Yeast is blowing my mind!!

[Piperbrew]

As the title says, yeast really is blowing my mind!

I have gone to the trouble of making myself a stir plate and just ordered Wyeast for the 3 beers I intend to make, but how the hell do I calculate the yeast that is required. I have had folk kindly help but I still cannot fathom it.
I know there are calculators but for example how can you input the numbers if you haven't brewed a beer before and don't know the hydrometer readings, bearing in mind your making the starter a few days in advance.

Also if your making a starter from one sachet of yeast how do you know when it is big enough for the beer you are planning to make. I am guessing to much is possibly as bad as too little yeast when pitching.
Does it go on how much volume in mls you have in the flask of DME

And does anybody harvest the yeast off the beer and harvest and freeze.

Please feel free to think I am being dumb as I feel it at the moment..

 

[Martybhoy]

I use Brewers Friend yeast pitching calculator, it's free.

You need to know the age of your sachet of yeast, the intended starting gravity of your wort, and the intended volume of wort you'll be fermenting (your recipe will tell you these).

The calculator will give you the number of cells in your yeast sachet (based on its age) and the number of yeast cells required for pitching. You will almost certainly be short, and therefore need to make a starter.

The calculator then gives you the option of working out how big a starter you need to make, at a 10:1 ratio (1ltr of water would require 100gms DME, 1.5ltrs would require 150gms and so on).

Give it a try and come back if you have any questions.

As for making enough yeast for 2 or 3 beers, you can either harvest the yeast off your fermented wort, or make a big enough starter first time round for multiple beers.

 

[BarnBrian]

Hi PB
Do you not think you're trying to get Olympic Gold before you've run to catch the bus. Start off simple and then refine the different processes over time. Make at least a dozen straightforward brews and smell, taste, observe and record.
Good luck with the brewing.

Brian:thumb:

 

[Piperbrew]

Hi PB
Do you not think you're trying to get Olympic Gold before you've run to catch the bus. Start off simple and then refine the different processes over time. Make at least a dozen straightforward brews and smell, taste, observe and record.
Good luck with the brewing.

Brian:thumb:

Fair point Brian :thumb:

 

[MyQul]

It's actually fairly simple if your using a Wyeast pack as the cell count is known

Then like martyhoy says use a calculator to input the date of the pack, your brew OG and any other pertinent info. The calculator will then tell you whether you've got enough cells or whether you need to do a step up.

I like this calc, http://www.brewunited.com/yeast_calculator.php . It also has an 'overbuild' facility so you can make the starter bigger than you need and portion some off to use to make your next starter

 

[BeerCat]

It depends how fresh the yeast is. I bought some recently only a month old and they went off like rocket. If its just for 1 batch i just reserve a little bit in a small bottle for next time. If its a Lager i build it up twice. Dont worry about those calcs just enjoy brewing.

 

[Piperbrew]

It's actually fairly simple if your using a Wyeast pack as the cell count is known

Then like martyhoy says use a calculator to input the date of the pack, your brew OG and any other pertinent info. The calculator will then tell you whether you've got enough cells or whether you need to do a step up.

I like this calc, http://www.brewunited.com/yeast_calculator.php . It also has an 'overbuild' facility so you can make the starter bigger than you need and portion some off to use to make your next starter

I think the part that I am confused about is how do you know the quantity that is in the flask. I know you put X amount DME in but once the yeast has done its work in the flask do you measure the depth of the yeast cells?

Also if your making a starter a few days before how do you know what gravity to input if its a beer you have not made before....are there generic gravities for different type of beers?

Also is too much yeast ever harmful to a beer?

Oh and I asked my local brewery for some of their yeast today incase I do a clone beer. They were great and said pop in and they will have a pack ready for me.

Edit..I just looked at that link and a bit clearer now as it told me the amount of liquid/DME.

 

[foxbat]

I think the part that I am confused about is how do you know the quantity that is in the flask. I know you put X amount DME in but once the yeast has done its work in the flask do you measure the depth of the yeast cells?

When it's done it's done. You just have to trust that the calculator got its numbers right. A lot of the stuff involved in building these starters is based on vague numbers and hand-wavey predictions. They do seem to work though.

Also if your making a starter a few days before how do you know what gravity to input if its a beer you have not made before....are there generic gravities for different type of beers?

Input the predicted SG from your recipe software. A few points off either way won't make a difference.

Also is too much yeast ever harmful to a beer?

Not harmful but there are those that say you can change the flavour outcome by over or underpitching. It seems to be a popular technique with those that brew Hefeweizens for example.

Oh and I asked my local brewery for some of their yeast today incase I do a clone beer. They were great and said pop in and they will have a pack ready for me.

Nice guys, snap that one up!

 

[Piperbrew]

When it's done it's done. You just have to trust that the calculator got its numbers right. A lot of the stuff involved in building these starters is based on vague numbers and hand-wavey predictions. They do seem to work though.

Input the predicted SG from your recipe software. A few points off either way won't make a difference.

Not harmful but there are those that say you can change the flavour outcome by over or underpitching. It seems to be a popular technique with those that brew Hefeweizens for example.

Nice guys, snap that one up!

Thanks for your reply and all the others. Finally it all makes sense, I just wanted to clear those points up as didn't want to mess a beer up as if I do manage to mess one up understanding all the parts of the process means I can work my way backwards and find out what I did wrong. Hopefully it wont go wrong.