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Totally Tubular

20151108 CW0A0228

Every homebrewer needs tubing/hosing as a tool for moving their wort and beer from vessel to vessel. Homebrewers use tubing for cold-side racking, for hot-side brew day transfers, and also for liquid and gas connections in their kegerators. From its simplest form of transferring a beer from one vessel into another, hose and tubing is an intricate part of the homebrewer’s toolbox. Yet comprehensive information is scarce on tubing and hosing. Here we will explore the options currently available to homebrewers, as well as the pros and cons of different materials to guide you through the choices that are currently available.

Talk the Tube and Hose Lingo

The first thing to know about tubing and hose is that they are not the same thing. While the words are frequently used interchangeably, they are actually not the same thing. The difference is that hoses are reinforced with braiding, wire, stiff plastic, or other materials. This is so that they can withstand high pressure. Tubing, on the other hand, is not reinforced, so it is only useful for low-pressure applications, such as gravity flow. There are also certain terms that most every homebrewer who is looking to invest in hosing and tubing should be familiar with before heading out to shop for any equipment.

First up is the working pressure of the hose or tube. This number is basically the maximum recommended pressure that the hose or tube operates under. If the pressure inside the hose or tube goes above the working pressure, that is not to say that failure is imminent, but rather that the hose or tube is not designed to operate normally under this type of pressure. If you’re operating a kegerator, you’ll want the working pressure of your tubing to be rated at a minimum for the highest pressure you plan to set the primary regulator.

Next is the burst pressure, which is the pressure at which that hose or tubing type will fail at a given diameter. The working pressure and burst pressure are both temperature and width dependent, so while your high-temperature tubing may have a burst pressure of 30 PSI at room temperature, that may drop off significantly at boiling temperatures. Also, thick-walled hosing can be significantly more pressure tolerant than thin walled hosing.

The last hose and tube specification to know is non-reinforced vs. braided reinforced, as I mentioned earlier. Braiding will greatly increase both the working pressure and the burst pressure of a given hosing material. Employing threads interwoven into the hosing, the strength increases manyfold. For example, using a particular PVC vinyl hosing, the difference from non-reinforced to braided reinforced means moving from a working pressure of 10 PSI to 100 PSI for 1⁄2-inch (12.7 mm) hosing.

Safety Issues Food Grade

Before we continue there are a couple of safety issues to be aware of when buying hosing and tubing. One of the most important aspects of picking out new hose and tubing is to make sure that it is made of a food-grade safe material. In the USA, look for food-safe materials that conform to FDA standards — or better yet NSF-51 listed. This ensures that the material you are using has been approved to be safe with foods by an independent agency. While it may not have the contact time of a plastic bucket, in my opinion hose and tubing can be just as important given the area of beer that is in contact with the hosing and tubing. Please make sure to give the extra time and pennies to utilize only food-grade plastics to reduce the leaching of plastics into your beer. The low pH of beer is a problem for many non-food specific hoses and tubing.

Pressure Ratings

Another potential safety issue is the pressure ratings that you will find on a lot of hoses. While this is generally of minimal significance to homebrewers, it is still something to keep an eye on, especially if you work with a pump and will be running near-boiling liquids through the hose. For example, if you do find hosing that is rated to 50 PSI, you should take that number with a grain of salt. Often the ratings are for the hosing at room temperature and can sometimes be for the smallest diameter hose available. Generally the pressure ratings are inversely related to both inner diameter of the hose and to the temperature of the fluid/hose temperature. So the higher the temperature and the wider the inner diameter, the lower the maximum working pressure for that hose material. Meanwhile wall thickness and pressure rating are directly related. Increase the wall thickness of a given material and the pressure rating will also increase. All that said, if you choose wisely and safe practices are employed, pressure ratings for hoses should never come into play. But be smart; using a 1⁄2-inch (13 mm) non-braided vinyl hosing rated to 8 PSI (at room temperature for an unknown diameter hose), moving 180 °F (82 °C) sparge water through a pump maybe asking for a potentially dangerous blow-out. I personally have had silicone tubing burst on me when a RIMS (recirculating infusion mash system) tube was accidentally turned on without PID (proportional-integral-derivative) control. I was lucky and was only left with a ringing ear and a hose that was 6 inches shorter than before — and I was also lucky to be almost 10 feet (3 m) away from the explosion.

Cold-Side Transfer Tubing

The simplest form of tubing is that which is found in most starter homebrew kits, the vinyl transfer tubing that accompanies most racking canes. Generally a food-grade vinyl is preferred because of cost, flexibility, and ease of cleaning. There are tons of others options that homebrewers can utilize, but nothing will be more cost-effective than vinyl.

