Jacketed, Cold Room or Bag
This post is on brewery serving tanks, is part three of our cellar vessel series here at Build Me A Brewery. Serving tanks appear to be making a comeback, as I’m seeing more of my clients exploring this option.
I’m currently discussing the use of serving tanks with a client in South East Asia. They’re looking at using the newer bag system, a great option to consider if planning a brewpub.
CAPTION: Serving Tank with Bag in the UK (credit: www.paulmueller.com)
In this article on brewery serving tanks, we’ll look at the three main options open to most breweries:
- Jacketed serving tanks
- Single wall serving tanks in a cold room
- Serving tanks with bags/liners
As I say, bag tanks which we’ll look at later, are a newer option open to craft breweries. They’ve been available in Central Europe for some time, but now finding wider recognition in Western Europe, Asia and the US.
Still, there aren’t many manufactures of this style of tank. Puls, only a small number of breweries operating with them. The biggest debate when it comes to brewery serving tanks currently is…
“Which option is best…jacketed tanks or single wall tanks in a cold room”
They both have their advantages and disadvantages; we’ll start by exploring jacketed serving tanks.
Jacketed serving tanks are double-walled, with a cooling coil between the shells. This coil has glycol passing through it, which chills the beer. You can set the temperature you’d like to store the beer at, using the control panel.
CAPTION: Jacket Tank with Double Shell and Glycol Cooling | FV Temperature Control Panel
Usually, the beer is kept at temperatures between 0 – 4°C. The cooling will turn on and off as needed automatically, by a solenoid connected to your cellar tank control panel.
These vessels are placed in a cellar, at room temperature. Unless, the room gets very hot or cold, then air conditioning maybe needed.
Advantages of Jacketed Tanks
Each Vessel Can Be Individually Set
Each tank can be set at its own temperature. So, some beers like a stout, can set a little warmer. Some beers are best served warmer to bring desired flavors to the fore.
Chilling is More Efficient
When using glycol, the heat transfer efficiency is higher than using cold air. The net effect is you’ll use less energy, to chill the beer inside the tank. Plus, cooling will be quicker too.
Furthermore, cooling is more “directed”, you’re chilling the beer inside the tanks only, not the air around the vessel as well. One more item to note; these tanks are insulated with rock wool or pourable/expanding polyurethane within the jacket, to be even more energy efficient.
CIP (Clean in Place) is Easier
When running your CIP process, on a jacketed serving tank. Brewers use hot caustic to remove sediment.
Using hot chemicals in a cold room on a single wall tank, will raise the ambient temperature. Furthermore, the caustic gets colder the longer the CIP runs for.
Thus, losing its wetting power and cleaning efficiency. This isn’t an issue with a jacketed tank, as you turn off the cooling when cleaning the vessel.
You also have more room to work in, compared to running a CIP on a serving tank in a cold room. Plus, most cold rooms don’t have trench drains, making drainage an issue.
With jacketed tanks in a cellar room, you’ll most likely have trench drains. Plus, a pitched floor to work with. Lastly, you’re not working in the cold, when cleaning a jacketed tank.
Choosing a jacketed tank allows you to have a multipurpose vessel. These tanks can be brite beer tanks (BBT’s) or maturation vessels. I like having BBT’s in a brewery.
Let me give you an example, I’m currently running a small production facility and we don’t filter our house IPA. We do use finings (SB3 at around 80ml per HL) though, after the beer is chilled to 10°C, in the fermentation vessel.
We then recirculate the beer to ensure the SB3 is mixed in, then leave it for a few days to clear after chilling to 2°C. Now when kegging direct from the FV we’ve fined into, we sometime get issues with turbidity and sediment towards the end of emptying the tank.
However, if we move the beer to a BBT and let it settle for some more time. We generally don’t have issues with sediment and turbidity. This is because, we aren’t pulling sediment or yeast from the side of the tank, as we’ve transferred it to a “clean” tank (BBT).
It’s the same if we add fruit purees towards the end of fermentation. Then letting the fruit ferment out. If we take the beer direct from the vessel, we’ve added the puree too. It can lead stratification, with some packaged beer having more fruit in it, than others.
However, if we move the beer to a BBT, and package within 48 hours of the transfer. We get a properly homogenized mix, and all packaged beer is the same. Brewers aim for consistency, when producing beer.
