The Physics Factbook™
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|Beer: Mixing the Mash. Encyclopedia Britannica. 2008.||"Traditionally, mashing may be one of two distinct types. The simplest process, infusion mashing, uses a well-modified malt, two to three volumes of water per volume of grist, a single vessel (called a mash tun), and a single temperature in the range of 62 to 67 °C (144 to 153 °F)."||62–67 °C|
|Troncoso, Alex. Article - Strike Temperature. Grain and Grape.||"As all mash brewers know, the temperature of the mash greatly affects the finished beer. Most books will list the optimum mash temperature range of 64 to 68 oC [sic] with a mash conducted at 68oC resulting in a dextrinous beer (ie. high final gravity) and a mash conducted at 64oC resulting in a well attenuated beer (ie. low final gravity)."||64–68 °C|
|Physics Geek: Wheat Beer Mashing. 20 June 2006.||"2) Heat the mash up to between 150-155 degrees and hold there for 60-70 minutes. This is the sacharification rest, where the long branch-chain sugars get converted into smaller, fermentable sugars."||65.6–68.3 °C|
|Palmer, John. Chapter 16 - the Methods of Mashing. How to Brew. 1999.||"All of the crushed malt is mixed (infused) with hot water to achieve a mash temperature of 150-158F, depending on the style of beer being made."||65.6–70.0 °C|
|Beer and Spirits Processing, Production. IDL Consulting.||"Beerzym AMYL: is a special liquid enzyme. It is used for the liquefaction of starch in beer production with malt and adjuncts using infusion mash temperatures up to 75 degrees C. / 167 degrees F."||75 °C|
There are many different ways to brew beer. The reason being is that there are many different types and styles of beer. The steps to brewing a beer are as follows: grain processing, germination, kilning, milling, mashing, pitching, and fermentation. Although all of these steps are needed to make a beer, for our purposes we will be focusing on only the mashing process because during this step is when the brewing process actually begins. Mashing is when sugars are created from complex carbohydrates or starches in the grain by simply applying heat. Chemical bonds break and the resulting pieces are smaller, simpler carbohydrate sugars that can be fermented by yeast.
The question is how much heat is needed to make this work. No matter what type of beer being brewed, the water that will be used as the brew water must first be boiled (100 °C). The stove must be turned off and the water must cool down before the yeast and other ingredients are added. If the water is still too hot the yeast will die. From five different sources I have used, I have concluded that the temperature at which beer is brewed can be within a range any where from 62 to 75 °C. The temperature in which beer is brewed is important because the temperature determines the type of beer that the brew will turn out to be. When the temperature is higher the yield is greater and the fermentability is lower. It's vice versa if the temperature is lower.
Evan Borochina -- 2008
|Brewing. Wikipedia, 5 Jun 2005.||"Finally, a mash rest temperature of 149 to 160 °F (65 to 71 °C) is used to convert the starches in the malt to sugar, which is then usable by the yeast later in the brewing process."||65-71 °C|
|Rhodes, Christine P. The Encyclopedia of Beer. New York: Henry Holt, 1995.||
|Mosher, Randy. A Turn-of-the-Century British Account of Selected Belgian Brewing Methods. November/December 1994.||"The flakes may be added directly to one-third of the malt mash that was transferred to the chain chopper and the mixture quickly raised to 158 °F (70 °C)."||70 °C|
|Ensminger, Peter A. The History and Brewing Methods of Pilsner Urquell: Divining the Source of the World's Most Imitated Beer. May/August 1997.||
|Rhodes, Christine P. The Encyclopedia of Beer. New York: Henry Holt, 1995.||"Normally, a protein rest at 125 °F to 130 °F (65 °C to 71 °C) in achieved first, followed by a saccharification rest at 149 °F (65 °C) and then maybe a progressive rise to 165 °F (74 °C)."||65–74 °C|
Beer is a common type of beverage today and has been for hundreds of years. Today there are various types of beer that is brewed with thousands of breweries in the world.
Brewing is the method used to produce beer through fermentation (metabolic breakdown of a nutrient molecule). It is a careful and tedious process. First barley grain is prepared to germinate (malting), during which the natural enzymes of the grain convert the seed starch to maltose, and then to glucose. Then additional hot water is added to the draining grain to rinse more sugar out of the grain (steeping or sparging). The resulting liquid or wort is the substance to which yeast is added to convert sugar to alcohol. Hops, which are certain flowers, are added during the process to give a distinguishing flavor.
In the end, it is the temperature that the beer is brewed at that determines its taste and quality.
To reach the final desired temperature, brewers have to go through a step called Mashing. Mashing is the process of mixing water with grains at specific temperatures for specific periods of time to promote enzyme activity that converts starches to fermentable sugars and breaks down complex proteins.
There are several kinds of mashing methods that will result in different temperatures. The single-step infusions mash involves one temperature step. The water and barley are mashed in at 64 °to 70 °C (148 °to 158 °F). In an infusion mash,the grains until the mixture reaches the desired temperature of about 65.5 °C or 150 °F. Step mash is basically ab infusion step with the difference of beginning at a lower temperature and being raised to 64 °to 70 °C (148 °F to 158 °F). Decoction Mash is the most complex method of mashing. It involves the break down of proteins and starches in the boiling phase. The actual step of removing part of the mash and boiling is called decoction. The mash begins with cold water stirred into grains; hot water is added to bring the temperature 53 °C (127 °F) to break down the lager proteins; the second addition raises the mash temperature to 143 °F (62 °C) for starch conversion; and the third brings the temperature to about 73 °C (163 °F) for mash-out.
Mashing out is actually the last step of the process. In general there is a five minute rest which will cause the beer to reach its final temperature in the brewing process at 70 °C (158 °F).
The final temperature of the brewed beer is not exact. Depending on the method of brewing and the type of beer brewed, the result can be a range of temperatures. However, no matter the method, the final temperature will still be close to about 70 °C.
Orin Zahra -- 2005
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