A homebrewer walks into a brewery – part 2

Max from the tiny brewery Brasserie Lance-Pierre in Switzerland is doing an internship at renowned Brew By Numbers (BBNo) in London. Over a few instalments, he writes about how it is for a “homebrewer” to be working in a professional and world-class brewery. This is part 2.

>> Read part 1 here.

Every week has a different schedule: Brew day, transfer day, package day and a lot of other task to do, like dry-hopping, adding coffee beans to a tank, do measures of density and pH or pressurizing tanks. It’s a lot of work, shared between the five members of the brew team, including me. We brew around 3 times a week, and those are my favorite days because this is where we manipulate the matter. Here’s what the brewer’s job looks like on a day like this.


Brew By Numbers are well known for their endless list of beers, well numbered by style and recipe. I was relieved to not have to remember them all. If you, however, want to try to memorise them, you can go here.
Dave and Tom (owners of BBNo) and the brew team conceive recipes collectively. Tasting sessions are organise by Toby, one of the brewers, with all the staff discussing the last beers produced.

Today the recipe is a Saison at 5.8%, brewed exclusively for The Wigmore by Michel Roux Jr..

Here is the recipe for 20 litres.

Recipe Specifics
Batch Size (Liter): 20
Total Grain (Kg): 3.36
Anticipated OG: 1.0413
Brewhouse Efficiency: 85 %
Wort Boil Time: 75 Minutes

63% Low Color Marris Otter – 2100g
12% Wheat malt – 422g
6% Flaked wheat – 210g
6% Oats – 210g
6% Rye – 210g
6% Invert Sugar – 210g

Warrior – 17g (60 minutes)
Yeast Vit – 2g (0minute)
Mosaic – 84g (0 minute, 85°C)
Grapefruit zest – 25g (0 minute, 85°C)

BBNo Saison – French saison strain

Water Profile
Profile: Brussel

11916173172322 (HCO3)8

Mash Schedule
Sacch Rest – 90 min @ 64°C

Hot Liquor Tank

Before brewing, the first thing to do is to analyse the water that we will use. We can see the water report of the city on the internet, but if there is some rain or something in the pipe, the report is useless. The best way to be sure of the composition of the water is to do it ourselves. With some measuring tools and a bit of patience, we check the pH, chlorine, sulphate and calcium contained in the HLT (Hot Liquor Tank).

Depending on the beer styles, there are four profiles of water to choose from. To adapt the water, gypsum and lactic acid are added to the mash. The corrected water will help the malt’s enzymes to decompose the different sugars.

For this Saison, the water profile is based on Brussel’s one, following the calculator of brewersfriend.com.

Mash Tun

The first thing to do in the morning is to warm up the Mash Tune. In London it’s very common to see vessels without heat elements. Therefore, you’re using hot water to increase the temperature before filling it up with the calculated volume of water.

The malt arrives already crushed from the producer. The bags are sorted by type: Normal and specialities malts to mix them harmoniously. An auger carries the malt straight to the mash tune. One brewer is downstairs and loads up all the bags, while another, armed with a paddle, mixes the grain vigorously.

We only do single step mash, but the duration might change between the beers and the result we want. There is always a period before recirculation through the under back/grant, but the total duration is usually between 60 and 90 minutes.

The sparge is the tricky part: The flow of water must be regulated to be sure to not drown the wort, while not being too slow, so we don’t loose too much time. Depending on the recipe, the mash can easily be clogged by a thick cake and that makes us loose time.


All the wort is now in the Kettle, the highest vessel in the brewery; a real watchtower. The temperature is close to 100°C and our eyes are on the small hole from where some wort will overflow when it boils. That is our signal to start the 15 minutes timer for the “preboil”. GO!

Time to add the bitter hop. In this recipe we use Taurus, also known as Hallertauer Taurus. In other beers we also use Warrior hop as a bittering one. Sometimes when I’m too industrious to empty a bag until the last pellet, my colleagues tell me “Come on, it won’t make any difference on 10 kilos of hops!” I always answer with a smile “Yes, it could feed a home brewer”.