Fermentation in an Emergency
Furthermore; in a pinch, you could in theory, ferment beer in a jacketed BBT. As you can regulate temperatures. It’s not ideal, but it’s an option. As I say jacketed tanks serve many uses.
A tank in a cold room is often difficult to access, making it harder to keg or package from, when compared to a jacketed tanks in a normal cellar. Plus, in a cold room the temperatures are usually higher (>=4°C), compared to a jacketed tank (1 to 2°C). So, foaming could be an issue.
Disadvantages of Jacketed Tanks
The Whole Tanks Can’t be Chilled
Most jacketed brewery serving tanks aren’t jacketed all the way to the bottom. Especially, with a flat-dish-bottom. Meaning below a certain point (a small portion of the tank), the beer isn’t being chilled.
This usually isn’t an issue. As a tank, with beer below a certain level, is mostly likely kegged or packaged off. Then refilled with another beer.
Higher Initial Purchase Price
Compared to single wall serving tanks in a cold room, jacketed serving tanks are more expensive. Yes, you have to pay for the cold room, to house single walled tanks, but still, if you’ve several tanks the overall costs are high.
As we’ve said before, jacketed tanks offer more efficient cooling. These vessels only chill the beer, not the air around the tank. Jacketed tanks use less energy, and so have cheaper running costs.
Jacketed Brewery Serving Tanks Conclusions
These vessels are multi-purpose, have low ongoing running costs and easier to carry out regular CIP protocols on. Yes, the upfront costs are higher. It often simply comes down the preference of the brewer.
Brewery Serving Tanks in A Cold Room
As we said previously; serving tanks kept in the cold room are single wall vessels. All these tanks are at the same temperature because, they are in the same room. The beer inside these tanks is drawn from the bottom of the vessel, direct to the taps at the bar.
In brewpubs, the tanks are usually placed around the sides of the cold room, with raw materials like hops and yeast stored in the center for easier access.
Why do breweries (well brewpubs and tap room really) choose this style of tank?
Advantages of Cold Room Serving Tanks
As mentioned earlier these tanks a single shelled. So, cheaper to fabricate and buy compared to jacketed vessels. They don’t have any form of insulation or internal coils to chill the beer inside.
Serve the Whole Tanks
With these vessels being inside a cold room, the beer inside is kept at the desired temperature till the tank is empty.
However, in the real world, when a tank reaches 25% capacity, the remaining beer is usually kegged off. So, the tank can be used for another beer.
Tanks only partially full in a brewery are being underutilized. It’s not the best of use of the equipment. It’s best to keg off the remaining beer, fully refilling the tank with another beer.
Disadvantages of Cold Room Serving Tanks
If all vessels are in the same room, they’re at the same temperature. Now, if you want to serve one beer warmer, say an imperial stout. It’s not possible.
If the beer is in a jacketed tank, the beer can be served at any temp you’d like. As the temperature is set on the control panel.
When a vessel is in a cold room, there are a few issues:
- When you CIP a tank, with hot caustic at a 2% solution at around 75°C. The tank is in a cold room, it’s hard to maintain the caustic at a high temperature. It loses its wetting power and cannot clean as well.
- Using hot chemicals in a cold room can raise the ambient temperature. Plus, you’re opening and closing the door more than usual. You’ll raise the ambient temperature of the whole room…which is less than ideal.
There are chemicals which are designed to clean at lower temperatures, but they’re more expensive. Plus, you’ll need to carry another chemical in your brewery.
- In a brewery drainage is important. In general; drainage in a cold room isn’t trench drains. This’ll make CIP more difficult. Whatever SOP’s you have, they’ll be more convoluted than when using a jacketed tank, in a normal room with trench drains nearby.
- You’re working in the cold…I don’t like working in the cold that’s for sure.
Cold Room Space
In breweries cold room space is at a premium. Serving tanks take up a lot of room. Furthermore, cold room efficiencies can be reduced the bigger a room is; if it’s not full.
Cold Room Brewery Serving Tanks – Conclusions
The initial costs of a single wall tanks are less than those of a jacketed tank. Still, do they make sense financially? We ask because the cost of chilling a cold room, over using jacketed tanks are higher. As the cooling is less efficient.
However, before we make conclusions, finishing this article. We should look at the third option. Tanks which using bags/liners.
