Yeast! The magical... fungi?

Yeasts are a fungi with 1,500 different species. One species in particular, Saccharomyces cerevisiae, has been used for thousands of years in baking and alcoholic beverages. Through the process of fermentation, carbohydrates (starches or sugars) are converted into alcohols and carbon dioxide. Carbon dioxide is what makes bread leaven by creating air pockets in the dough, carbon dioxide gas is also used to create...Pop Rocks! The alcohol is the product of yeast that is important in beer. However, the spent yeast itself lends a flavor and aroma to beer.

Bread leavened by carbon dioxide from yeast

Brewing yeasts can be classified as "top-fermenting" or "bottom-fermenting." Top fermenting yeasts got their name because they produce a foam at the top of the wort (liquid extracted from mashing) during fermentation. Dependant on the style of beer you are producing, you may decide to purchase a certain strain of yeast. Top fermenting yeasts are used in brewing porters, ales, stouts and more. Bottom fermenting yeasts are used in pilsners, bocks and more. Other than the carbon dioxide and alcohol that yeast produces, it can also leave behind other flavors and aromas such as butterscotch, sulfur, or green apple. Learn more about top and bottom fermenting yeasts and yeast flavors.

Head (foam) of a beer

Yeast can be purchased in many different forms: liquid, pressed, crumbled, active dried, and instant dried. When I used to work making fresh pizza dough in a restaurant, we would always use pressed yeast because it was shipped in blocks and the proper amount (1/2 a brick) could easily be thrown into the mixing bowl. Click to learn more about these different forms of yeast.

Any cereal (edible component of grain) containing sugars can undergo fermentation due to wild yeasts in the air. As far back as 7000BC, Chinese villagers were producing alcoholic drinks. Beer was part of the daily diet of Egyptian Pharaohs over 5,000 years ago, it was made from baked barley bread and was used in religious practices as well. Tutankhamum Ale is limited edition beer has a very interesting past. It was brewed in the basement of the laboratory of Cambridge from a recipe that was discovered at Queen Nefertiti’s temple in Egypt. Average retail for this beer is $52 per bottle. Learn more here!

Tutankhamum Ale

Certain yeasts can be used in microbial fuel cells, and other types are pathogens that can cause infections in humans.  Yeast cells are also used to do genetic studies, as they have similar features to human calls. They can be engineered to produce proteins which can be used to treat human disease. Yeast is often taken as a vitamin supplement because it is 50% protein and a rich source of B vitamins. Yeast sure is a magical fungi!

When brewing beer, have you ever used liquid yeast? We Want to hear from you

Malts: The Grains of Paradise

In order to understand the brewing process, you first have to understand the ingredients that go in to making beer. Over these couple of posts, I will be discussing in short what each ingredient does to a beer. Now, we already covered hops. They are what gives beer it's bitterness and citrusy/floral aroma. This week, we are moving over to malt, the ingredient that really gives beer almost every essential characteristic that determines just what style the beer is.

icture Showing Different Range of Malts

Malts are the ingredient in beer that balances out the bitterness that hops give. They create the sugars that are essential in giving the beer it's alcohol content and carbonation. The malts also give the beer it's color. The lighter the beer, the less amount of time that the malts were put into a kiln or dried. The darker the beer, the longer the malts have been roasted or kilned. Without malts, beer would be so bitter that it would be impossible to enjoy. Not only that, it would most likely always be green and would not have the visual and taste characteristics that it has.

Malts give beer it's color and sweetness.

Malting actually defines a process in which grains, like barley and wheat, are taken and brought to a state that forces them to release the starches and sugars that are essential in the fermentation of beer. What happens in the process of malting is actually pretty simple. When the grains are brought in, they are first soaked in water. Once soaked, they are taken out and drained. Then the grains are left to germinate which activates the process in which the starches that are in the grain become converted into sugars. This is important because the sugar is what the yeast feeds on to create the alcohol and carbonation of beer. (More on this subject in a later post.)

When the seeds of the grain begin to sprout, they are put into a kiln or oven and dried so that the enzymes do not continue to do their work and end up ruining the malt so that it can't be used. This process can define the flavors that and contributed by the malts. Base malts are kilned for the least amount of time and are usually the main ingredient to any beer recipe. The Crystal or Caramel malts come about my allowing the enzymes in the grains to break down carbohydrates to sugars before being put into the kiln. These malts tend to lend lighter flavors and color to beer like toast, biscuit, or nutty. These malts vary in a range of color and flavors that they impart on the beer. When these grains are roasted, they are put in the oven at a higher temperature that causes them to become a darker brown color and even sometimes black. These roasted malts give characteristics of burnt, chocolate, and coffee to beer. An example of a beer that uses these roasted malts is Guinness. Their brewing process, including how they uses their malts, is described HERE.

