generally after i transfer the beer to my bottling bucket, i drop a liter of boiled and cooled water on the cake, swirl it a bit and then wait about 30 minutes, pour off the top liter into the jar for immediate repitching or split in 3-4 jars for later use and store in the fridge

Thank's i'm a big fan of "augurken " so I have enough of these jars!

 

[Dutch_Brewer]

Wort contains all the yeast need for growing except oxygen. Make sure to aerate your wort.

Oke!

After putting the yeast in the fridge and having the lid on loosely when do i tighten that lid, or never?