The Legend Shares Brew House Knowledge

The Legend Shares Brew House Knowledge

Horst Dornbusch

Leading Author, Speaker
& International Beer Consultant

Horst Dornbusch is internationally known in the brewing industry as a consultant, brew equipment designer, beer recipe creator, brewer, beer judge, event speaker, and multilingual author. He was born in Germany and educated in both Germany and the United States. He is now a German-American dual citizen and lives in Massachusetts, USA. Over the past quarter of a century, he has published hundreds of articles, as well as many books, about the technical, sensory, and economic aspects of beer and beer-making. His books include PROST! The Story of German Beer (1997), Altbier (1998), Bavarian Helles (2000), The Ultimate Almanac of World Beer Recipes (2010), Die Großen Biersorten der BRAUWELT® (2014), Beer Styles from around the World (2015), and Das Große BRAUWELT® Lexikon der Biersorten (forthcoming in the fall of 2017). In addition, he was the Associate Editor of and a major contributor to the acclaimed 900-page reference work, The Oxford Companion to Beer (2011). Currently, he is working with Thomas-Kraus Weyermann on a book about dark lager brewing. In India, his association with Pradeep Verma – Adviser to Brewer World – goes over a decade.

Have you been saving your rupees, and are you ready to take the plunge? A fully stocked brewery, with all its shiny attachments. Are you fully aware that it may take much more than a year to purchase all the equipment, to execute the build-out, and to install your shiny new stainless steel gadgets? You know that at the end of your beginning, that is, when you begin to make beer, you will not have too many rupees left. Let’s all hope you spend your money wisely, and that you did not listen to the wrong sales person—the one who put his or her profits ahead of your interests. In short, let’s hope the equipment you bought will let you make the beer you have planned to make!

Perhaps the single most important piece of equipment you will purchase when starting a brewery (or when expanding an existing one) is the brew house. Depending on the complexity of your infrastructure and on whether or not you need a fancy, high-speed bottling line, the brew house may absorb as much as one-half of your entire up-front investment in a brewery. Thus, you must choose carefully and deliberately! And the best way to know what you need is knowing exactly which beers you wish to make.

Broadly speaking, there are only two prototypical brewing cultures in the world, the British and the German. All other brewing cultures have evolved as derivatives or off-shoots of these two. More Importantly, the beers that have come out of these two cultures require very different brew houses! Thus, before you consider anything else, you must decide if you will be making mostly British-style ales or German-style lagers, or both. If you are planning to start an ale brewery, your equipment can be off-the-shelf, relatively simple, and less expensive. On the other hand, if you are planning a lager brewery, chances are that your off-the-shelf equipment will be more complex and thus more expensive. If you are planning to make a combination beer portfolio of both ales and lagers, your best bet is to obtain the services of a brew systems expert who can design a custom brew house configured for your specific needs. The following is an elaboration of the key features of the two ideally typical sets of brew house equipment for ale and lager-making.

Ale Brew House Features

The most elementary classic brew house configuration for ales is a two-vessel system consisting of a mash-lauter trub fitted with a V-wire or laser-cut false bottom and a mash rake, as well as a brew kettle for boiling the extract run-off, that is, the wort. In the first vessel, you infuse milled malt with hot brewing liquor to form a mash. Usually the water temperature is kept at a compromise level of roughly 67°C (152°F), which is between the peak temperatures for alpha and beta amylase, when both enzymes are active simultaneously. Alpha amylase activity (i.e. the conversion of starches into complex sugars) starts at about 60°C (140°F), and it peaks at about 72°C (162°F). These enzymes are denatured at about 80°C (176°F). Beta amylase activity (i.e. the conversion of starches and complex, unfermentable sugars into simple, fermentable sugars) starts at about 40°C (104°F), and it peaks at about 65°C (149°F). These enzymes are denatured at about 70°C (158°F).

Once the mash-in is complete, you allow the grain enzymes the requisite time to work their magic of converting grain starches into fermentable sugars (mostly maltose), and then you drain the now sugary liquid into the second vessel for a boil and the addition of hops. As you drain the extract, you add fresh hot brewing liquor via sparging. The temperature of the sparge water can be higher than that of the mash water. This allows the mash to reach the mash-out temperature for improved extraction. This temperature is rarely below the beta amylase denature temperature of 70°C (158°F) and rarely above 80°C (176°F), which is the alpha amylase denature temperature, as well as the liquefaction temperature of any residual starches left in the mash. The boil has several precise functions: It sterilizes the wort, it evaporates unpleasant volatiles (mostly DMS), it coagulates unwanted large-molecular proteins, and it isomerizes the hop’s alpha acids into wort-soluble iso-alpha-acids.