Brewery Serving Tanks with a Bag
This is a newer option, which has been on the market for a while. More brewers are looking at this possibility, as a viable way to store their beer to serve. Still, they aren’t many equipment manufacturers offering this type of tank.
A project I’m involved with, in SE Asia, is looking at these tanks. They’ll likely be sourced them from the Czech Republic. I only know of a few manufacturers offering this style of vessel, with none of them in Asia.
These tanks can be kept cool by air in a cold room, or chilled with cold water. It’s a bit like jacketed and non-jacketed tanks. These tanks offer several advantages.
These bags are mostly made with many copolymer layers, which means the beer is well protected, reducing risk of contamination. The bags keep oxygen out and the beer stable and fresh.
Use only Air Not other Gases
When serving beer, you usually need to push the beer with CO2 (carbon dioxide) or mixed gas (nitrogen and carbon dioxide). If beer comes into contact with oxygen, it’ll become oxidized and spoiled.
However, if the beer is in a bag, you can use non-filtered compressed air. It offers huge cost savings. As you don’t need to use any form of inert gas to serve the beer.
As the beer is in a bag, it doesn’t physically touch the tank itself. You don’t need to run a CIP using chemicals. Most of the tank manufacturers say, simply rinse tanks out, once a month with water using a hose. In reality you’ll give the tank a rinse, once the tanks is empty.
Quick Bag Change
So, in effect, all you have to do between beers fills is:
- Depressurize the tank and open it up
- Take out the old bag
- Cut the corner of the bag and drain out any leftover liquid
- Give the tank a rinse with water using a hose, and drain
- Put in a new bag
- Fill with beer
- Pressurize with compressed air and serve
It’s quick, efficient and much safer. As you’re not using chemicals and other gases like CO2.
Now some of the companies supplying these tanks claim, the beer being in bags, allows the beer to taste fresher. I can see the logic, the bag collapses as the beer is drank and the tank emptied.
There’s no “air space” coming into contact with the beer. Furthermore, the copolymer layers of these liners are better for the beer than stainless steel, and potentially plastic from one-way kegs. I can’t confirm their claims, but as I say there’s logic to it.
Disadvantages of Brewery Serving Tanks with Bags
Getting the Liners and Tanks
Only a few companies offer this solution. So, depending where you’re are based; getting the bags/liners means shipping them from overseas. It shouldn’t be an issue, but still, it’s international shipping.
It’s the same with the tanks, chances are, they’ll need to be shipped internationally. So, the shipping costs increase the price. Since Covid-19, shipping prices have gone up considerably.
Still these days, with most people getting their brewing equipment from China. Shipping of brewing equipment overseas and the associated costs, are common in the industry.
The Bags Can Break
It’s rare the liners will break, but when they do, it can be pain. Here’s a quote from a brewer using the tanks with bags on Reddit:
Beer in Serving Tanks with Bags Conclusions
To be honest they’re aren’t really many downsides to this type of tank. If you’re a brewpub they’re actually a great option.
Fresher beer, less inert gas use, easy to clean and re-fill when empty. They’re super popular in Central Europe, with Pilsner Urquell, the first brewery to really use this technology commercially. However, use is now spreading to the likes of the UK, America and elsewhere.
Brewery Serving Tanks – Conclusions
Of the three most widely used options of brewery serving tanks, the best for your brewery comes down to personal preference. Serving tanks are used in brewpubs and taprooms.
If you’ve a larger system with taproom and also do some form of distribution too. Then jacketed serving tanks could be the best option. They can be brite tanks and maturation vessels too. It could mean, you move beer around less.
If you’re a brewpub only with limited room, then the serving tanks using bags can be a great use of space. As you can stack these tanks horizontally. Like the client I spoke about with a project in SE Asia.
CAPTION: You can Stack Horizontal Tanks to Save Space
People also like to use serving tanks in a cold room too, if you’ve a couple of big sellers. For example, in China, 40% of all beers sales maybe wheat beer. Then having this beer in serving tanks in a cold room can make sense.
You move the beer out of a FV, to the serving tank without needing to filter. Freeing up the FV to brew another beer. With the beer selling quickly in tanks, there’s not need for frequent changes. It’s less keg cleaning plus, less work for the wait staff as they don’t have to continually switch kegs.