Transferring from Barrel to Keg – the Bulldog

Now that I have beer in the barrels, I started to look at the different ways to transfer the beer from the barrels to the kegs.  I was going to use a pump and a hose, but remembered that when I did this from my fermenter to kegs, the beer was oxidized.  This seems to be a common issue with pump transfers at this stage on a homebrew scale.  In my research, I came across a piece of equipment called a Bulldog.

This piece of equipment will allow for a closed transfer of the beer from the barrel/fermenter/brite tank to kegs using CO2.  This is exactly what I had been looking for and I immediately started to build a shopping list.

I will say that there are two reasons I went with the 2″ Tri-Clover compatible fittings.

– The 2″ TC Clamp will fit around the stopper without modification to the stopper
– The 2″ TC Clamp will fit a Sanke keg opening, no stopper or TC Hose Barb

If neither of these are a concern to you, then go with the LESS EXPENSIVE 1.5″ Tri-Clover fittings and clamp.

From, I ordered:

1/2″ NPT x 3/8″ Tube Compression adapter SS – $14.00
1/2″ NPT Cross Stainless – $7.75
Bushing – 1/2″ NPT x 1/4 – $2.75 x2 = $5.50

From, I ordered:

2″ Tri Clover Compatible X 3/4″ Hose Barb – $14.00
2″ Tri Clover Compatible X 1/2″ Male NPT – $15.00
2″ Tri Clover Compatible Clamp – $7.00
2″ Tri Clover Compatible Gasket Silicone – $1.00 (I got 2)
Silicone O-Ring for 3/8″ – $0.30 x 2 = $0.60

And, of course, from

Control Devices CR Series Brass Pressure Relief Valve, 0-100 psi Adjustable Pressure Range, 1/4″ Male NPT – $11.96
Krome 11346 Homebrew Stainless Racking Cane With Tip (1, A) – $9.50

From my local homebrew shop,, I got

6 feet of 5/16″ tubing

Parts I already had:

Plug Adapter 1/4″ MPT x 19/32″ – $5.99
Cornelius Type keg Ball Lock Post & Poppet Female Thread Gas + liquid 19/32-18 by Happybrew – $10.49 for the set
#8 Drilled Stopper
#10 Drilled Stopper
2 Ball Lock Gas Disconnects with Swivel Nuts
1 Ball Lock Liquid Disconnect with Swivel Nut

Now that the parts were been ordered and have arrived, it’s time to build!  This is going to be a pretty simple build, with very few customizations.  It’s really just a matter of putting it all together.  Remember to use your PTFE Tape!

This transfer assembly relies on the pressure from the CO2 displacing the beer from the vessel (in this case, my barrels) and into the kegs.  From the CO2 in, the gas fills the inside of the cross and then exits down into the barrel.  This extra volume and pressure then forces the beer up through the racking cane and into the keg.  This is the same process used to dispense beer from kegs.

Here’s a basic understanding of what we’re going to build:

Note that the opening for the TC Hose Barb MUST be larger than the Outside Diameter (OD) of the Racking Cane (3/8″).  The inside Diameter (ID) of a 1/2″ TC Hose Barb is 3/8″ and therefore too small.  No CO2 will pass into the barrel.  This is why I use a 3/4″ TC Hose Barb, The ID of the barb is greater than the OD of the racking cane.

For this to work, the racking cane must pass through the compression adapter.  When I tried to do just that, this is as far as I got:

There is a ridge inside the compression adapter that does not allow the racking cane to pass completely through.  I knew this was going to be the case when I ordered the adapter.  You can get one from that does allow for the racking cane to pass all the way through for the same initial cost as the one I purchased, but it added a significant amount to the shipping cost.

3/8″ Compression X 1/2″ MNPT Bored Through Fitting

I used a 3/8″ drill bit and some WD-40 to quickly drill mine out (we’re talking about 45 seconds of drilling).

Once that was done, the racking cane slid through the compression adapter, snugly.  Since we will be passing CO2 through the assembly, snug is good.

