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A Day at the Brewery: Anchor Steam Beer from Brewhouse to Bottle

Posted by at 8:22 pm | Category: Brewing Insights 2

Bob Brewer takes you through the brewing process for Anchor Steam Beer, from brewhouse to bottle.


Around 5:30 a.m. on any given day, the first-shift brewers arrive at Anchor, change into their signature white coveralls, and begin the first brew of the day. Today they are brewing Anchor Steam Beer – five separate brews to be exact – so the process repeats itself five times over.


The brewers must first mill the malt to be used in the brew. The malts which make up the greater portion of the mash are moved from the large storage silos up to a weighing mechanism housed in an enclosure on the roof above the brewhouse. This is essentially a scale in the form of a hopper that is designed to accept a certain weight of malt, then dump it into a chute that takes it down to the grist mill. From the mill, the milled malt, or “grist”, is then moved back up above the brewhouse to a holding vessel called the “grist case.”

Specialty malts used in smaller quantities in Anchor Steam (or any of our other beers) come to us in bags which are manually dumped into a small hopper above the mill, ground, and also moved to the grist case.


The makeup of the beer being brewed is determined by the quantity and roast of the malt by weight, otherwise known as the “malt bill”. The malt bill for Anchor Steam Beer includes two-row pale and caramel malts.

The next phase of the brewing process is called “mashing in.” This is where the grist is introduced into the mash tun and mixed with hot water. The hot water, along with enzymes created in the grain by malting, convert the starches in the grain to sugars.


During the “mashing” phase, the mash is kept swirling by a large propeller-like mechanism to insure proper mixing. The temperature of the mash can also be stepped up to insure maximum conversion.

Phase two in the brewhouse is “lautering,” which is essentially a straining and rinsing procedure. The hot water in the mash, which now contains the converted sugar from the malt, is separated in a second vessel called the lauter tun.

Lauter Tun

The whole mash is pumped over to the lauter tun which has a screened bottom and the liquid, now called “wort”, is drained off. A hydrometer is used to determine the sugar content of the wort, which in the case of almost all beers, is much higher than we want. The wort is diluted by sprinkling water over the top in a process called “sparging”. Sparging accomplishes two things, diluting the wort and rinsing the remaining sugars from the mash.


The sparged wort is pumped into the third brewhouse vessel, the kettle. The left behind mash or spent grain is dumped into a hopper under the brewhouse and then moved into a storage silo. The spent grain is sold to a dairy as cattle feed.


Back at the brewkettle, the wort is vigorously boiled for an hour or so and the hops are added. Boiling the wort accomplishes a few things. For one, it sterilizes it. It also converts most of the remaining starches and finally, it also provides an environment for the addition of the hops.


Hops contain various compounds that give the beer balance, bitterness, flavor and aroma. Adding the hops at different stages of the boil achieve differing things but basically it all has to do with flavor. We use all whole-cone hops rather than the processed hop pellets used by a majority of today’s craft breweries.


The brewers will weigh out the hops beforehand and bring them to the brewhouse to be added to the wort.The first addition of hops is done as soon as the wort begins to boil.


These hops will boil the longest and add bitterness. The second addition happens about halfway through the boil and provides some bittering and some flavor. The last addition happens at the end of the boil and since the hops are not subjected to a long exposure to heat, they retain many volatile esters that give the finished beer its aroma.


Up to this point in we have taken the malt of various roasts and milled it and blended it with hot water for a time to convert the starch to sugar. The liquid, now called wort, containing the sugar, is strained from the mash, diluted, and pumped into the brew kettle to boil. Hops are added to the boiling wort in several stages. All in all a somewhat complicated procedure just to get starch to convert to sugar. But we’re far from done yet.

After leaving the brewhouse, the wort goes to fermentation. The draining of the brew kettle is called the “strike” and runs the wort through a device that removes the spent hops from the liquid. In a somewhat continuous process the wort is then pumped up into a large tank – strangely enough called a “hot wort tank” – in a whirlpooling manner that removes some of the proteins can make finished beer hazy when chilled. Upon exiting the tank the wort is transferred into a fermenter, running through a heat exchanger along the way to cool it down.


Fermentation is where the real magic of brewing beer happens. It’s essentially a metabolic function of yeast consuming sugar and converting it into carbon dioxide and ethyl alcohol. When the wort is transferred into the fermenter we “pitch” in a quantity of yeast to initiate the process.


As the yeast consumes the sugar it also begins to multiply exponentially which accelerates the rate of fermentation. Heat is also generated by fermentation and must be controlled to a degree depending on whether we are making ale or lager. We use a shallow, open fermenter system for Anchor Steam Beer, which is a lager.

