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1 Guide To Yeast

2 Legal Notice No part of this ebook may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by an information storage and retrieval system with the exception of a reviewer who many quote brief passages in a review to be printed in a newspaper, magazine, or website without written permission from the publisher. For information, contact Alpen Publishing Company, 2506 N. Clark St #284, Chicago, IL This e-book does not provide you with official scientific information or official state and federal laws and policies regarding the production of alcohol in homes for personal consumption. If you want to know the official laws regarding homebrewing in your state, please contact your official state representatives Alpen Publishing Company & LotsOfHead.com All rights reserved

3 What is yeast? There are many different types of yeast, and the particular variety used by brewers is actually referred to as brewer s yeast and is a type of fungus. Yeast is a living thing, which means if you mistreat it, you can kill it. But if you take good care of it, it will take care of you by producing a healthy and thorough fermentation.

4 Fermentation 101 In the Introduction To Homebrewing guide I introduced the following: The basic brewing formula Yeast + Sugar + Water + Hops = Beer This at a high-level describes fermentation. Yeast consumes the sugars in our sweet wort, and the byproducts they produce are carbon dioxide and alcohol. Types of Yeast For brewers, we can split yeasts into two different categories: ale yeast and lager yeast. Ale Yeast Often referred to as top-fermenting yeast because much of the active fermentation takes place near the top of the liquid/wort in the fermenter. Ale yeast is much more active than lager yeast and capable of very vigorous fermentation, producing lots of carbon dioxide and resulting a large head of krausen or foam. Ale yeast performs best at warmer temperatures, usually from 55 F all the way up to 80 F or so. Ale yeasts also are known for producing more fruity or estery types of flavors, and the general rule of thumb is the warmer your fermentation temperatures, the more of these types of flavors are produced. Ale yeast also gets its work done very

5 quickly, with most fermentations taking anywhere from a few days to a couple of weeks. To be safe, most ale yeasts do just fine fermenting in the 65 F - 70 F range. Some extreme Belgian yeasts, used to ferment very strong fruity ales such as Tripels, are often allowed to ferment close to 80 F. Lager Yeast Lager yeast is often referred to as bottom-fermenting because it tends to do most of its work near the bottom of the fermenting tank. Lager yeast performs best at colder temperatures; 35 F - 55 F is a typical range for most styles of lager. While ale yeasts are known for crazier fruity flavors, lagers are known for crisp, clean flavors. If you really want the malt to do the talking in your beer, it doesn t get any better than a lager (think about the traditional German lagers such as Doppelbocks and Bavarian Helles). Because they work at colder temperatures, lagers take much longer to complete fermentation and to condition. You also don t typically see as much crazy activity and bubbling during fermentation as you do with ale yeasts. But even though you don t see much visual activity, slowly but surely, the yeast is doing its job.

6 Yeast Traits and Characteristics In order to differentiate between the many different strains of brewing yeast out there, the following qualities are used: Flocculation All brewing yeasts eventually clump together and collect into one large mass at the bottom of the fermenter once fermentation is complete. The faster a yeast does this, the higher its flocculation. This is important to know because yeasts high in flocculation often settle out before fermentation is completed, leaving behind lots of residual sugars resulting in a sweeter finish. However, if you brew using an appropriate yeast starter (as I always recommend), this is rarely a problem. Attenuation This is a description of how effectively the yeast converts the sugars to alcohol and carbon dioxide. Most values range between 67 77%, and this is referred to as its apparent attenuation. In theory, the higher the attenuation of the yeast, the more effective and thorough fermentation will be. However, there are many other factors that affect attenuation beyond the yeast s control (temperature, oxygen content, etc).

7 How much Yeast do I need? Great question with a complex answer. The amount of yeast required depends on a few different factors. The type of yeast, the starting gravity of the wort, and the fermentation temperature. The higher the starting gravity and the lower the fermentation temperature, the more yeast we need to produce a thorough and effective fermentation. The amount of yeast used is often referred to as the pitching rate. Basic Pitching Rate Formula (for ales): 1 billion cells per gallon of wort per 1 point (1.001) of gravity Using the above formula, if we have wort with a starting gravity of 1.050, we would need 50 billion yeast cells. If this beer was a lager that will be fermented at colder temperatures, we would want to increase the pitching rate to ensure good attenuation. A good rule of thumb is that pitching rates for lagers are double that of ales. For example, say we have 10 gallons of wort with a starting gravity of We split the wort into two different 5 gallon batches, fermenting one with lager yeast and the other with ale yeast. Using the pitching rate formula above, the ale will require 70 billion cells. Using the rule of thumb mentioned above, we should double that to 140 billion cells for the lager.

8 Most packaged yeasts contain anywhere between billion yeast cells. A number of factors such as how old the yeast is and what kinds of temperatures it s been exposed to can affect the true number of live cells in a package. You can get as particular as you d like when it comes to calculating the pitching rate for your batch of homebrew. If you want to keep things simple, I highly recommend making a 1 liter starter for ales under starting gravity, and a 2 liter starter for ales over starting gravity. I would double the starter size for lagers with similar gravities and have done this with good success (I brewed a Bavarian Helles and Oktoberfest lagers each using a 4 liter starter). If you do want to get really technical, the best free pitching rate calculator out there can be found here.