First and foremost if you’re out buying your own tubing, you need to make sure that the vinyl is food-grade as mentioned earlier. Most types of vinyl tubing I’ve come across at hardware stores are not food-grade and could be potentially dangerous over the long term. Food-grade vinyl is a great type of tubing for transferring beer or wort once it is cooled to below about 100 °F (38 °C). While I’ve seen this material rated to be safe to temperatures up to 175 °F (79 °C), the vinyl becomes very soft and pliable, causing kinks that can be extremely problematic and even dangerous when trying to transfer hot liquids. On the plus side, food-grade vinyl is tolerant of the low pH of finished beer.

Another pitfall of vinyl tubing is its memory. Once vinyl tubing has been coiled, it seemingly can never be straightened out again. This causes problems with a curling at the ends, which I find problematic when I want the transfer hose to sit at the bottom of the receiving vessel for transfer. The curl prevents the exit point from resting at the bottom of the carboy or keg. Opting to use silicone tubing will calm your nerves, but the price tag for silicone is quite a bit higher for not hearing the gurgle of beer mixing with air for a brief period. Silicone is food-safe, making it a good option for anyone who may want to step up their cold-side transfer hosing. See Figure 1 for more information.

Hot-Side Transfer Hosing/Tubing

If you are looking to purchase hosing to use on brew day, you have several options — but expect to pay quite a bit more than you will for cold-side applications. The first option to consider is braided vinyl hosing. While it may be more cost-effective than its silicone counterpart, the downsides (in my opinion) greatly outweigh the cost benefits; mainly that vinyl is only temperature graded to a maximum 175 °F (79 °C), but often even less. This may be okay at mash temperatures, but anything beyond that and you’re looking for problems.

Silicone is probably the most popular material for hot-side (brew day) hosing among homebrewers. Rated upwards of 500 °F (260 °C), it’s great for hosing connected to a mash tun undergoing direct-fired recirculated mashing. Just be sure that the hosing is protected from direct flames. Silicone’s translucent quality allows you to see if there is liquid flowing or you’ve hit a stoppage. It’s flexible, allowing you to make awkward connections without too much of an issue. So while cost is a bit of setback, the pros more often outweigh the cons. I do find in my own homebrewery that the flexibility of silicone can be great at times, but also a curse. Kinking can be a hassle with silicone hosing when operating with hot liquids (thicker-walled silicone tubing such as 3⁄16-inch walled or thicker helps avoid kinks) and the soft material is prone to gashes if not handled with care. Most common silicone tubing (width and temperature dependent) is rated to about 10 PSI working pressure with a burst pressure of about 30 PSI. If you opt to step up to the braided version (Silibrade®), that burst pressure jumps up to over 420 PSI. The braided version offers almost all of the benefits of the non-reinforced version with less kinking issues — but also a little less flexibility as well as a higher price tag.

Santoprene™ thermoplastic hosing is another fairly popular option. Temperature rated to 275 °F (135 °C), it is a good option for brew day hosing. Not all Santoprene™ is food grade, however, so make sure you are buying material that complies with FDA standards. It is easy to tell the difference in material types here as the non-food grade version is colored black while the food-grade is a manila color. The rigid wall of thermoplastic feels more like braided silicone hosing, but is far more cost-effective. Some stores will offer both thick-walled and regular- walled versions. Pressure ratings are high with Santoprene™ hosing since most diameters and wall thicknesses are rated to over one-thousand PSI for tensile strength, although I could not find a working pressure or burst pressure for this tubing material at the time of this writing. Personally I find the thermoplastic to strike a nice balance between rigidity and flexibility as it never kinks yet can find its way around moderately tight bends. But as is often the case, there are downsides to this hosing material as well. One major problem I have with thermoplastic is that it is opaque. Being unable to see what is actually happening inside the tubing can sometimes be a problem. Also thermoplastic should not be utilized near an open flame as I’ve found from experience that it will melt/burn easier than silicone tubing.

A more recent addition is PVC-free, high-temperature hosing made from TPE (thermoplastic elastomer). Similar to Santoprene™, TPE hosing is rated to 275 °F (135 °C), and has a relatively high burst pressure, about 60 PSI. On the plus side, it is flexible and the hosing is translucent, allowing you to see if liquid is present in the hose. This hose is also fairly kink resistant. With a cost similar to silicone, it is definitely worth a look. I have not used this type of hosing in my home set-up before, but it seems to be a compromise between silicone and Santoprene™. See Figure 2.

Draft Dispensing Tubing (Gas Lines)

Just like with cold-side transfer hosing and tubing, vinyl rules the roost for most gas-line tubing. Again, it’s cheap, comes in food-grade options, and is flexible. It should be thick-walled (~1⁄4-inch), allowing it to handle the elevated pressure that even soda water might require. If used properly, gas line hosing and tubing should last for years, even decades. I want to add some words here about the opaque colored gas lines that you find at many retailers. On one hand, it’s convenient for easily identifying which gas line belongs to which keg. However, I have one warning: For those like me who may have accidentally placed an uncharged gas disconnect on an overfilled keg that is fully carbonated and watch in horror as beer shoots up your gas line, you know what I mean. While that is a good time to release some expletives, I at least know I need to remove that hose and give it a thorough cleaning or just replace it. Without actually seeing that charge of beer up the gas line, who knows what would be growing in the hose in another couple months. These days I stick with the transparent tubing. If you are like me, but you want color coding, use a small piece of duct tape on the ends. Duct tape comes in so many colors these days, several rolls can unsort even the biggest manifolds. And seriously . . . who doesn’t need more Duct tape?

