Yeasts are living organisms, a uni-cellular fungus, and have a rare ability: to live with or without oxygen. In the presence of air, they multiply. In the absence of oxygen, they ferment sugars into alcohol. That’s what makes beer brewing possible.

Beer styles are distinguished by the two main types of yeast used to ferment the wort (the liquid made from water and malt, flavored with hops), to make ales or lagers.

Ale yeast is said to be ‘top-fermenting’ since the yeast cells tend to accumulate (‘flocculate’) at the top. Lager yeast migrates to the bottom of the tank during fermentation and so is called ‘bottom-fermenting’.

In the case of ale yeast, some interaction with oxygen takes place during fermentation. Ale yeast ferments quicker – a few days to two weeks – and at higher temperatures (around 21�C/70�F), though this can vary from as low as 10�C/50�F to as high as 25�C/77�F. Brews made from it also tend to store longer and have a higher alcohol content.

Lagers ferment more slowly (up to a month) and at lower temperatures, sometimes as low as near freezing. As a result, historically, lagers were often brewed in the winter and consumed later. Temperature ranges vary, though, and can easily be in the higher 45�F-59�F/7�C-15�C range. With modern refrigeration technology came the option of having lager year-round.

There’s also a third type, used originally almost exclusively in Belgium: Lambic yeast. The name derives from the West Flanders area in Belgium where the yeasts grow wild. Today, as a result of importing, it’s used in many parts of the world.

These helpful creatures transform malt sugar (maltose) into alcohol (ethanol) and carbon dioxide – the basic fermentation process. But, as its bread-making cousins do, yeast also adds distinctive flavors to the brew.

Many ale yeasts have a full-bodied, fruity aroma and taste. Others are more nutty or mineral tasting, suitable for stouts or Belgian ales and other strong brews.

One variety is used in Weizenbier, or wheat beer. The primary ingredient in beer is malt, from the cereal grain, barley. The name ‘wheat beer’ comes not from the grain used, but from the yeast used to ferment it. Wheat beer yeast goes into this ale-style brew, where it helps produce a fruity, intense character.

Lager yeasts are often smoother and dryer, with the taste of cloves, vanilla or a wide variety of other hints. Pilsner, for example, is a type originating in the Czech Republic in the town from which the brew gets its name.

Once, it formed the basis of 90% of the lagers consumed around the world. But with the growth of micro-breweries and the expansion of variety in the U.S. and elsewhere, lagers now come as Dortmunders, M�rzens, Bocks and other styles as well.

Though carbon dioxide and ethanol are the two primary products of fermentation, yeast produces secondary products as well. The different types can add tastes or aromas as varied as sweet corn to green apple to butterscotch. Unfortunately, they can also produce sulfur, or phenolics, which have a medicinal taste.

Control of the added flavor is as much an art as the control of fermentation is a science.

After all the equipment is prepared you’ll need ingredients for your home beer brewing.

Two and a half to three kilos (six or seven pounds) of malt extract will serve well. There’s an endless variety of types and brands and you’ll want to experiment.

A few dozen grams (a couple of ounces) of hops will be added to most recipes. Again, there are as many types and brands as there are sites devoted to brew making. Check some sites and experiment. Goldings and Fuggle are two popular brands. Don’t get sucked into the ‘whole is better than pellets’ debate at this stage. Either will do.

Two packets of dried brewers yeast. There may well be more types and brands of yeast than there are malt or hops. There are also liquid preparations, but wetting the yeast is part of the fun. Make sure not to pick up wine or bread yeast by mistake.

Step 1. Boil 18 liters (4.5 gallons) of water.

Step 2. Turn off the heat and mix in 2.4kg (5.25 lbs) of malt extract, until the powder is fully dissolved.

Step 3. Return the mixture to a boil and monitor to watch for boil-over. Lower the heat as needed. Boil for 15 minutes, then add 42 grams (1.5 ounces) of hops.

Step 4. Boil for another hour, then cool. Check to ensure the temperature is around 21°C-24°C (70-75°F). While waiting for the liquid to cool, wet the dried yeast with warm, sterile water.

Step 5. Stir the cooled wort clockwise and allow the hops to settle in the center, then siphon off the wort into the fermenter.

Step 6. Add wet yeast and stir vigorously. Extract a few milliliters (a couple of ounces) for measuring the specific gravity using the hydrometer. The numberdesired will vary around slightly over 1. Check the package. Then seal.

Now for the most important steps: fermentation!