Open fermentation is a rarity these days. It was originally utilized as a method of radiant cooling of the fermentation by means of shallow depth and wide surface area of the wort being exposed to atmosphere in an age preceding mechanical refrigeration. Quite unnecessary in modern times as well as being challenging and labor intensive, we still employ it for the purposes of preserving our heritage and traditions. The temperature of the fermenter rises higher than that which is ideal for lagers but that is part of the uniqueness of Anchor Steam.


The process of fermentation for Anchor Steam takes 36 hours in the open fermenter after which the beer is transferred to the cellar tanks for finishing. Our brew house and fermenters are located a few floors above the cellar, so this transfer, which we call ”dropping,” is achieved by gravity – with the help of pumps along the way.


Most of our cellar tanks hold around three brews, although a few of the older ones are smaller. We will fill the tank to 85% capacity and then top off the remaining 15% with half-fermented wort. This process is called “krausening” and promotes a mild second fermentation that finishes and carbonates the beer. The cellaring process takes about two weeks but can last longer.

While the beer is being brewed, fermented, and cellared, the packaging crew is working to bottle and keg beer that has been finished. The cellar crew pumps finished beer through a filtration and pasteurization process and collects the finished product in special tanks that feed the packaging lines. These are called either “bottling tanks” or “bright tanks”. They feed both the bottle and keg lines. Since the packaging moves faster than the filter does, the cellar crew has to get a head start. Usually they will have a bottling tank full and ready to go.

For bottling, the beer is pumped up to the filing line where there’s a lot of action with several things happening at once. Empty bottles are fed into one end of the line and run through a rinser, then on to the filler. The filler, which looks like a huge rotating drum and has 60 filling heads, grabs the bottles and fills them as it rotates one revolution. The filled bottles are immediately capped sent down the conveyor to a labeler, passing through a tunnel that dries them along the way.


In a continuous process, the freshly filled and labeled bottles are run through a case packer, get palletized, and put into storage to await shipment.


Keg filling, or “racking,” is much the same only slower and with a larger container. Since the kegs are constantly re-used, they are first run through an external washer to scrub the outside. Sort of like a giant dishwasher. The scrubbed kegs are then run through a three-step automated machine that cleanses, rinses and sanitizes, and then fills them. The full kegs are run over a scale which weighs them to ensure a complete fill and then palletized for shipment. Bottling and racking rooms are adjacent to each other and the process happen concurrently.


While all this is going on, there are trucks coming and going all day long picking up beer or spent grains and delivering raw materials and packaging.


It’s a busy place. The tempo dies down around 4 p.m. as the packaging lines shut down and the truck traffic stops. A few folks are cleaning up in the cellar and around the bottle and keg lines, but the brewers still have some time to go. The last of them won’t be done until 10 p.m. or later. The following morning we start all over again. Brewers are at work seven days a week, as are a couple of folks doing the drops. Packaging and filtration operate Monday through Friday.

So, how much beer do we make in a typical day? How many bottles or kegs is that? A lot of people ask so I’ll break it down.

We measure our output in barrels. A barrel is an inexact unit of measurement, in that there are differing volumes depending on what you are measuring – a barrel of oil or a barrel of beer or whatever. All are different. The brewing industry in America measures a barrel of beer, or one beer barrel (BBL), at 31 US gallons. Countries using the Metric system measure in hectoliters which are 26.4 US gallons.

Our brew batch size is 125 beer barrels. Sometimes the yield is less depending on the beer we’re making but I’ll use that number.

  • 125 BBL x 31 gallons = 3,875 gallons per brew.
  • Anchor kegs are metric at 50 liters/13.2 gallons. 3,875 gallons = 293.56 kegs per brew.
  • Anchor cases are 24 12-ounce bottles, 2.25 gallons. 3,875 gallons = 1,550 cases per brew.

We usually brew five brews a day, sometimes six. Less on weekends. Using five brews daily as an average that comes out to 625 barrels per day or:

  • 19,375 gallons per day or
  • 1467.8 kegs per day or
  • 8,611 cases per day or
  • A grand total of 206,666 bottles per day

There is always a mix of packages and a certain amount of liquid is lost during the various transfers and processes, so the true final yield is always somewhat less, but all in all, not a bad day’s work.

Next time you Raise Your Anchor with a bottle or pint of Anchor Steam Beer, you’ll know a little bit more about the work that goes into each and every brew.


Readers Comments (2)

Great overview. Do you use local SF water from the tap?

by Biggsie | Nov 24 | Reply

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