At Boston Breweries, we brew 5 days a week, 24 hours a day. We follow a traditional brewing process to craft our beers.

Malt

The day starts by preparing specially selected malted barley, according to my recipe.  All our barley is imported from Belgium and we have 25 different malts we can choose from. For example we use two-row Pilsner malt in our lagers. 

Our Whale Tale Ale is crafted using Pale Ale malt, which adds a strong malty flavour, as well as Crystal malt, which imparts a rich, caramel-sweet aroma, a unique toffee-like flavour, as well as its golden colour. 

My Johnny Gold Weiss recipe also uses malted wheat, which enhances the typical Bavarian wheat beer flavour.  Wheat malt is essential in making wheat beers thanks to its protein that gives the beer a fuller mouth feel and enhanced beer head stability.

Crushing

Once we have weighed out our quantities of malt, we send it to our double-roller grain crusher.  Our aim is to simply crack the husks to allow water to extract sugars during the mash.  We don't want to crush it too finely so as to make flour.  The RPM of the crushing rollers is critical in achieving this.

Mashing

The crushed grain is now poured into the mash tun along with heated water.  We follow a step mash process.  The water and barley mixture is heated to a specific temperature for a specific amount of time.  Accuracy is paramount; there is no room for error.  The steps (time and temperature) are determined by which enzymes from the barley we want to activate.  These enzymes break down the sugars in the grain.  If we are brewing ale, which has a large amount of unfermentable sugars, we would follow a very different set of steps to that of a lager.

A mash consists of five steps which take about 2.5 hours to complete.  The temperature is controlled by steam moving through a specially designed steam-jacket on the mash tun. On completion of the mash, the liquid is pumped into the lauter tun.

Lautering

The lauter tun has a wedge wire screen on the bottom.  This has small slots in it to separate the bigger husks from the liquid. The mixture is allowed to settle, so that the larger particles fall to the bottom and the finer particles settle on top.  This creates a filter bed out of the grain husks.  This is the reason we do not want to crush the barley too fine, as that would create flour, which would block the filter bed.

The wort (pronounced: wert), as the liquid is now known, is pumped from the bottom of the lauter tun back on top of the grain bed.  It is continually recirculated until the particles are filtered out and it becomes clear.

The Boil

We now pump this wort into the boiler while we also spray hot water over the grain bed in the lauter tun to further remove the sugars from the grain. We use a refractometer to check that all the sugars have been removed. The wort is boiled for 90 minutes so as to ensure our wort is sterile when it reaches the fermenters.  It also causes existing proteins to clump together and then drop to the bottom of the tank in what is known as a hot break.

During the boil we also add hops at different times.  We use compressed hop flowers in the form of pellets.  This makes transport and storage easier and more efficient. Hops are added for different purposes such as bittering, flavour, as well as aroma.  Bittering hops, such as Southern Promise, boil for the full 90 minutes.  Flavour hops, like Cascade or Northern Brewer, boil for 45minutes, whereas aroma hops, such as Saaz, boil for only 5 minutes.

Cooling

On completion of the boil, the wort is whirlpooled and then left to rest for 30 minutes.  This gives time for the proteins that have clumped together with each other and the hops to fall to the bottom.

The brilliantly clear wort is then pumped into the fermenter via a heat exchanger to bring it down to fermentation temperature.  This temperature varies according to the type of beer being brewed.  - 10-14°C for lagers, somewhat warmer for ales, and even as high as 24°C for weiss beers.

Yeast

Yeast is now added to the fermenter.  We use different types of yeast for lagers, ales, strong ales and weiss beer.  Some are top, and others are bottom fermenting yeasts.  Oxygen is added to the wort to encourage yeast reproduction through cell division.  The yeast then consumes all the fermentable sugars and produces alcohol and CO².

This process takes about 7 days for lagers, and 4 for ale.  The fermenter is then chilled to 1°C.  Chilling helps the yeast drop down into the cone of the fermenter so that we can remove it and use it for the next batch that is coming out of the mash tun.  We leave the beer for another 7 days at this temperature.

Our stronger beers are dry hopped at this stage. To dry hop, we add hops directly to the fermenter and let it sit for 3 weeks. This gives a very unique flavour to the beer.

Filtering

The beer is now pumped through a diatomaceous earth filter.  The filter removes all the yeast and anything else that is larger than one micron e.g. larger proteins.  The beer is now perfectly clear. We do not sterile filter down to 0.4 micron as we have found that this technique tends to remove more flavour and colour than we would want.  The beer sits again at 1°C for a week in the bright beer tank.

Interestingly, Johnny Gold Weiss is bottle conditioned, - so we do not filter it.  Instead, an amount of wort (which still holds the sugars) is added to the fermented beer and it goes straight to bottling.  The small amount of yeast left in the beer will then ferment this wort and carbonate the beer.

Kegging

We use a machine especially made for kegging. The keg is attached to the machine via a cleaning coupler.  It is rinsed with cold water; triple cleaned, rinsed with hot water, and then steam sterilized.  CO² is then pumped into the keg so as to flush out all the oxygen. After fermentation the beer must never come into contact with oxygen. If it does, the shelf life will be severely shortened as the beer will oxidize. The keg is then hooked up to the filler and is filled under pressure.  It is then stored in one of our cold rooms at 1°C.

Bottling

The bottles are rinsed with ozonated, sterile water and added to the filling line.  Thereafter, the labels are applied.  The bottles then have all the oxygen removed through a double evacuation system.  The bottle is then pressurized with CO² and filled.  The beer flows into the bottle under pressure and then the cap is applied.  The foam from the beer ensures that there is no oxygen pickup. Our bottling area is also ozonated to keep the surrounding air sterile. The bottles are then shrink-wrapped into 6 or 4 packs and then packed into boxes.  These are then stored in one of our cold rooms at 1°C to ensure that our beer it is at its absolute freshest when it reaches you.