More importantly, in this system, your mash will be relatively thick, with a  water-to-grist ratio of as low as 1:1. Once the mash-in is complete, you leave this high-viscosity mash undisturbed until grain-out. In this system, each vessel carries out two functions: Mashing and lautering in the first vessel, and boiling and whirlpooling in the second vessel. If you want to be fancy, you can install recirculation plumbing with a tangential inlet and a strong pump to create a whirlpool inside the kettle for better trub sedimentation. If you wish to chase several batches through such a system in rapid succession, you can add a buffer tank between the mash-lauter tun and the kettle, as well as a separate whirlpool. This configuration allows you to lauter the second batch, while the first batch is still boiling; and it allows you to transfer the second batch into the kettle while the first batch is still whirlpooling. Finally, you can pump the finished wort through a heat exchanger into the fermenter into which you have pitched yeast.

Lager Brew House Features

It is rare that a lager brew house has only two multi-function vessels. Instead, at the very minimum, it has a separate mash tun or mash mixer and a lauter tun. This is because lager mashes are traditionally very thin, with a low-viscosity water-to-grist ratio of as high as 4:1. In fact, up to 80% of the net kettle volume may be used as mash liquor in the mash tun. This type of grain-water mix calls for a relatively tall vessel fitted with a fast rotating mash agitator. Also, lager mashes often require a multi-step infusion, or multi-temperature decoction mash, with heat applied to the vessel via steam-heated jackets. Applying such heat to a stationary high-viscosity ale mash would merely scorch the peripheral layers of the grist without sufficient heat transfer to the centre of the mash. In an agitated low-viscosity lager mash, on the other hand, there is no scorching. Instead, there is a relatively even heat transfer throughout the entire mash.

Perhaps the single most important piece of equipment you will purchase when starting a brewery (or when expanding an existing one) is the brew house. Depending on the complexity of your infrastructure and on whether or not you need a fancy, high-speed bottling line, the brew house may absorb as much as one-half of your entire up-front investment in a brewery. Thus, you must choose carefully and deliberately! And the best way to know what you need is knowing exactly which beers you wish to make.

At the end of the mashing period, this thin mash is slurry-pumped into the lauter tun, where it is allowed to remain stationary and settle. While the mash tun is tall, the lauter tun aspect ratio (height-to-width) calls for a wider design so that the grain load above the false bottom is in the vicinity of 200 kg per m2. This generally translates into a grain bed depth of roughly 35 cm (approx. 14”) for average original gravities. Lager mash tuns often do not have sparging fittings. Instead, the huge volume of water is drawn off almost completely and the lauter tun is filled with a so-called Nachguss (literally an “after-pour” in German) for a second run-off. The kettle in a lager brew house is identical to that of an ale brew house. Again, just as in an ale brew house, a buffer tank between the lauter tun and the kettle, as well as a separate whirlpool allow for a speedily chasing of sequential batches.

 A small 4.5 hl, 4-vessel, combination brew system designed by the author. It features (from left to right) mash-mixer, mash-lauter tun, brew kettle, and whirlpool.

A small 4.5 hl, 4-vessel, combination brew system designed by the author. It features (from left to right) mash-mixer, mash-lauter tun, brew kettle, and whirlpool.


Combination Brew House Features

Brew houses designed for both lager and ale-making are usually custom produced. They tend to have both a lager mash tun and an ale mash-lauter tun. If the brewery uses a pre-mash grist hydrator, both vessels are fitted with one. The grain-supply system (such as an auger) can be moved from one to the other vessel for the mash-in. Only low-viscosity mashes start in the lauter tun, while high-viscosity singe-temperature mashes start in the mash-lauter tun.

To sum up, it is difficult to mix thick mashes for ale-making in an off-the-shelf classic lager brew house, because thick mashes cannot be slurry-pumped from one vessel to the next. Conversely, it is almost impossible to mix classic, low-viscosity lager mashes in a standard off-the-shelf ale brew house, because the mash-lauter tun is too small to hold that much thin mash.

© Horst Dornbusch 2017.

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