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EZ, Low Cost DIY Tap for 6L TAD & 3L SODA Bottles (w/Pics)

Here’s an option if you are not ready for a full kegging system. Or if you do have a keg system, and want a portable unit, or something to free up a keg that is ~ 3/4 empty.

It is a very simple construction, reliable, easy to clean, and low cost. With estimated shipping for some required parts, you could make 5 tap adapters for less than $14 each, or 10 for less than $12 each. This does not include the TAD bottles themselves ($8.50 from our sponsor, a bit cheaper direct from TAD). This works with the 3L soda bottles as well. This is less than half the cost of the TAD tap, no mechanisms to break, and can be used vertically or horizontally.

Some background: I have used this basic design for a few years on Mini-Kegs, and the tap has worked well for me. I became a bit disappointed with the Mini-Kegs themselves though. I’ve had problems with the linings failing and giving a metallic taste before I could see the defect, they are a bit of a pain to clean (not easy to drain/dry), and the construction of a hold down for the tap was a bit more involved. More details on the Mini-Kegs in this thread :


So I read up on the Tap-A-Draft systems and bottles again, and people seem happy with the bottles themselves, some reporting that oxidation was not a problem after even more than a year. I had a simple idea to apply my Mini-Keg tap to those bottles. So here is what I came up with:


Construction and parts list/sources to follow…


General Construction: A 38 mm cap is drilled out to 3/4" to hold a #4 two-hole stopper. Inserted from the ‘inside’, the stopper will hold against carbonation pressures. Then 1/4" OD tubing is pulled through the stopper holes, one for CO2, one for the beer. I terminate each of these in barbed Luer connectors, though you could do this differently. The Luers are nice as they can be ordered with either 1/8" or 1/4" barbs, they connect with a simple 1/4 twist, and are low cost. The different barb sizes allow me to interface the 1/8" ID tubing to 1/4" or 3/16" ID tubing to connect to a picnic tap, and to my CO2 line. A low cost check valve is placed in the gas line so that CO2 can be connected/disconnecting at the Luer w/o losing pressure. I’ve also used Quick Disconnects, like the ones NB sells: ... -barb.html ... -barb.html

(these are available from other suppliers in 1/8" barb sizes also - see in sources below).

A 3L PET SODA bottle cap will also work (I get 3L bottles of soda at Dollar Tree), but I prefer the molded caps direct from TAD, as they have an o-ring seal and appear to be a very robust construction, and get good reviews. Going the 3L cap route will save about $1/tap. There are lots of different options for the tap and gas lines, but I’ll first show what I’ve done to keep things simple.

How to Use: I plan to naturally carb in the TAD bottles, just as I did with the Mini-Kegs. I bought a few of the TAD pressure relief caps, but my tests showed they released at about 10 PSI, and you need about 30 PSI @ room temp to get 2.5 volumes. I primed my Mini-Kegs with about 60% as much table sugar as when bottling to be safe, and I plan the same for the TAD bottles. I’m also looking into designing a little tension gauge to monitor the pressure in the bottle. Since the 6L bottles have rounded bottoms, I just set them on an inverted large plastic jar lid to keep them upright.

Some people have reported problems with the standard caps not holding pressure from a natural carbonation and recommend either the polyseal caps, or the molded caps that you can buy direct for the Tap-A-Draft company ( ). I plan on using the molded caps going forward, but the 3L soda caps also seem to be working well for me (tested with soda water for now).

Once carbed, fully chill the bottle so you can (slowly) remove the cap w/o foaming. Sanitize the adapter, then screw it on. I’ve got a Luer connector on my gas supply (a standard 10# tank/regulator), so I set my gas pressure for serving (usually 10-15#), connect to the gas in side of the tap, and flush once or twice if you want, unscrewing the cap a bit to release pressure.

I keep my beer in a regular, spare kitchen-style fridge, and I don’t have gas lines running in/out. So I just open the fridge, connect that gas line, open the gas valve, and pour. Once there is some head space, you won’t really need to connect the gas for every pint, you can push several pints w/o any significant pressure drop. Then disconnect the gas line and close the fridge. Obviously, you could keep this connected if you have a gas line inside the fridge. I prefer to disconnect and shut off each time so a leak somewhere in the system won’t drain my CO2 supply.

That’s about it. If you want to serve with the bottle on it’s side, you might want to add a stainless steel nut on the end of the dip tube to keep it at the bottom. A 1/2" SS nut can be screwed on over a slit piece of the 1/8" ID tubing over the end of the dip tube. I keep mine upright, so I skip this.

I’ll add notes on construction details to the next post… -kenc

Detailed Construction (Molded Cap shown) -

Step 1 - Drill the Cap - There is a raised cylinder shape in the inside center, so I drilled a 1/8” pilot from the inside through (I used a piece of 1/8” x 1/4 hose in a stiff poly 3/8” OD tube to help center the 1/8” bit), then drilled a 3/4” spade bit from the top. Drill slowly and lightly, the plastic seems soft and grabs the drill, and maybe melts easily. But it drilled pretty cleanly. Clean up any rough edges with some sandpaper on a dowel, and with the dowel itself.


