Friday, 17 February 2012

Yeast Additions

An article from Barry

For a lot of home brewers, yeast addition is a bit of a mystery.


Should I add 1 packet or 2, should I make a starter (and how big should this be?), how much slurry from a previous batch should I use? These are all questions that we all ask from time to time.


Well here is a great little web site to help you calculate out how much yeast to pitch into your brew,
www.mrmalty.com. It is a calculator created by Jamil Zainasheff, and there is also a iPhone app available for a few dollars (web site is free though).

You simply select the type of beer you are making (in this case a Helles Bock with an OG of 1.072) , type in the OG and the volume of wort you want to ferment and presto, you now are told you need to get a bank loan to buy 6.2 Wyeast activator packs, as you need 602 billion active yeast cells. That option is not very inviting, so what other options do we have.
  





















You are also given the alternative of making a “small” 10.14 litre starter, using 2 smack packs (100 billion yeast cells each).

Switching to the Dry Yeast tab, you will see that you need 33 grams of dry yeast, or 6.7 of the 5 gram sachets (ouch another bank loan required).



Finally, if you look at the “repitching from Slurry” tab, you find that you can get the required 602 billion yeast cells from 265 mls of yeast slurry, if the slurry is half way between thin and thick (very scientific measurement required here – call in the
experts).
So, an economical way to get your yeast for your Helles Bock is to get the yeast slurry from the Munich Helles you are brewing now for the February comp and you can save yourself a call to the bank manager.





I have set the preferences on the preference tab as seen below. The web site
defaults to US Gallons, but remembers your preferences.


4 comments:

Jethro and Millie said...

hi guys

yummybeer said...

we are viral!

AndyMac said...

Very handy. Now I just need to learn how to do starters.

TroyP42 said...

Great article Barry.

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