Step 7. Between a few hours to a day, bubbles should appear in the airlock. Ifthere’s no sound and no sight of bubbles within a couple of days, your yeast is probably dead, but there are dozens of other possible causes. If you still don’t see any activity, wait a few days, then start over.

Step 8. Allow the wort to ferment for 5-7 days. The time will vary with recipe, with environment, yeast and several other variables. You’ll need to experiment. Don’t be too disappointed if you don’t get it perfect the first time.

Step 9. Siphon into the secondary fermenter, stored in an area several degrees cooler. 10°C/50°F is a good starting point. Cooler for lagers, warmer for ales. Allow to sit for another seven days.

Step 10. After fermentation, some recipes call for 120-175 ml (1/2 – 3/4 cup) cane sugar or corn sugar, though many consider this optional or even undesirable. Experiment to taste. Pour into bottling container then siphon off the top. Fill each bottle, leaving ample space near the top. Store 2-3 weeks at room temperature, then chill.

Now for the best part. Decant, serve and enjoy your very own beer.

As with any home project, preparation is half the key to success in home brewing. Everything should be clean and well organized so you can carry out the steps with confidence in the final result in your home brew. Home beer brewing equipment, and preparation include water, capper, and beer bottles to name a few below is a list of items, and steps to get you started.

But what is ‘everything’?

Water is a very important ingredient in the home beer brewing operation. You wouldn’t think water could vary so much, but this may well be the most varied chemical substance on earth. Of course, water is nothing but H2O, but the elements dissolved in it make a huge difference to the final product. 22-30 liters (six-eight gallons) of spring water is a good start, but you’ll want to experiment.

You can make beer without some kind of grain in the home beer brewing operation we call this Malt. This is the basic material that gets transformed into beer. Usually it’s some kind of barley grain. Obtain online or from a local store.

Home beer brewing would take forever, or just not happen with yeast. These live organisms turn the sugars into carbon dioxide (the bubbles) and alcohol. Thank them for their fine efforts.

Everyone has seen the giant brew kettles the breweries use, now you need one more your size for your home beer brewing operation. This container will store unfermented liquid (‘wort’) to be boiled. Often a five-gallon glass carboy (like a large water bottle) is used. Hops and other ingredients are added through the spout at the top.

Fermenter is a fancy name for a 5 gallon bucket with a lid in the home brewing operation.  A container with a lid, it will be used to hold the cooled wort. Yeast will be added to carry-out the fermenting process. Two are required if secondary fermentation is part of the recipe.

Another word for a bottling tank in a home beer brewing operation is another clean 5 gallon bucket.  You’ll siphon the fermented beer into a container before bottling. Like all the equipment, it’s essential that this be completely clean.

What is the point of brewing beer if you can’t bottle it?  Every home brewing operations requires beer bottles.  You’ll need clean beer bottles for storing the final product (assuming you and your friends don’t drink five gallons of beer right out of the tank). Dark brown bottles are best, to keep beer from being spoiled by light during storage.

Home brewing requires a Bottle filler: A spring-loaded device used to fill the bottle when the end is pressed. Available, as is the other equipment, from any of dozens of home brew kit sales sites online.

You might want to think about purchasing a Capper for your home beer brewing operation. Optional, but helpful, to put caps onto the bottles. Corks or screw tops are alternatives, but each has drawbacks. Cork can splinter or introduce moldinto the brew. Screw tops need to be seated properly in order to ensure a tight seal to avoid oxygen spoilage.

Miscellaneous items you might require when you are home brewing. A thermometer is essential to check the temperature at various stages. A hydrometer is helpful, to measure something called ‘specific gravity’. SG is a measure of the density of some material relative to water. Not critical but extremely helpful. Various siphon tubes, copper and/or glass and/or hard plastic. A timer with a loud bell or buzzer, so you don’t forget those time critical moments.

Sometimes the copper tubing is formed into a wort chiller. Formed in a spiral around the tank, cold water flows through to draw heat away from the boiled wort. Helpful, not essential for many recipes.

Heat source: You’ll need a method for boiling and cooling. Air will often takecare of the cooling need. Heating can be carried out by a dozen different methods, usually some kind of Bunsen burners or electric heating coils.

The equipment should be cleaned, and many recommend sterilization with a dilute bleach followed by rinsing in boiling water. At least part of the environment should be able to be kept cool, below 13°C (55°F) for part of the time.

Be prepared to spend a few hours on two different days, with activity off and on. Two people are often helpful to carry out certain steps.

What steps…? We discuss that in Part II.