Step 2 - Insert Stopper - Push the #4 two-hole stopper into the hole from the inside. Pull and push until it extends about 3/8” out the top. Get the stopper in the cap before inserting the tubing into the stopper, this makes it easy to get the stopper seated into the cap. In order to help keep the liquid tube pointed to the ‘foot’ side when serving on its side, screw the cap onto the 6L bottle, and turn the stopper so the holes align vertically with the bottle on its feet.

Step 3 - Insert Tubing - I use ~ 24” for the liquid side, this seems to give me a good pour. For the gas side, you only need ~ 3” on the inside, and a few inches on the outside, but I make it ~ 12” on the outside so I can have the bottle stand vertical in the back of the fridge and have easy access to supply CO2.

Swipe some diluted dish soap into the stopper holes and on the end of the 1/8” x 1/4” tubing. Insert the gas tubing into the ‘top’ hole, and pull it through ~ 6”. Pull the liquid tubing through the ‘bottom’ hole, about half way. Now rinse off the soap, and pull the tubing back and forth a few times as you rinse it to scrub any soap out of the stopper holes. To finish, I have 3” gas tubing inside, and 13” liquid tubing inside. Finish with the natural coil of the liquid line pointing “down” (out), so that it will go to the ‘bottom’ of the 6L bottle when on its side.

To keep from pulling the tubing out of the hole when you do this, it helps to grab the tubing and lever your hand against the stopper so you are only pulling an inch or two at a time.

Step 4 - Terminate ends - On the gas side, insert the check valve with the arrows pointing to the cap side. Then add ~ 1” of 1/8” ID tubing to the input side of the check valve, and insert a 1/8” hose barb Luer onto that end (I use a female Luer here). Terminate the liquid end in a 1/8” hose barb Luer (I use a male Luer here). I attach a picnic tap with a mating 1/4” Luer and a short piece of 3/16” ID tubing.

Optional, but in order to provide a better gripping surface for connecting and disconnecting the Luers, before I attach them, I first slip ~ 1” long piece of 3/8” x 1/2” tubing over the gas and liquid tubing, followed by a ~ 1/2” long piece of 1/4” x 3/8” tubing. Then attach the Luers, slip the 1/4” x 3/8” tubing over the barb, flush with the Luer body, then slip the 3/8” x 1/2” tubing over that assembly, and over the Luer body. An open end wrench can help get these seated.

Parts List with prices and shipping estimates, and some idaeas on CO2 sources in next post - kenc

Parts List with prices and shipping estimates:

[attachment=0]Cost Summary-TAD DIY Tap-rza.png[/attachment]

Part Sources -

#4 Twist-It rubber stoppers -

Stopper 5 pk $3.99
Stopper Shipping $7.50

Luer connectors, McMaster Carr #'s follow - you can sometimes find these on Amazon, but availability is spotty. I have some of each type on hand to make it easy to adapt back and forth, so I built my taps with a consistent flow using Males as outputs, Females as inputs, but you could stick with just Female 1/8" and Male 1/4" to reduce the number of styles to order.

Barbed, Female Nylon
Tube ID Pkg. (10)
1/8" 51525K213 $3.51
1/4" 51525K216 $3.86

Barbed, Male Nylon
Tube ID Pkg. (10)
1/8" 51525K123 $3.96
1/4" 51525K126 $4.43

These parts from Tap-A-Draft direct ( ):

Molded Cap   $1.73 

And the bottle itself, from NB or TAD direct:

6-Liter Brown Bottle comes with standard cap.   $6.83

I got these from US Plastics, shipping was ~ $7 for these small, light parts.

64046 Each $0.79 1/8" PP Standard Check Valves << I use on gas side of tap
64048 Each $0.73 1/4" PP Standard Check Valves << You might want on your gas source?

Or if you just want to adapt from 1/4" or 3/16" ID line to the 1/8" ID hose (not certain these are food grade?):

64275 Each $0.46 Black Nylon Reduction Couplers 1/4" x 1/8" Tube ID
64370 Each $0.53 Natural Polypropylene Reduction Couplers 1/4" x 1/8" Tube ID

I buy the 1/8" x 1/4" PVC tubing (7001P) from a local True-Value HW store ~ $0.27/ft, it is rated food grade for beverage and is made by

SAMAR CORP ... atalog.pdf

7001P - Samar’s versatile Clear Vinyl Tubing can be used for beverage dispensing, potable water, laboratory tubing, drain lines, water transfer, and numerous low pressure applications. It is light weight, yet tough and abrasion resistant. The CVT’s PVC compound is in compliance with FDA CFR TITLE 21 requirements, and meets USDA, 3A, and NSF51 criteria.

