Project

Bottle Cleaning/Sanitizing Rack

Most homebrewers would agree that the better part of brewing beer at home is spent cleaning and sanitizing equipment. A lot of dedication goes into every batch and after waiting weeks for fermentation to be done you are ready for some payback. There is only one step that separates you from drinking that beer, and that is bottling or kegging. Bottling beer takes a lot of work — mostly spent cleaning and sanitizing each bottle.

Some of the most common methods for cleaning/sanitizing bottles that I am aware of are using chemicals and soaking the bottles in cleaning/sanitizing solutions, putting the bottles through the steam cycle in the dishwasher, or using a dry heat cycle in the kitchen oven.

In my experience, the first of these methods takes the most work. Bottles are dipped in cleaning solutions and you have to physically brush the insides and then rinse each bottle in preparation for sanitizing. The dishwasher method has the advantage of using wet heat, which is much more effective than dry heat in the oven, but there is the problem that the bottles have to be placed in upside down. That makes it hard to have a uniform coverage of steam deep inside of the bottle. The dry heating method in the oven works well by itself for sanitizing provided the bottles are already clean.

The bottle rack described in this project uses the oven as a source of heat to generate steam inside of the bottle for cleaning and sanitizing purposes. This enhances the cleaning power of the dry method.

The bottle rack in this project is made of aluminum sheet metal and holds 24 bottles. It can be used in two positions: drying position (bottles upside down) and steaming position (bottles upright). I chose 24 bottles to make it easily portable, and because that is the number of bottles that come in a case. The reasons to use aluminum for its construction are several: It does not corrode easily in high moisture environments, it is lightweight, it withstands high temperatures, it does not need painting (so there is no risk of toxic fumes) and it is easy to work with (as opposed to stainless steel).

To use this bottle rack, I add approximately 50 milliliters of water into every bottle and then put it in the oven for one hour at 250 °F (121 °C) so the bottles are steam cleaned and sanitized. The rack makes it easy to transport the bottles into and out of the oven once they have cooled. The time and temperature I leave the bottles in the oven could probably be adjusted to a higher temperature and shorter heating time. In any case, one important detail to keep in mind is to add enough water to support the length of time in the oven so that there is continuous formation of steam. Adding too little may result in the water evaporating too quickly without really getting the benefits of wet heat (as mentioned above, dry heat is not as effective and takes a much longer heat cycle to obtain the same sanitizing effects). Also, note that if your bottles are extremely dirty they may require a second pass through the oven. Some bottles are not even worth the effort.

Parts & Tools
Aluminum sheet metal (16 – 14 gauge)
Hand drill
1/8-inch drill bit
1.5-inch hole saw
(4) #6 screws and nuts
Pair of vice grips
Black Sharpie marker

1. Lay out bottle pattern and drill bottle neck holes 

Cut one piece of sheet metal 12-inch x 24-inch (30×61 cm) and another piece of sheet metal 12-inch by 32-inch (30×81 cm). Most metal supply stores will cut sheet metal pieces to your desired dimensions for a small fee. This is the easier way to go, but you may also use a regular hand saw. Using a black Sharpie, lay out the bottle pattern on the 12×24-inch (30×61 cm) piece of aluminum sheet metal. This bottle pattern is the same as they come in a 24-bottle case. Each bottle occupies a 2.5-inch (6.3 cm) square in an area of 10×15 inches (25×38 cm) centered on the 12×24 inch (30×61 cm) aluminum sheet. Using a hand drill with a 1.5-inch hole saw, drill the holes that are going to receive the bottlenecks on the 12×24 inch (30×61 cm) sheet.

2. Bend sheet metal pieces

Mark your bending lines and bend at 90 degrees. The 12×24 inch (30×61 cm) sheet is going to be bent 3.5 inches (8.9 cm) from each side. The 12×32 (30×81 cm) inch sheet is bent 7.5 inches (19 cm) from the sides. The easiest way of doing this is using a sheet metal bending brake. If you don’t own one, most shops have one and will charge next to nothing for this simple job (it takes less than 5 minutes to do these bends). As a last resource (as shown here), you could do the bends by clamping the sheet metal on a metal table with a clean edge and gently tapping the sheet metal with a rubber mallet.

3. Drill pin holes and assemble bottle rack

Use a hand drill with a 1/8-inch bit to drill pivoting/locking holes on corners of sheet metal parts. The location of these holes is going to determine the height of the bottles that will fit in the bottle rack. For the standard 12 ounce bottle, there should be a 7-inch gap between the bottom and top sheet metal layers. It would be useful to drill several of these holes approximately ¼ inch apart so that the rack can accommodate bottles of different heights. Lay sheet metal pieces on top of each other and secure by running #6 screws and nuts.

4. Insert bottles upside down

Insert bottles upside down in drying position and swing the cover over the bottom of the bottles and secure with pins. The bottles have to be compressed tightly between the layers of sheet metal so that no bottles come loose out of the rack in the next step. For this reason, it is very important that all bottles be the same height.

5. Fill each bottle with 1/2-inch of water

Flip the whole rack with bottles to upright position and add approximately ½ inch of water into each bottle with a hose, moving from one bottle to another in a continuous fashion to save time. The amount of water going into each bottle does not have to be precisely measured as long as you are in the ball park. Not too low that the boiling will stop too quickly or too high that it will take much longer for a given bottle to start boiling. While doing this, begin preheating the oven at 250 °F (121 °C).

6. “Cook” the bottles in the oven

Put the bottle rack in the kitchen oven that is now warmed up to 250 °F (121 °C) for 60 minutes. This will steam clean and sanitize the bottles. Let the bottles cool down after the heating cycle has finished, then take bottle rack out from the oven and flip to drying position. The bottles are now ready for use.