Today, we’re at the last two ingredients used in beer.  Both of which are more complex than any of the ingredients we’ve talked about so far.  That’s right, now it’s time to talk about water and yeast.

Water is usually the last thing most homebrewers start researching, which is somewhat strange since 90% of beer is water.  Water chemistry is why there are different styles of beers associated with different regions. The water sources used in those historic breweries were well suited for specific beer styles.  The brewers may not have understood the water chemistry, but they knew which beers tasted better when they made them. One of the most important of these towns is Burton-on-Trent and you can buy Burton salts to this day to adjust the chemistry of your brewing water.

Most of the larger commercial breweries today will user reverse osmosis filters to make a neutral water, then adjust the water to what they want with additions.  Homebrewers do have the option to do this as well, but it increases costs, and prep time. If you want more visibility into what your tap water has in it, you can either contact your municipal water department, or ask at your local homebrew shop.  If you’re on a well or other water source, you may need to spring for the water test yourself.

If you want to start making changes to your brewing water, Bru’n Water is a highly regarded site and source.  Be warned, it’s a deep subject and it can be really easy to get into the weeds here.  Another option is to brew a variety of styles, and see which ones you’re happy with and focus on them.  Then work on adjusting the water chemistry to better match the styles that you’re not happy with the results of.

Yeast is the other dark art ingredient.  There’s an old saying in the brewing world that brewers make wort, yeast makes beer.  You’ve spent time and money to make this wort, and now you throw a living organism in there to spoil it in a very specific way.  While I named this series Enslaving Yeast, really you’re going to be building an all expense paid, luxury resort for the yeast and throwing them in.

There’s two major families of yeast strains used in brewing: Ale, and Lager.  In general, Ale yeasts (top fermenting) can tolerate higher temperatures, and will produce more flavor notes.  Lager yeasts (bottom fermenting) need a lower fermentation temperature, and will generally be a slower ferment.

The key to a good fermentation is healthy yeast.  The key to healthy yeast is making sure the proper nutrients are there, you pitch the correct amount of yeast, and the yeast is healthy to begin with.  One of the easier ways to do this is with a pitch rate calculator.  This will estimate how many healthy yeast cells you’re throwing into your wort, and how many you’ll need for a good clean fermentation.  The reason you want healthy yeast is to make sure they reproduce faster then wild yeast or bacteria, and you get the flavor profile you want.

Another option is to make a starter (which you can also use to make extra yeast to set aside for a later batch).  To make a starter, mix up some fermentables (DME is the preferred one here) with water in a ½ to 1 gallon jug (or flask if you want to look fancy), put on an airlock, and shake it up on a regular basis.  You can also buy (or build) a stir plate to keep the yeast agitated for the day or so it will take for them to propagate enough. Then you can cold crash the starter, pour off the liquid (which would technically be a very flavorless beer), and pitch (or save) the yeast.

If you want to harvest yeast from a commercial source, save some dregs of a bottle conditioned beer, and pitch those into a small starter.  Step that starter up a couple of times (say from 16 oz. to 32 oz. to 64 oz.) and you’ll have a viable amount of yeast to pitch. Keep in mind your sanitation here, and some brewers do use different strains of yeast to bottle condition their beers then they do to ferment them.  There’s quite a few threads around on the homebrewing forums talking about who uses what.  I’ll say that I detected no difference between the Saison DuPont yeast and the WLP565 in a batch I made.  Also, that if you go with Ommegang yeast, it ferments hard and fast… use a blow off tube.  Harvesting dregs is also one of the few ways you can attempt to culture some items such as the lambic blends (for sour beers).

The last thing you’ll want for your yeast is a stable temperature range in their preferred temperature range.  Different yeasts have different preferences, and they will generate heat themselves as they go through the fermentation process.  While temperature control is generally believed to be really important, as long as you have stable temperatures, you’ll generally be able to make good beer (so don’t put it next to a heating/AC vent).

That’s the ingredients, next we’ll go through the mash.  The only difference between all grain brewing and extract brewing.