Yeast – Much More Than a Microorganism with a Sweet Tooth

I recently started reading Yeast: The Practical Guide to Beer Fermentation by Chris White & Jamil Zainasheff to get a better understanding of Yeast. I had read some basic information in the past, but it wasn’t until I started reading this book that I have began to understand the imperative importance of yeast in the brewing process.

It goes much deeper than just “yeast eats sugar and makes alcohol” which, although a bit dumbed down, was my basic understanding before.

Looking back now at times when I brewed beer from kits, as well as my recent extract brew experience, I didn’t choose in the right way. It was based – I’m afraid to say – on what was cheapest. Don’t worry (I could see the worry on your face) I will no longer use price as a way of choosing a strain in the future.

Anyway, as I have been working my way through the book I have been taking notes, which I’ve decided to put up on this blog as a way to document my growing understanding of these tiny, but hugely vital microorganisms.

Only 55 pages in, but here is what I’ve learned so far.

Very Quick History

Although yeast had been observed in the past – under the microscope around 1680 – it wasn’t until the mid-1800s that Louis Pasteur established that yeast was a living micro-organism  Previous to this, it was believed that yeast was simply a by-product of fermentation. Pasteur experimented for many years with various yeast cultures and sugars to better understand what made it tick. 

One of the 1st breweries to adopt his ideas was Carlsberg. Under Emil Christian Hansen the brewery’s lab managed to isolate the 1st Lager strain of yeast – Saccharomyces uvarum (today known as S. pastorianus).

Due to the fact that Lager yeast has specifically used and therefore well cared for, with the brewers understanding what to expect from it, lager became clearer, more consistent and gained a longer shelf life. Ale production was not as sophisticated with wild yeast and bacteria problems common place. This led to a rise in lager drinking, over Ale.

Very Brief Overview

  • Yeast is a part of the fungus family and is a single cell organism.
  • There are over 500 species of yeast – each with thousands of strains.
  • Yeast coverts sugar into alcohol, CO2 and other compounds that influence the taste and texture of fermented food and drinks.
  • Different strains of yeast produce different flavours and characteristics. Knowing what different strains of yeast produce – in terms of aroma, flavour, etc – goes a long way to producing beer that matches your intended vision.
  • Yeast requires nutrients to improve and/or maintain good health and performance.
  • Temperature control is essential for consistent beer. If there is a problem – and contamination can be ruled out – the majority of the time the issue will be temperature related.
  • There are two main species of yeast favoured for the brewing of beer:
    • S.Cerevisiae (ale yeast)
    • S.Pastorianus (lager yeast)

Next up in the book is the section on how to choose the right yeast for your beer. This is something I’m quite interested in, so once read and digested the information  I’ll no doubt write-up a post about what I learn.

Categories: Brewing Information | Tags: , | 1 Comment

Post navigation

One thought on “Yeast – Much More Than a Microorganism with a Sweet Tooth

  1. Pingback: How To Homebrew Beer: Temperature | Bard's Home Brew Brewery

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Create a free website or blog at

Jan Harding

Artist in my Spare Time...


The proof is in the drinking

The Apartment Homebrewer

Brewing small batches of craft beer in a 650 sqft apartment

Bier Battered [.] com

Cheesey Movies & Craft Beer Pairings, brews from New Jersey and beyond

We make home brew

A blog about tasty home brew and beer.

It's that Craig Heap guy

A Welsh Beer Blogger celebrating the great ales of Wales

Blogging at World of Beer

the temporary home of Stephen Beaumont's World of Beer

Oh Good Ale

Phil's beer blog

Tim Hampson's Beer Blog

The quest for the perfect beer

The Great Canadian Beer Snob

Your guide to the wonderful world of beer!

The Mostly Harmless Brewing Co.

Homebrewing in The ATL


'Zee-tho-fyle', by Martyn Cornell, an award-winning blog about beer now and then, founded in 2007

sounds like beer

Beer & Music. Nothing Else Matters

I Think About Beer

& I Think About Cider - Belgian Beer & European Cider

The BeerCast

Scotland's beer website

The Good Stuff

Good Food. Good Beer. Good People.


Brewer with a Brewery Problem. Tui, Fyne Ales, Thornbridge, Epic, Good George, Brew Mountain and Fork & Brewer.

Jotham Brewing

the musings of an amateur home brewer

The Beer Nerd

A Diary Written With Beer

Alebagger's Beer Blog

Alebagger's exploration of the world of ale, pubs, brewing and all things beery.

Beers are a Changin

Exploring the best craft beers and brewers in Australia


Beersay - unverified, unofficial information gained or acquired from various sources or sauces about beer.....probably


Multi award-winning beer writer and author

Alcohol And Aphorisms

Whisky and Beer Discussion In A Relaxed, Yet Slightly Pretentious Fashion

Good Beer Better Hats

Our Hats are Off to You! ~Cheers~

Barley's Homebrewing Supplies

101-455 East Columbia St, New Westminster, B.C. 604.553.1941


A detailed blog following my homebrew and craft beer endeavors

Jay's Brewing Blog

Tips, tricks, hacks and more for everyting you need to make great beer, wine and mead.

Chris Hall | Beer

Craft. People. Places. Stories. Culture.

Craft Beer Reviews & Commentary by HomeBrewedHero

4 out of 5 dentists recommend this site


Beer brewing in Leeds

Chop & Brew

A blog and webshow highlighting life's great food and fermentations

Apuhihi View

Thoughts from a previous coast (Mostly about my home-brew adventures)

Learning to Craft Beer

Making craft beer is one of the best hobbies ever. Let's talk about it. is the best place for your personal blog or business site.

%d bloggers like this: