Let's talk about yeast.

For a blog that's all about yeasty goodness, there hasn't been a whole lot of talk about yeast.

So, let's talk about yeast.

Baking yeast is interesting enough, but I can't say that I'm very deep into it at the moment so let's talk about brewer's yeast.

Beer making is simple enough at first glance. It's water, hops, malt and yeast. What does yeast do?

Simply, it makes carbon dioxide and ethanol as two of its important by-products. The carbon dioxide is what gives us the bubbles in our beer and the ethanol is the alcoholic goodness which we all know and love. There are other by-products but they're beyond the scope of this post.

In brewing, yeast goes through a couple of major stages. The first stage is where is consumes as much of the oxygen present in the wort so that it can reproduce. When the oxygen runs out, the yeast commences producing alcohol.

There are literally thousands of yeasts from many suppliers that are used in hand made beer and commercial beer alike. Some for the hobbyist are close copies of famous commercial yeasts used in your favourite off the shelf beer. Some are the real yeast used by your favourite brewery.

There are two main groups of yeasts:

• Dry
• Liquid.

Dry yeasts are made by a spray drying process, among others. Basically a solution of live yeast is made at the factory, which is then sprayed as fine droplets and dried by a variety of processes. The dried yeast is then coated in a nutrient or other material to ensure freshness and then packed into individual sealed foil pouches.

Liquid yeast on the other hand is the liquid from which the dried yeast is made. "What's the difference?" you ask.

The difference is that the dry yeast is more stable over a longer period of storage and can tolerate a reasonable amount of mishandling and still produce a good result. Ideally, if they are kept in the fridge and then warmed up to room temperature a few hours before use you will have a good result.

Liquid yeasts need to be temperature controlled (cool) in order to keep the yeast alive and have a shorter 'use by date' of about six months from when they leave the factory. These liquid yeasts come in a variety of packaging, but the most common is the plastic screw-top vial, much like this one:

Similarly, liquid yeasts need to be warmed to room temperature before use. Check the manufacturer's instructions on the pack.

The other difference is price. A packet of dry yeast is about $4 - $5. A vial of liquid yeast is about $15 - 18. Worth it? I say yes.


If you buy kit beer, it usually comes with a package of yeast under the lid. For all intents and purposes, it's OK but it won't give you the best beery result for a variety of reasons. If the kit is from a reputable maker such as Coopers (http://www.coopers.com.au/homebrew) or Morgans (http://www.morgansbrewing.com.au/products.asp?range=Overview), chances are that the yeast which it came with is pretty good, but through non-optimal handling it may not be in the best condition to give you a top grade result. They're good yeasts and able to withstand the kind of abuse someone new to brewing can dish out, purely through not knowing enough. In the hands of an experienced brewer they can be used to produce a rather pleasant every-day beer.

You've put your money on the table, bought your kit and bits or taken that next step to all-malt extract brewing and want to make your result shine. After all, by this stage you're after quality and not just a buzz. The buzz is a nice side effect.

That's where after-market yeasts come into play.

The most common stepping stone from the original kit yeast is to one of the Fermentis dry packet yeasts. A couple of the most popular are S-04 and S-05.

S-04 is styled after an English ale yeast. It produces a lovely result with some residual sweetness, much like a real English Ale such as a Best Bitter or a Special Bitter and the like. It tends to enhance the malt aspects of the flavour profile. It's really easy to use and very reliable and economical. I'll tell you something to make it even more economical a little later in this article.

S-05 is an American style yeast, producing a result that is more dry and tends to make the hops a little brighter and more forward in the flavour profile. Great for making something like the famous Anchor Steam Beer and similar.

Dry packet yeasts are very easy to use and rather predictable in how they do what they do. You can either just sprinkle them into the wort and let them do their thing or you can rehydrate and feed them a little to get the action started a little sooner.

Naturally enough, Fermentis has a massive range of yeasts which are suited to a very diverse range of applications and therefore flavour profiles, fermentation characteristics and more. We can get more into what kind of yeast does what in another article.

If you want to go a little further in quality, then it's liquid yeast time for you. I'm certainly not going to go through the White Labs or Wyeast list with you one by one - I'm just going to mention a couple which I have used and found interesting and that give a great result.

My new favourite for making English ales is WLP002 English Ale Yeast. There are some others for making English ales from White Labs which have slightly different characters. However, WLP002 is a good starting point. It's an aggressively flocculating yeast. This means that it clings together and drops out of solution very quickly when it has nothing to do, or starts to feel lazy. To get around this, you need to give the fermenter a rock just to get it off the bottom and keep it doing its good work. The end result is a beer that looks rather clear, almost like commercial filtered product and has a truly traditional flavour.

Another one which caught my eye and I used for my 'Froehlichen Kirschenbier' (Cheery Cherry beer) is WLP550 Belgian Ale Yeast. I had been buying various Belgian beers at local shops at up to $9 for a 300 to 330 ml bottle - far too expensive to enjoy a few every evening. This yeast was the solution to that problem and wow did it deliver! It's a rather highly attenuating yeast. In other words, if you start out with a high specific gravity it will finish with a low specific gravity. It takes about ten days to ferment at around 18C, but it's certainly worth it. I hear that a little extra heat towards the end of the fermentation, say 22C, helps bring out some of that Belgian funky character to make a truly distinguished and authentic drop. Highly recommended.

One of the other gents I know who brews is a huge fan of Nottingham Ale Yeast (available as WLP039 from White Labs) . He tells me that it's a very fast fermenting and aggressive yeast. Some yeasts politely stay in the fermenter and do their work. Notto goes mad and works hot, up to four or five degrees celcius above ambient temperature. If you're into ESB then this is the beastie you need.

Take a look around the Fermentis site (http://www.fermentis.com) and White Labs site (http://www.whitelabs.com) for more information and to see their outstanding ranges of yeast.


Here's the hot tip I promised earlier: How to make yeast costs lower.

• Choose a yeast and ferment as usual.
• Bottle or keg as usual, leaving the yeast cake in the bottom of the fermenter.
• Collect a cup of yeast in a sanitised container.
• Add around 300 ml of water at around 27C and about 10 - 20 grams of sugar (I prefer dextrose, but others are OK)
• Stir well with a sanitised spoon.
• Cover with cling wrap.
• Prepare your next wort, clean your fermenter.
• Wort into the fermenter, dilute to volume.
• Measure OG.
• Add the yeast which you've collected, fed and watered.
• Stir powerfully to get as much air into the wort as possible.
• Ferment as normal.

You can do this about five or six times before the yeast ceases to be viable or begins to cause problems.
There are more advanced yeast farming techniques but I won't go into those at this time. This is the quickest, easiest, least expensive and least equipment intensive method to get more value for your yeast money.

Happy Brewing!