During the boil, Irish moss finings, vegan friendly, is also added, depending on the recipe. This is tablets, looking a bit like the vitamins that you put in water.


The height of the kettle starts to make sense now. It’s based on a traditional Germanic style system. Connected to the whirlpool by a large pipe, the boiling wort is dropped from the kettle to create a vortex in the lower vessel; a whirlpool is created! Some yeast vitamins and a hint of zinc are added at the beginning.

A brewer is on top of the kettle, looking for the last drop. Perched on a small ladder with a bucket full of hop in my arms, I wait for the signal. Gosh! The hop smells so good, We should use them for shampoos, or even perfume… Here comes the signal! I drop the late hops in the vortex and I close the main opening. We wait few minutes, wort’s temperature is now 85°C, time to add the aromatic hops.


Everything is set up: The heat exchanger and the pump, in line with the flow meter and the thermometer, are connected to the James Brown Tank, the one reserved for the beers using the season yeast.

Of the ten tanks in the brewery, two are used only for Saison and another one, Rick James, is reserved for the Brett yeast. The Rick James Tank is a bit of the wild animal of the brewery. We are all a bit scared of what effect the Super Freak could have on the other tanks. To prevent any bad effects, there is special material only used for the Freak: separate pump, hoes and pipes. The Brett yeast are also stoked in a special fermenter, Funk City, controlled every Friday.

The BBNo season yeast is collected to be reused; we get it ready the day before brewing. Stocked in a 30 litres keg, we measure with a scale the volume of yeast we want to add for the fermentation.

Now back to the brewday: Slowly but surely, the wort is cooled and routed to James Brown. The cooling water, now around 70°C is routed back to the HLT.

We are close to our target volume, so we check what we still have inside the whirlpool. A small island of hops and malt particles is standing in the middle of the wort. Through the seeglass, we see that the mighty post-boil wort is starting to be spotted with hops.

We close the valves.

The brewing is over.

In few days the yeast will be collected from the bottom, just before we transfer it in another fermenter to clean a bit the beer.


Every brewer will agree with me that cleaning stuff is a huge part of the job. A cleaning protocol is followed to ensure that everybody in the brewery cleans the same way without forgetting a step:

  • Hot water to clean the big mess
  • Hot caustic circulation (4% – 20 minutes)
  • Rinse with hot water
  • Rinse with cold water
  • Cold peracetic acid (1% – 5 minutes)


Let’s face it, we don’t really brew beer, we brew syrup and the yeasts does the beer. But we have to control our work and theirs. Every day we collect samples from every fermenter to measure density and pH. When the fermentation seems completed, a diacetyl test is made.
To do a diacetyl test, you need:

  • 2 small glasses
  • aluminium foil
  • 2 pitchers
  1. in every glass put around 20ml of beer.
  2. use aluminium foil to cap each glass.
  3. one of the glasses will be a tell-tale, so leave it like this.
  4. put the other one in a pitcher, add water to the pitcher to wrap the glass and warm it up. The temperature must be between 55°C and 60°C
  5. leave the glass in the pitcher for 15 minutes.
  6. After 15 minutes, put the glass in a second pitcher filled with cold water to decrease the temperature of the sample until 20°C.
  7. Now lift the aluminium cap and smell the sample. If there is a buttery smell, you still have diacetyl in your beer. If you have some doubt, smell the tell-tale glass to compare.

We compare our results as often as possible with the other brewers, ask them to do a measure by themselves without telling them our previous result to not influence them.

Still a lot of work

It’s my 8th week at Brew By Numbers. I’m more independent every day, running the tests by myself, preparing the ingredients and the material without asking what to do, knowing what I am doing.
I learn everyday about brewing, fermenting and even more: I get to explore the beer community, with the good reputation of the brewery opening doors for me to meet and talk to other professionals.

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