9 Why we make a yeast starter A yeast starter is a small batch of weak beer made for the purpose of increasing the yeast health and population before pitching into a full batch of wort. For example, we take a package of liquid yeast that has 70 billion yeast cells and make a small 2 liter batch of beer. After fermentation is complete, we will theoretically have at least twice as much healthy yeast as we started with. This in turn will result in a more efficient and faster fermentation, and better beer.

10 So which yeast do I use? Your best bet is to go with what the yeast manufacturers recommend for particular beer styles. If you re getting creative, take a look at the characteristics of the different yeast strains and decide which flavors you re looking for in your finished beer. Then, simply pick the yeast that matches what you re shooting for. Keep in mind there are reasons that certain types of porters are usually fermented with a certain type of yeast, and that most IPAs are fermented with another because brewers just like you have been experimenting with them for over a hundred years and have found what works best. That doesn t mean there s not a lot of room for creativity. For example, you can ferment a batch of beer with lager yeast at warmer ale temperatures (referred to as a steam beer, most famous example being Anchor Steam), or vice versa. You can try to ferment your coffee stout with a yeast traditionally used for German wheat beers. Who knows, maybe it will be great. The choice is yours!

11 Official Info from the yeast manufacturers Your best source for information on different yeast strains and their optimal use comes from the labs that produce it. Below you ll find links to helpful resources from the two biggest producers of homebrew yeast, Wyeast and White Labs. White Labs website: FAQ: Yeast Strain Guide (list of different types): Yeast Style Guide (common yeasts used for different beer styles): WYeast website: Yeast Strain Guide (list of different types): FAQ:

12 Equivalent Yeasts Sometimes you won t be able to get your hands on a particular type of yeast. Maybe your local homebrew shop only carries yeast from one lab, or a popular style has sold out online. In any case, the table on the following page shows you equivalent yeast strains from the different manufacturers so you can theoretically make substitutions and still brew a very similar beer.

13 For example, if a recipe calls for using White Labs WLP001 California Ale Yeast, but you can t find it anywhere, you d be okay substituting Wyeast 1056 American Ale Yeast. White Labs WLP001 California Ale Yeast WLP002 English Ale Yeast WLP003 German Ale II WLP004 Irish Ale Yeast WLP005 British Ale Yeast WLP007 Dry English Ale Yeast WLP011 European Ale Yeast WLP013 London Ale Yeast WLP023 Burton Ale Yeast WLP025 Southwold Ale Yeast WLP028 Edinburgh Scottish Ale Yeast WLP036 Düsseldorf Alt Yeast WLP051 California V Ale Yeast WLP300 Hefeweizen Ale Yeast WLP351 Bavarian Weizen Yeast WLP380 Hefeweizen IV Ale Yeast WLP400 BelgianWit Ale Yeast WLP500 Trappist Ale Yeast WLP530 Abbey Ale Yeast WLP540 Abbey IV Ale Yeast WLP550 Belgian Ale Yeast WLP565 Saison Ale Yeast WLP570 Belgian Golden Ale Yeast WLP720 Sweet Mead /Wine Yeast WLP800 Pilsner Lager Yeast WLP810 San Francisco Lager Yeast WLP820 Oktoberfest Lager Yeast WLP830 German Lager Yeast WLP833 German Bock Yeast WLP838 SouthernGerman Lager Yeast WLP840 American Pilsner Lager Yeast WLP920 Old Bavarian Lager Yeast Wyeast 1056 American Ale Yeast 1968 London ESB 2575PC Kolsch II 1084 Irish Ale Yeast 1187 Ringwood Ale Yeast 1098 Whitbread dry 1338 European Ale Yeast 1028 London Ale Yeast 1275 Thames Valley Ale Yeast 1335 British Ale Yeast II 1728 Scottish Ale Yeast 1007 German Ale 1272 American Ale YeastII 3068 Weihenstephan Weizen Yeast 3638 Bavarian Wheat Yeast 3333 GermanWheat Yeast 3944 Belgian Witbier Yeast 1214 Belgian Ale Yeast 3787 Trappist High Gravity 1762 Abbey II 3522 Belgian Ardennes 3724 Belgian Saison Yeast 1388 Belgian Strong Ale Yeast 3463 Forbidden Fruit Yeast 2001 Urquell 2112 California Lager Yeast 2206 Bavarian Lager Yeast 2124 Bohemian Lager Yeast 2487 Hella Bock 2308 Munich Lager Yeast 2007 Pilsen Lager Yeast 2247 European Lager Yeast

14 Storage Yeast should be kept refrigerated until used. Even then, you ll want to use it ASAP. If you order yeast online, be sure to pay the extra dollar and have it shipped along with an ice pack. This will help increase the chances that your yeast will survive the journey. Extra healthy yeast Yeast thrive in oxygen-rich environments, so the more oxygen you can get into your wort, the healthier your yeast will be. In the very least you should shake your fermenter vigorously for a few minutes after pitching the yeast to aerate the wort as much as possible. You can also purchase modified aquarium pumps with a filtration stone that pump air into the wort (most online homebrew shops sell these). If you really want to splurge, you can force oxygenate your wort using pressurized oxygen and a filtration stone.

15 Summary Take good care of your yeast and it will take good care of you. Be sure to keep it refrigerated until you re ready to brew. For the best results, I always recommend making a yeast starter and oxygenating or aerating your wort in some form.