Using Mr Malty

[mattybabsy]

Folks

Cultivating yeast from bottles of Chimay red and Westmalle tripel for the first time. Everything is going well- they're in around 500 ml of wort each and have started nicely. My question is how much do I need for my batches? What size of starter do I need to grow them to?

the relevant figures for my tripel recipe, atm, is og 1.081, making 23 litres.

In this example, what production date do I put? Do I do it as a liquid yeast, or repitch from slurry? ale, hybrid or lager?

i've been intermittently shaking it

thanks

matthew

 

[johnnyboy1965]

The "recommended" pitching volume is 1500ml-2000ml per 23 li.

 

[johnnyboy1965]

Are you using two different types of yeast ?

 

[mattybabsy]

hi jonny- thx for replying. no, doing 2 diff beers with their own single yeasts in each

how did you get those figures?

 

[johnnyboy1965]

It took me some time to get my head around pitching rates. Because we dont have the capabilty to count yeast cells, itis worked out on volume. Basically if you make up your starter to 1.5li-2.0li at a gravity of 1.040 then by the time the starter has fully fermented out you will have so many million yeast cells. This is the correct ammount to pitch.
HTH Johnnyboy

 

[mattybabsy]

does it not depend on how big the beer is going to be? surely a 1.5- 2 l starter at 1040 will be too much for some beers and not enugh yeast for others?

 

[johnnyboy1965]

By "big" do you mean Volume or Strength ?

 

[mattybabsy]

sorry, strength

 

[johnnyboy1965]

Thats down to the strain of yeast. Different yeasts have a different viability. If your using a harvested yeast from a bottle go on the strength of the beer from the bottle. If you want a higher SG then go for a yeast designed for that

 

[mattybabsy]

I know diff strains ferment diff strengths of wort, but how do I know how much of the starter I need? The amount you gave, 1.5-2L, are you saying that's the correct amount of starter to pitch for any beer, no matter how strong it is? How did you calculate that amount?

 

[johnnyboy1965]

I read the ammount somehere (cant remember where) but I think its a "standard. If your intened brew has a SG of 1.080 then your starter wants to be the same, still to a volume of 1.5li - 2li. This will insure that your yeast is capable of handling the higher gravity.

 

[mattybabsy]

eh, not sure that's right. if the starter is that big then the yeast will be stressed by the time they're pitched, thus defeating the point of using a starter. From what I understand, a starter from a bottle cultivated yeast is for 2 reasons- to make sure the yeast is still alive and to help grow the cells to the appropriate amount.

 

[graysalchemy]

I wouldn't make your starter up to 1080 the yeast will be F*cked before it has started, you should never reuse a yeast from a strong beer as it will be stressed. Have you looked at the how to on culturing yeast here.

If you are doing a strong beer then you need to pitch a lot of yeast, some people will brew a standard bitter then use the yeast cake for the strong beer. I had a barley wine last year 30L and I used 2l of slurry from a 1050 bitter, it went like a rocket. :thumb:

 

[johnnyboy1965]

The reason of making up a starter to 1.080 (matching your brew) is to make sure that the yeast is capable of working at this gravity. If you make up a starter to 1.040 and the yeast can only cope with, for instance 1.060, when you come to pitch the yeast will have little chance.

 

[mattybabsy]

thanks gray. I'm not too worried about the yeast being too stressed.- afaik the trappist yeasts are added fresh at bottling and have only carbonated the beer- is this not less stress on the yeast than if they had actually fermented the beer?

How much yeast is 'a lot'? The starter if going well, I'm just not sure what volume I want to aim for eventually as I increase the size of starter

 

[graysalchemy]

thanks gray. I'm not too worried about the yeast being too stressed.- afaik the trappist yeasts are added fresh at bottling and have only carbonated the beer- is this not less stress on the yeast than if they had actually fermented the beer?

How much yeast is 'a lot'? The starter if going well, I'm just not sure what volume I want to aim for eventually as I increase the size of starter

Yeast is stressed most during the initial growth phases so if you pitch a small volume of yeast into a high gravity beer it goes mad gets stressed and doesn't do its job properly, If you grow it in a lower gravity you will get more less stressed yeast which when you pitch into a higher gravity has more of a chance of doing what it is meant to do. Stress you yeast and you will send it down different metabolic pathways. :nono: :nono:

When you are pitching fresh yeast just to carbonate you don't actually need much metabolism to produce the amount of co2, needed also at the quantity pitched it isn't going to affect the flavour as all the flavour has been produced.

As I have said either use a yeast cake or pitch up the yeast from about a starter made to about 4L but drain of the resulting beer just pitch the yeast. As a point of interest if you were to use packets i would use 2-3 for a 23l brew not the normal 1. :thumb:

 

[johnnyboy1965]

Stressing yeast is a contributing factor in badly produced beer. Im not saying your beer is badly made.
Yeast health is mostly overlooked in HB, and IMHO shouldnt be. Your about to add a living organism to your beer, the heathier that yeast is the better.

 

[mattybabsy]

thanks gray- 4 L was what I had in mind, but was wanting to use mrmalty to confirm my thoughts- just couldnt work out how to use it.

i think ill stick with the 4l plan then- the wort is about 1030, so should be good to go

thanks again

 

[johnnyboy1965]

Have a look at John Palmers www.howtobrew.com.
Chapter 6.6
He explains it better that I can

 

[mattybabsy]

jonny- that's only if you pitch at or near peak activity. I wasn't planning on doing that.