Home brewing is a great hobby. I have been brewing at home for a while now and every time I enjoy it that little bit more. One aspect of home brewing that really appeals to me is the learning curve one needs to go through to produce a good beer. However, what I found is, that whoever you ask for advice, or whichever book / website you look at, you will get a different answer. Once I heard a saying that if you ask three brewers for advice, you will get five different answers. That made me think, how does the brewing process look at commercial breweries? Are we, home brewers, really following the same processes as the commercial breweries?
A few days later I was on my way to Kelburn Brewery, a local family brewery based in Kelburn, south of Glasgow. The super-kind people there were willing to let me spend a day alongside their brewers, watching every part of the process and helping with the less risky parts.
The morning was a little bit hectic for me as it was in the middle of the Commonwealth Games. I had to drive through the Glasgow city centre, and with the road traffic completely rearranged I got… lost. So a hundred swears and few shouts later I arrived approximately an hour late, still welcomed by the Kelburn crew.
The place sits in the middle of the local industrial units. From the outside you would not tell there is a brewery there, if it wasn’t for the stacks of casks sitting on the driveway.
The people who welcomed me were the Kelburn’s brewery head brewer Andrew Molloy, brewer Mark Allan, and the drayman Shaw Monaghan. Unfortunately due to my delay I missed the early stages of mashing, as the grains were already in, and about 30min into the mashing process. The smell was already amazing. And I couldn’t help but smile. Andrew used this time to give me a quick tour around the brewery and describe the process they normally go through.
Kelburn’s Brewery mask tun – this is where part of the magic happens.
The brewery is a 10BBL (approx. 1600 litres) set up to produce real ales. This basically means they do not use physical filtering and do not carbonate their beers beyond what the natural fermentation provides. Following the fermentation the beer goes into conditioning tanks for a few weeks, and then straight into the casks, where it undergoes a secondary conditioning. You can refer to the CAMRA website for more information on real ales. I am sure that I will also write a piece on real ales in the near future.
Today Andrew and Mark were brewing an award winning session pale ale Goldihops.
The grain bill comprises primarily Maris Otter with some crystal and wheat. The whole Kelburn crew were incredibly open about everything they do, sharing every bit of knowledge with me. The recipe book sat on the table in the next room and Andrew was more than happy to show it to me and answer any questions I asked.
Sightseeing however did not last long and I got some work to do. In a true brewery style – I was shown where the cask washer is. The task involved emptying the casks that arrived from the pubs, cleaning them and preparing for the next fill. If you have never lifted a cask before then believe me, after 20-30 casks you do feel your back. In meantime the mashing was over and Mark looked after sparging.
Mashing completed.
The water used for sparging comes straight from the hot liquor tank. Water is heated up since the evening before, to reach mid 70 degrees in the morning, ready for mashing (target mash temperature was 65deg). Then the water is kept hot for sparging. Mark was kept busy at the underback monitoring the flow and gravity. As far as I remember, he was considering sparging to be completed when the wort at the underback reached 1.006, which took over an hour to complete.
Underback with all the sugary goodness flowing through it.
Mark looking for the magic number.
All this time Andrew was supervising the whole process, if not constantly checking if the equipment is ready for the next stages, then ensuring everything is clean and tidy. A large part of his time was also occupied by answering to my endless questions.
Looking inside the kettle, I noticed that the wort flows into the kettle at the top of the tank, and then drops freely some distance to reach the bottom of the tank. This got me thinking about the Hot-Side Aeration.
Hot-Side Aeration (HAS) was a topic that interested me at that time particularly. HSA, as the theory states, introduces oxygen into the wort which could cause some compounds to oxidize, leading to certain off-flavours. The problem is that everyone knows the theory, but it is very difficult to find any proof that it really affects your beer on a home brew scale. I thought I would put Andrew on the spot, and ask. As it turns out, despite the full awareness of potential hot-side aeration, Andrew was not concerned with it. In all the years of brewing he has got behind his belt, and on this particular equipment, they never experienced any off-flavours that could be related to HSA. Case closed.
Saying that, it is worth looking at the HSA experiment undertaken by boys at Basic Brewing (link), with interesting conclusions.
I don’t think Andrew liked my interrogation, as he handed me a shovel straight after, and pointed towards the mash tun. Well, someone had to do it, and I am telling you that standing in a waist-deep insulated tin full of hot spent grain, and still trying to do some work is not the most relaxing of exercises. This was followed by a good scrub and a wash with a caustic solution, and a good rinse.
This scenario was repeated for all equipment that was used throughout the day (with the sanitation part for the post-boil equipment):
USE --> CLEAN --> SANITISE
At that time, the brewery required three days of brewing per week to fulfil their orders. The regular brewing, as far as I remember, was being undertaken between Tuesday and Thursday. What Andrew and Mark were doing on Fridays was a “caustic brew”. They were going through all the stages of brewing, but using a caustic solution instead of pure water to make sure the equipment and piping are washed inside and out. This was the weekly cleaning routine. Just to make it clear no grains are used in this process – obviously.
After a well-deserved lunch, most of which was spent by microwaving Mark’s full-on Sunday roast, some trust was put in me and I got to fill some casks. The beer, ultimately served as a real ale, is not carbonated beyond what the fermentation provides. As such it does not involve force carbonation and kegs. It is a nice and easy process of pouring the beer straight from the conditioning tanks and into the casks.
Someone is going to enjoy this Goldihops very soon (Andrew left, Mark right).
Saying that, it is worth looking at the HSA experiment undertaken by boys at Basic Brewing (link), with interesting conclusions.