Malts in different states of roasting.

Upon being dried, or roasted fully, the grains are then crushed and put to soak in hot water. This creates the mash, where the enzymes are reactivate and become accelerated within a short period of time. This causes the last bit of starch in the mash to become broken down into sugar. Once this is done, the hops and are added to the boiling mixture. Once cooled down a bit, the yeast is added, thus making the mixture that will become one of the most infamous beverages around the world, beer!

So there is a little bit of information about malts. Hopefully you have gotten a better understand about an ingredient that is crucial to the making of beer.

What is your favorite Stout? What is it about that Stout that you prefer over other Stouts?

The Brewing Process, Simplified

You too can make beer! Brewing is the production of beer through steeping a starch (usually grains) in water and fermenting with yeast. The process of brewing is the process of steeping, such as with making tea. Brewing has taken place since the 6th millennium BCE in ancient Egypt. The basic ingredients of beer are water, a fermentable starch source (can be converted to alcohol) such as malted barley, a occasionally a secondary starch source (adjunct) such as corn or rice.

There are several steps in the brewing process, these are: malting, milling, mashing, lautering, boiling, fermenting, conditioning, filtering and finally packaging. But first, let us go over the basic ingredients of a beer. Water, beer is composed mostly of water. Different regions have water with different mineral components, better suited to making different types of beer. Dublin, Ireland has hard water suited to making a stout style (like Guinness). Pilsen, Czech Republic has soft water, well suited to making pale lager (like Pilsner Urquell).

The next ingredient needed is a starch, a fermentable ingredient that determines the strength and flavor of the beer. The most commonly used starch is malted grain. Grain is soaked in water and then dried in a kiln. Malting the grain produces enzymes that convert starches into fermentable sugars. Some brewers have produced gluten-free beer made with sorghum (a grain that does not contain gluten) with no barley malt for people that cannot digest gluten-containing grains.

Our next ingredient is hops, the flower of the hop vine. It is used as a flavoring and preservative agent. Hops lend several characteristics to beer, they contribute a bitterness that balances the sweetness of the malt. The bitterness of beers is measured on the International Bitterness Units (IBU's) scale. For more in-depth information about hops, read the blog post titled The Little Hop That Could. Our next important ingredient is yeast. Yeast metabolizes the sugars extracted from grains and produces alcohol and carbon dioxide. Some brewers add a clarifying agent to beer, this makes the beer appear bright and clean, rather than cloudy. Ok, now that you know the basic ingredients let's look at the brewing process!

All beers are brewed using a simple process. Refer to the Wachusett Brewing Company "Process" diagram above and use it as a guide. The malt is crushed to break apart the grain kernels and expose their carbohydrates and sugars, this process is called "milling". These cracked grains can better absorb water and their starchy insides are now exposed. Mashing is the next process, in which the starches are turned into sugars which can be fermented. Hot water is added, and naturally-occurring enzymes in the malt break down the starches into sugars. This conversion from starch to sugar is "saccharification" (a nice vocabulary word). The result of this mashing process is called "wort" (pronounced "wert"). The wort is strained through the mash tun in a process called lautering.

The wort is moved into a large tank and boiled with hops and occasionally with other herbs and/or sugars added. Boiling terminates the further breakdown of starches. At the end of the boil, the hopped wort settles in a vessel called a "whirlpool" in which solids are separated out. Boiling the wort ensures its sterility and prevents infections.  After the whirlpool, the wort is transferred rapidly to a heat exchanger to be cooled. Yeast is unable to grow in high temperatures, so an ideal temperature is very important. When the yeast is added to the wort, the frementation process begins and sugars become alcohol and carbon dioxide.

The beer then sits and conditions. Flavors become smoother, and unwanted flavors dissipate. Conditioning may take a week to several months, so the next time your favorite craft brewery runs out of a particular style, please be mindful of this potentially long conditioning process! Some beers are then filtered and are ready to be kegged or canned or bottled.

Read about the Samuel Adams brewing process on their website. If you are interested in a more in-depth resource on brewing, check out this book titled "The Brewer's Handbook". Or take a brewery tour, Wachusett Brewing Company offers tours Wednesday-Saturday. This is a great way to experience the scale of a production brewing operation. The next time you are making a homebrew, you are really just following many of these steps on a smaller scale!

Do you have better understanding of how the brewing process works? Have you ever done a brewery tour? We would love to hear from you!