Alternate Parts:

You could use these QDs from Colder Product Corp. in place of the check valve and Luer on the gas side. Here are the PNs from US Plastics for all the combos of male/female 1/8" and 1/4" hose barbs:

64166 In-Line Hose Barb Insert
PMC Series Acetal Shut-Off Insert Hose Barb Fitting 1/8" Flow; 1/8" ID Each $5.52

64154 In-Line Hose Barb Body
PMC Series Acetal Shut-Off In Line Hose Barb Fitting 1/8" Flow; 1/8" ID Each $5.77

64168 In-Line Hose Barb Insert
PMC Series Acetal Shut-Off Insert Hose Barb Fitting 1/8" Flow; 1/4" ID Each $5.52

64155 In-Line Hose Barb Body
PMC Series Acetal Shut-Off In Line Hose Barb Fitting 1/8" Flow; 1/4" ID Each $5.77

And TAD also sells a Mini-Keg adapter, which might be able to be used with this tap design, but I have not tried it and don’t know:

Adapter to use Tap-A-Draft dispenser with a 5-L mini keg. Adapter fits into standard bung on mini-keg. Bung not included. $7.76

Note on CO2 source: If you don’t have a full CO2 tank and regulator, there are a couple options.

Option 1) Some people use the little trigger operated Soda Keg CO2 Charger, you’d just need to add a tire-stem (air tank valve at my local HW store) to the gas in-line. Note that these are not regulated, so I think they are somewhat risky - you need to shoot just enough to increase the pressure for a good pour. I’ve never used them, so cannot comment. But they are pretty cheap and portable. ... arger.html

Option 2) I’ll put up a thread and a link later, but I’ve got a DIY design to use with a paint-ball tank. Less than $10 and easy to construct, and while it does not use an actual regulator (which is what makes it cheap), it is basically self-regulating, and very easy to pump a bottle back up to serving pressure (10 - 15#), and can get to 30# for soda water. Paint-ball tanks are ~ $20, and refill is about $4. Much cheaper than using cartridges, though the tank will need to be replaced or hydro-tested after 5 years.


Hi, thanks for documenting and posting this solution.

I am looking to make something similar. However I would like to have my bottles resting horisontally, like in the standard TAD setup. Is it possible to have them standing in your setup? I guess not since you have them standing in the picture, but what would it take to make a system for horisontal bottles?

[quote=“otveit”]Hi, thanks for documenting and posting this solution.

I am looking to make something similar. However I would like to have my bottles resting horisontally, like in the standard TAD setup. Is it possible to have them standing in your setup? I guess not since you have them standing in the picture, but what would it take to make a system for horisontal bottles?[/quote]

You’re welcome. I just finished off a couple of 3L ‘kegs’ of beer that I naturally carbonated, and used CO2 just to push out & serve the beer. It worked really well. I’ll start tapping the 6L today. I took two of them to my beer club that were a bit less than 1/2 full and the CO2 in the headspace was plenty to push the rest of the beer for the evening, so I didn’t need any portable CO2 setup.

I felt confident enough to buy 14 more of the 6L jugs, and just ‘kegged’ two beers yesterday. It really went fast, I just added 2TBS + 1 tsp of dry table sugar to each 6L jug, and 1 TBS + 1 tsp for the 3L. Then I filled from the bottling bucket with just a hose (no gravity/spring tip), to about 2.5" down from the neck (that gives the same 5% headspace that I measured on a 12 oz bottle filled with a bottle filler). Flows fast and I got 2 of the 6L filled, 6 12-oz bottles (I might skip these in the future), and 2 3L jugs, the last partially filled. EZ.

I’m using the molded caps that I got direct from the Tap-a-Draft mfg (link above). I think these are the best. The poly-seal ones did not seal on my 3L PET jugs.

Anyhow - about using them horizontally - Should be no problem at all. Though you need to know that any leak at the cap will result in liquid leaking, which is messier than just a CO2 leak. You might want to keep them in some kind of tub until you know there are no leaks in your system. If you naturally carb, I’d leave them upright so that’s not an issue.

The only thing you probably need to change is to shorten the dip tube a bit from what I show so it does not hang up on the bottom of the jug. If you can’t get the natural curl in the tube to reliably point down to the ‘bottom’ (the side when it is upright), you can buy a couple stainless steel nuts at the hardware store. Get them a bit larger than the 1/4" OD of the dip-hose, and cut a 1" piece of hose, slit it, and you can get the nut to screw onto the end of the tube - the slit hose will take up the extra space. Cut it to give a snug fit. The nut (or two) should provide enough weight so that gravity pulls it down. The nuts have rounded edges, so I don’t think they will scratch the jug, though you could slip a short piece of tubing over the nut if that is a concern. You can also try to form your own curl in the tube by dipping it in just under-boiling water, then let it cool in the shape you want. But I suspect you will need the weight (which is what Tap-A-Draft uses).

Let me know how it goes. I’m really happy with this so far. Cleaning and draining the 3L and 6L is cake compared to those mini-kegs. Filling is easier too, since you can easily see the level.


Fantastic! I had the same problems with a metallic taste from the minikegs and have already purchased the TAD bottles and caps. I will be picking up some #4 stoppers and cutting the caps to fit today!



FYI, I just published a thread for a cheap DIY Paintball adapter as an alternative to a full sized (5, 10 or 20#) CO2 tank and regulator. Could be used as a main CO2 source, or just for portable use if you already have a CO2 tank and regulator. Might be a nice option for someone just getting started with this set up.



Guessing these images got lost in thr upgrade also. That a shame, looks like some more great information.

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