How much yeast to add to a bottle to condition a Duvel clone?

[RoomWithABrew]

Hi
I've been following a Duvel clone recipe and the information in a few articles about how Duvel is produced.

Recipe has been done, lagering phase under pressure with 2.2 vols.

I aim to counter pressure fill into bottles as Duvel do and they apparently add fresh yeast and sugar to get a target of 4 vols.

Managed to work out the dextrose needed per bottle but I have no idea how much yeast I should add. I'm going to make a very small starter and divide it up to dose each bottle.

Any ideas?

 

[Agentgonzo]

Hi
I've been following a Duvel clone recipe and the information in a few articles about how Duvel is produced.

Recipe has been done, lagering phase under pressure with 2.2 vols.

I aim to counter pressure fill into bottles as Duvel do and they apparently add fresh yeast and sugar to get a target of 4 vols.

Managed to work out the dextrose needed per bottle but I have no idea how much yeast I should add. I'm going to make a very small starter and divide it up to dose each bottle.

Any ideas?

According to Brew like a Monk, Duvel use 1 million cells per millilitre for refermentation in the bottle.
I have no idea what that equates to in grams or ml though. .

 

[RoomWithABrew]

Damm I didn't check that book, next question how many millilitres at that cell density, couple of ml ?

 

[Agentgonzo]

Damm I didn't check that book, next question how many millilitres at that cell density, couple of ml ?

That, unfortunately, varies by yeast strain. And I have absolutely no idea.
Fortunately, there may be this information on file at Heriot Watt. My wife says "contact professor Susan Dewer"... or find someone on their brewing and distilling course (@DocAnna ) to ask the department on your behalf!

(Or someone may have a rough answer that is good enough!)

 

[Agentgonzo]

That, unfortunately, varies by yeast strain. And I have absolutely no idea.
Fortunately, there may be this information on file at Heriot Watt. My wife says "contact professor Susan Dewer"... or find someone on their brewing and distilling course (@DocAnna ) to ask the department on your behalf!

(Or someone may have a rough answer that is good enough!)

Oh... Or the same page of brew like a Monk says "Chris White of white labs estimates a good slurry will contain any 30 to 40% yeast by volume and should have about 1 billion cells per millilitre".

It also says accurate yeast counts require a £250 microscope...

 

[RoomWithABrew]

I think I'll just culture up a new starter of a few hundred ml and then put 3ml in each 750ml bottle with the Dextrose solution. Whatever happens it'll be carbonated after all as it's going in the bottle at 2.2 vols anyway.

I could just get the Haemocytometer slide and use the microscope in the lab here at work. It only gets used once a fortnight.

 

[Agentgonzo]

Ooooh, you have fun work toys!