Now that this step is complete, it’s time to assemble the Bulldog.  Wrap the bushings 4-6 times with PTFE Tape and tighten them into place on the East and West sides of the Stainless Cross:

Next, the compression adapter into the North (top) of the cross:

The 2″ TC to 1/2″ MPT goes into the South (bottom) of the cross:

I chose to place my Pressure Release Valve on the West side of the cross:

Which left the East Side for the CO2 In  adapter and post:

Next, take the threaded compression nut off the compression adapter.  There are two stainless rings inside that will not be used.  Discard them or save for another project.

Slide the compression nut onto the racking cane and roll the silicone gaskets onto the cane, as well

Once you have the racking cane to the height (depth) you want, roll the gaskets to the threads on the compression adapter

Then you can hand tighten the compression nut.  This system allows for differing depths depending on the vessel from which you are transferring.

At this point, this is what you should have:

The addition of two hooks on the end of my barrel stand make a nice storage solution for the bulldog, too!

If you are transferring from a Sanke keg, then all that is left is to add a piece of tubing to the top of the racking cane long enough to reach to OUT post on your keg.  I cut the length of my tubing to 4 feet, since this was all I needed from my topmost barrel to the OUT post on my kegs.  This is where I use the Ball Lock Liquid Disconnect with Swivel Nut.  During the transfer, remember to place the Gas Disconnect on the IN post and leave it open to allow for the air inside the keg to escape (remember displacement).  Place the 2″ TC Seal on the TC fitting and tighten the clamp around the TC fitting and the Sanke opening of your keg.

The use of the disconnect with the Swivel Nut allows for transfer into a vessel without a Ball Lock connection.  You can then use the Bulldog to transfer into a barrel, Sanke Keg, etc.  The only limit is your imagination.

If you are going to be transferring from a barrel, then the following steps are necessary.

Here is a comparison of the 1/2″ Hose Barb and the 3/4″ Hose Barb for reference:

When the 3/4″ is stacked on top the 1/2″, you can clearly see the difference in diameter:

Next, I used a 3/4″ drill bit to expand the hole in the stopper so I could slide it on to the hose barb

One thing to note, however, is that if you DO plan to transfer from a 53 Gallon barrel, you’ll need the #10 stopper to create a seal.  Thankfully, the hose barb on this TC Fitting is long enough to stack both stoppers and keep them on the barb without the need to swap them out.

Also, if you plan to transfer from a 53 gallon barrel on a regular basis, you will want a racking cane that is at least 4 inches longer than the one I used.

Of course, this is the piece that will fit into the bung hole of the barrel and create a seal for transferring the beer.  To assemble this piece, slide the 2″ TC seal up the racking cane to the TC fitting and then add the 2″ TC fitting with the stopper

Tighten with the clamp

You’re ready to transfer from your barrel!  You can see the extra diameter around the racking cane which allows the CO2 to enter the barrel

As you can see here, the first transfer was done on a 53 gallon barrel.  The CO2 was set to 8 psi and we achieved a transfer rate of 1 minute 28 seconds per gallon to open containers such as the bucket seen in this photo:

As you can see, the #10 stopper fit snugly into the bung hole of this large barrel.

The CO2 line is run behind the barrel and connected to the bulldog.  Once the line was connected and the tank was opened, I adjusted the Pressure Relief Valve to allow for the flow of beer.

For smaller barrels, the bottom stopper seals the bung hole.  Once sealed, push the racking cane to the bottom of the barrel and tighten the compression nut.

Prior to connecting the Ball Lock Fitting to the keg, use the PRV on the keg to purge all the CO2.  I connect the fitting to the Beer Out connection to fill the keg from the bottom.

This is the keg as the closed transfer happens:

The added benefit is that the GAS disconnect will act as a fill gauge for those not timing the fill of the keg.  Once full, the beer will flow from the disconnect in an impressive stream!


4 Replies to “Transferring from Barrel to Keg – the Bulldog”

  1. Have you used this to ferment in a Sanke under pressure? Curious to know if the racking arm fitting leaks pressure whilst being adjusted.

    1. I don’t have a sanke keg in which I can ferment, but I have checked all the connections for leaks while transferring. The only place that does have a slight leak is at the bung. In a sanke keg, this is a non-issue and I am confident enough that I would ferment using this.

    1. Not if I am just moving the cane up and down. The stopper at the bung is the weak point and if moved side to side, can lose pressure if you are not careful.

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