One other note about gas lines: If you are setting up your draft system, be sure that your barbs are all the same size. So if your gas disconnects have 5⁄16-inch barbs, make sure your regulators and any manifolds are all 5⁄16-inch. Then when you purchase your gas lines, be sure to make the inner diameter 1⁄16-inch smaller. So 1⁄4-inch tubing for 5⁄16-inch barbs. This will assure very snug fitting and help prevent hair-pulling leaks. Be sure to have very hot water on hand when putting it all together to get the tubing pliable. This is very helpful with the thick walls found in most draft lines. See Figure 3.

Draft Dispensing Tubing (Liquid Lines)

The liquid lines offer a lot more options because of the basic fact that this is the tubing that beer can be sitting in for months at a time. Beer line hosing has to be food-grade and able to handle some fairly corrosive chemicals like BLC (Beer Line Cleaner), which you should clean your lines with on a regular basis. Some recent tubing types introduced to the market possess anti-microbial properties like silver to preclude growth of unwanted visitors while others boast of the lack of diffusion of CO2 out and O2 in through the material. If you do decide to go with an anti-microbial type of hosing, you still need to properly clean your tubing on a regular basis; anti-microbials are just one added measure against the growth of bacteria and other microorganisms.

First up is super vinyl. This type of tubing is food-grade and very flexible. The cost for super vinyl is also extremely low, making it the perfect choice for a basic draft system set-up. But be sure to run BLC or PBW (powdered brewery wash) through super vinyl before your first use, followed by a quick shot of an acid sanitizer (like Star-San). This material will impart a plastic-y flavor if you don’t. It will fade with time, but it’s better to eliminate it in the first place. Vinyl also has the reputation of hanging onto flavors. If you plan on running a variety of drinks through your draft lines like flavored soft drinks or fruit-forward beers, this may not be your best choice. That said, I do find that caustic cleaners like BLC do a good job of taking care of these flavors.

Gen-X® tubing is a newcomer to the market, and along with being food-safe for use with beer, it also claims to be nearly an impermeable barrier of gases through its walls. The price point is higher than vinyl, but gives draft system owners something to think about, especially if you prefer hoppy beers where O2 ingress may be an issue or if your taps are not used on a regular basis.

Bev-Flex Ultra® is another beer line tubing that is common in the draft beer world. It has a low price point, low permeability of gases through its Glas-Flex™ liner, which also helps keep the plastic taste out of the beer, and is NSF-51 grade safe. On the downside, I had trouble with its stiffness. If you keep your kegerator lines kempt, then this shouldn’t be an issue. If you’re like me and have hoses going in many directions, this hosing may be more trouble for you than it’s worth. I’ve also read complaints about getting Bev-Flex Ultra® tubing over barbs due to its rigidity. There are other plumbing options available rather than barbs, but you need to decide if the added cost of the plumbing is worth it to you. Finally, you do need to increase your beer line length to compensate for the fact that Bev-Flex Ultra® has less resistance than most other draft tubing.

Finally there is Ultra Barrier Silver™ Antimicrobial and ClearFlo® Ag-47 beer line tubing. This hose claims to have a silver infused lining that is supposed to keep the “top four beverage spoilage bacteria” at bay. Ultra Barrier Silver™ is PVC and BPA free, while ClearFlo® is listed NSF-51 certified. The price tag for this tubing is a jump up from the other options, but if you don’t mind spending an extra couple of dollars for a level of comfort with what you are putting in your body, this is probably the choice for you. Offering nice flexibility, Ultra Barrier Silver™ is the luxury car of beer line hosing. If you’re not ready to jump on board with the silver lining, there is also regular Ultra Barrier™ beer line tubing as well, which is PVC- free, has nice flexibility, and has a lower price point. See Figure 4 for more information.

Final Notes

One problem you will discover when shopping for tubing and hose is that there is a HUGE variety. Ann Phy from New Age Industries provides insight: “There are many plastic tubing materials that can do the job of transferring the fluids involved with homebrew production. But they can have drawbacks such as cost (fluoropolymer, for example), rigidity (polyethylene), the lack of NSF listing (polyurethane), non-transparency or non-translucency (opaque colored tubing), or tubes with inner liners (inserting fittings can be difficult).” Luckily homebrew supply stores have taken a lot of guesswork out of making your decisions and have already selected some of the top options in the market. I highly recommend getting short sections of two or more different types of hosing and testing them out to find out what kind you like best for each particular use.

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Issue: January-February 2016