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BetterBottle® Carboys: Suggestions For Use

These suggestions assume the user is familiar with general winemaking and beer brewing techniques and precautions.



Better-Bottle carboys have wide (4.5 cm [1.77"] ID), uniform necks, so they are easier to fill than glass carboys. Also, sudden temperature changes will not cause Better-Bottle carboys to crack. However, do not fill Better-Bottle carboys with liquids that are above 60°C (140°F) It is a matter of safety! It only takes about 6 seconds for liquids at that temperature to burn skin severely. And liquids above this temperature can damage the carboys (see the Technical  page for materials information). Before filling carboys that are equipped with a Racking Outlets, take the following steps:
  1. See the Valve/Adapters page to review the installation and details of the High-Flow valve and Racking Adapter.
  2. Be sure the High-Flow valve is fully closed.
  3. Turn the Racking Adapter so the stem is angled slightly downward to prevent sediments from lodging in the stem.


Better-Bottle carboys are safe and easy to handle they are unbreakable, they are light, they have textured grips, and their strong necks are designed for handles. Handles make moving filled carboys a great deal easier and Better-Bottle recommends several types. The reports of handles cracking off the necks of carboys refer to glass carboys, not Better-Bottle carboys. See the Handles page for specific information about handles.


Standard #10 rubber stoppers and vinyl, double-port, pop-on caps fit the necks of Better-Bottle carboys very well; however, these closures are likely to impart, or carry over, flavors, and they tend to leak if they are at all rough. Better-Bottle offers a closure made of non-porous PET/PBT that washes easily and does not transfer flavors. This closure uses Viton O-rings to create reliable seals. See the Closures page for specific information about closure options and use.


Better-Bottle carboys are used for primary fermentations as well as secondary and tertiary fermentations. It is especially easy to mix and de-gas with Better-Bottle carboys (See below). However, many wine and beer kit manufacturers recommend using pails for primary fermentation and Better-Bottle offers a Pail Adapter for the High-Flow valve, so racking from a pail can be as convenient as racking from a Better-Bottle carboy (See the Valve/Adapters page). When a primary fermentation is performed in a Better-Bottle carboy and it is vigorous and foamy, a 3/8" ID X 1/2" OD or 1/4" ID X 3/8" OD hose can be attached to the carboy closure and used to vent the foam into an overflow container or sink. Be sure to leave a clean air gap between the end of the hose and the liquid level of the waste. As soon as foam is no longer rising to the top of the carboy, replace the hose with an air lock, preferably a Better-Bottle DryTrap, and complete the fermentation. See the DryTrap page for specific information about servicing and operating DryTrap air locks.

In order to minimize the number of times a carboy is opened during fermentation, Better-Bottle suggests placing a hydrometer in the carboy for the duration of the fermentation and, if the carboy is equipped with a Racking Outlet, drawing test samples through the Outlet. If solid items (e.g., oak chips, elder berry, etc.) are added for flavoring, Better-Bottle suggests placing them in a winemaker's tea bag. These items can end up floating well above the sediment and the tea bag will prevent them from being transferred during racking.


Placing a tennis ball in the punt space under a Better-Bottle carboy makes vigorous swirling nearly effortless. It is important to swirl carboys on a smooth, or soft, surface that will not scratch the bottom of the carboys.


Racking or transferring wine or beer can be done traditionally with plain Better-Bottle carboys; however, the process is much simpler and more convenient when the Better-Bottle carboys are equipped with High-Flow valves and Racking Adapters. These Outlets make oxygen-free and low-oxygen, closed-loop racking extremely easy a major advantage compared to siphon racking. See the Valve/Adapters page for detailed information.

SECTION A: Arranging the Components

  1. The bottom of the full carboy to be racked, the input carboy, should be well above the neck of the empty carboy, the output carboy. If the input carboy is placed on a 1 meter (39 inches) high counter and the output carboy is placed on the floor, 20 liters (5.3 gallons) will transfer by gravity in about five minutes. The input carboy can be placed on a higher surface for faster racking, but racking too quickly can disturb sediments.
  2. Rotate the Racking Adapter of the input carboy to position the opening of the adapter's internal stem well above the sediment layer.
  3. Rotate the Racking Adapter of a sanitized output carboy so the opening of the adapter's internal stem is pointed downward, but not quite straight down.
  4. Using an appropriate length of 1/2" ID hose, prepare a sanitized Transfer Hose to connect the High-Flow valves of the input and output carboys together. The Transfer Hose should be just a little longer than necessary to make the connection.
  5. If there is any doubt that the outlets of the High-Flow valves are clean, take a moment to rinse and sanitize them. The valves can be easily rotated, so it is easy to sanitize them with a small squirt bottle and a sponge or cup to catch the drips. Rotate the outlets of the valves downward again to drain out any sanitizing solution.
  6. Connect one end of the Transfer Hose to the output carboy's valve and open the valve.
  7. Leave the other end of the Transfer Hose disconnected until a later step, but keep it clean.
  8. The next steps depend on whether or not racking will be performed under oxygen-free or low-oxygen conditions
    1. Low-Oxygen Closed-loop racking will greatly reduce contact with air, even without purging. However, purging can be easily accomplished without the need for pressurized tanks of gas and pressure-reducing regulators by using dry ice (see below).