I don’t think Andrew liked my interrogation, as he handed me a shovel straight after, and pointed towards the mash tun. Well, someone had to do it, and I am telling you that standing in a waist-deep insulated tin full of hot spent grain, and still trying to do some work is not the most relaxing of exercises. This was followed by a good scrub and a wash with a caustic solution, and a good rinse.
This scenario was repeated for all equipment that was used throughout the day (with the sanitation part for the post-boil equipment):
USE --> CLEAN --> SANITISE
At that time, the brewery required three days of brewing per week to fulfil their orders. The regular brewing, as far as I remember, was being undertaken between Tuesday and Thursday. What Andrew and Mark were doing on Fridays was a “caustic brew”. They were going through all the stages of brewing, but using a caustic solution instead of pure water to make sure the equipment and piping are washed inside and out. This was the weekly cleaning routine. Just to make it clear no grains are used in this process – obviously.
After a well-deserved lunch, most of which was spent by microwaving Mark’s full-on Sunday roast, some trust was put in me and I got to fill some casks. The beer, ultimately served as a real ale, is not carbonated beyond what the fermentation provides. As such it does not involve force carbonation and kegs. It is a nice and easy process of pouring the beer straight from the conditioning tanks and into the casks.
Someone is going to enjoy this Goldihops very soon (Andrew left, Mark right).
My first cask. Feel like a proud parent.
While I was playing at the filling station Andrew was looking after the boil, adding the hops at scheduled times. I cannot say how much from memory, but significant amounts went in late in the boil. When the boil was over the beer was circulated through the heat exchanger a few times and then through the under-ceiling system of pipes straight into the fermenter.
There are four fermenters at the brewery which are in fact reconditioned dairy heaters. Each is capable of holding the full 10BBL batch, with full temperature control. They are slightly unusual in shape being flat, shallow, with ever so slightly conical bottom, but I was assured they work very well.
If I was yeast, I would be getting excited.
The standard practice in breweries is to target a slightly higher gravity than desired, as this allows for making an adjustment by adding some water before fermentation. Also in this case some water was added to get down to the planned gravity. In meantime Mark was preparing a yeast starter using the fresh wort. The starter was ever so slightly bigger than I got used to, prepared in a 30 litre bucket.
The yeast that is used at Kelburn brewery is a strain specific to the brewery, which has been maintained and looked after for them by an outside company since shortly after the creation of the brewery. Every now and then Andrew requests a new batch which is then used, and re-used, and re-used, and re-used… until is deemed too weak or unhealthy. Then, another new batch is requested. Each cycle like that can last up to several months.
Because the fermenters are in essence a big, stainless steel bath with a loosely placed lid, the fermentation could be deemed as “half-open”. Bear in mind this is a non-technical term entirely made up by me. Andy did not hesitate to open the lid of the other fermenter where the beer was at the peak of fermentation. More so, he says that the krausen regularly lifts the lids and comes out of the fermenter and onto the floor. There is no panic. A quick wipe and wash and everyone is happy.
Following the fermentation the beer is pumped through the pipework, and straight into the conditioning tanks. There is about 10 tanks, each capable of holding half the batch. Tanks are double skin with a chilling liquid between the walls. This allows to keep the beer in nice and low temperature of 2 degrees. The benefit of the low temperature is that the beer clears better, with remaining proteins and yeast dropping to the bottom of the tank. This is an important stage as otherwise the beer is not filtered.
Conditioning tanks.
Because the fermenters are in essence a big, stainless steel bath with a loosely placed lid, the fermentation could be deemed as “half-open”. Bear in mind this is a non-technical term entirely made up by me. Andy did not hesitate to open the lid of the other fermenter where the beer was at the peak of fermentation. More so, he says that the krausen regularly lifts the lids and comes out of the fermenter and onto the floor. There is no panic. A quick wipe and wash and everyone is happy.
Following the fermentation the beer is pumped through the pipework, and straight into the conditioning tanks. There is about 10 tanks, each capable of holding half the batch. Tanks are double skin with a chilling liquid between the walls. This allows to keep the beer in nice and low temperature of 2 degrees. The benefit of the low temperature is that the beer clears better, with remaining proteins and yeast dropping to the bottom of the tank. This is an important stage as otherwise the beer is not filtered.
Conditioning tanks.
As the beer is not filtered, and the handling of the casks is impossible to control the moment they leave the brewery, it is important to encourage the yeast remaining in the beer to drop to the bottom of the casks as quickly as possible. The moment the casks arrive at the pub they have most likely hours before they are cracked open. Normally this would not be sufficient for the beer to clear following all the travel induced disturbance. Isinglass however helps any remaining yeast in the beer to settle to the bottom of the cask, just in time, if managed properly, to allow the first pint to be clear.
I have not mentioned about bottling really as Kelburn’s beer goes predominantly into casks. Bottled beers are not the main source of income for this brewery and the bottling process has been outsourced.
I have not mentioned about bottling really as Kelburn’s beer goes predominantly into casks. Bottled beers are not the main source of income for this brewery and the bottling process has been outsourced.
Summarising, it was an amazing experience down to willingness of the people from Kelburn brewery. At the same time it showed me that we, homebrewers, don’t differ much from the commercial breweries with regards to the processes we go through, but on a smaller scale. What was however the biggest eye opener to me, was that there are things that cause sleepless nights to some homebrewers, that is including myself, that are not really worth thinking about; Hot side-aeration or air-tightness of fermenters, in my opinion, being some of them.
All in all I had a great time and I do encourage anyone to get in touch with their local brewery and maybe, just maybe you will be able to help them one way or another. In meantime, take care and see you next time.
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