      1. Refer to the schematic connection of the carboys above. To rack under low-oxygen conditions, skip step "A", the purge step.
      2. Using a 90 hose barb adapter for the closures of both the input and output carboys and an appropriate length of 1/4" ID hose, prepare a clean Pressure Balancing Hose to connect the closures of the input and output carboys together.
      3. Insert the 90 hose barb adapters into the closures.
      4. Proceed to section "B", Beginning the Transfer.
    2. Oxygen-free Purchasing or renting a tank of pressurized gas and a pressure-reducing regulator represents a modest, but significant, expense; however, dry ice is solid CO2 and is readily available from ice cream shops and many supermarkets. Before using dry ice, learn about handling it safely and follow good safety practices.Sixty grams (~2 oz) of dry ice, a chunk about the size of a large standard ice cube (3.5 cm X 3.5 cm X 3.5 cm), will sublime (i.e., evaporate) to produce approximately 45 liters of CO2, enough to purge a closed-loop very nicely. The dry ice can be broken up and placed in a relatively small, wide-mouth, soft plastic bottle, equipped with a closure connected to a length of 1/4" ID hose. Do not use glass, metal, or rigid plastic bottles and be sure pressure cannot build up!To increase the rate at which the dry ice evaporates, the bottle can be warmed gently. Dry ice should not damage Better-Bottle carboys; however, Better-Bottle recommends that dry ice not be placed directly into the output carboy, because commercial dry ice may contain solid contaminants (e.g., dust, bits of paper, etc.)

      1. Refer to the schematic connection of the carboys above.
      2. Using a 90 hose barb adapter for the output carboy closure, a "T" hose barb adapter for input carboy closure, and an appropriate length of 1/4" ID hose, prepare a clean Pressure Balancing Hose to connect the closures of the input and output carboys together and to connect to a source of purge gas (i.e., CO2, N2, Ar, etc.). Be sure to have a means for closing off this hose when purging is complete. If the source of purge gas is not equipped with a positive valve, install a valve (a pinch clamp would suffice).
      3. Connect the source of purge gas to the Pressure Balancing Hose and start the gas flowing. A flow rate of about 10 liters per minute is ideal, but lower flow rates will also be very effective. Always work in a well ventilated environment and bear in mind that heavy gases, such as CO2 may pool in low areas when there is inadequate ventilation.
      4. Insert the 90 hose barb adapter into the port of the output carboy's closure and the "T" hose barb adapter into the port on the input carboy's closure. Confirm that gas is flowing freely through the empty carboy and out the open end of the Transfer Hose.
      5. After sufficient time has elapsed to adequately purge the air from the empty container, close the valve (or pinch clamp) in the section of the Pressure Balancing Hose between the source of purge gas and the input carboy.

SECTION B: Beginning the Transfer

  1. Connect the open end of the Transfer Hose to the outlet of the input carboy's High-Flow valve and open the valve. As the liquid flows it should push any gas ahead of it and out of the hose. If the liquid does not flood the hose, but streams down the wall of the hose, pinch the hose at various points to coax the gas out. When gas is trapped in the transfer hose, the transfer will take longer.

SECTION C: Completing the Transfer

  1. As the level of the liquid in input carboy begins to approach the open end of the stem of the Racking Adapter, turn the Adapter so the open end of the stem is as close as it can be to the sediment layer without drawing in sediment. The rate of flow can be slowed to recover as much of the cleared wine or beer as possible without disturbing the sediment by partially closing the High-Flow valve.
  2. When the transfer is complete, rotate the stem of the input carboy's adapter until it is well above any remaining liquid.
  3. Close the output carboy's High-Flow valve and salvage the liquid remaining in the Transfer Hose (25-30 ml).

    1. Insert a DryTrap in the output carboy's closure and apply light pressure to the shoulder of the output carboy for a moment and release the pressure. Compressing the carboy will force gas out through the DryTrap and create a slight vacuum inside the container.
    2. Carefully open the output carboy's High-Flow valve until the liquid in the hose is sucked into the carboy. If some liquid remains in the hose, repeat these last two steps.


Better-Bottle High-Flow valves are designed so that a standard 3/8" bottling stem will fit into the outlet, making it convenient to bottle and rack at the same time without any pumps or siphons. Contact with oxygen can easily be minimized by maintaining an inert gas blanket over the wine in the Better-Bottle carboy and flushing each bottle with the gas just before it is filled.

Cleaning / Sanitizing

Better-Bottle carboys are more easily washed and sanitized than glass carboys, because Better-Bottle carboys are so light weight and the special PET from which they are made is non-porous and hydrophobic. Hot water, a good bottle cleaning detergent, and some soaking will separate solids and films from the walls of Better-Bottle carboys without the need for brushing. Better-Bottle is not aware of any detergents and sanitizers, used in home winemaking and beer brewing, that damage Better-Bottle carboys and fittings when used according to their manufacturer's instructions. See the Technical page for specifics. It is rarely necessary to remove a Racking Adapter from a carboy or a Pail Adapter from a pail in order to clean and sanitize them. Soaking a carboy in a hot solution of detergent is an easy and extremely effective way to loosen stubborn contamination a carboy brush is rarely required.

Abrasive scouring pads and cleansers should never be required, or used. If a carboy brush is required, use a soft brush with no exposed metal components.

Copyright © 2004, BetterBottle Div. High-Q, Inc. All Rights Reserved.
BetterBottle is a trademark of High-Q, Inc.