A couple of months ago I purchased three Ss Brewtech 1 Bbl Unitanks for my home brewery. I've had time to put a few batches through them and get accustomed to their specific cleaning needs. Like all tanks on the market, they have their own little peculiarities that require attention in order to properly clean them. They are remarkably similar to commercial tanks with the exception of not having a manway on the side of the tank. For inspection and reaching into the tank, the glycol chilling coil port on the top of the tank serves this purpose.
My method is somewhat similar to a procedure you would find in a commercial brewery but scaled down to a home brew scale. This is adapted from my experience cleaning fermentors in the craft brewing industry. I understand that this method may not be well-suited for certain indoor settings. I am performing these procedures in a garage-like environment and on epoxied floors with a built-in trench drain, enabling liberal spraying and plenty of messy work to be done.
Basically, I fill the tank with a reservoir of hot PBW solution and circulate it inside the tank using a spray ball mounted within. This is known as a CIP (Clean In Place) procedure. This requires a pump capable of spinning a spray ball such as a March pump or Chugger pump and a miniature spray ball that can be mounted inside of your Ss Brewtech unitank. There has been a recent appearance of such miniature spray balls on the market, including one offered here by Ss Brewtech. It is important to get a spray ball small enough to be spun by your pump otherwise it won't do much cleaning.
This step-by-step guide is accompanied by pictures I took while cleaning a fermentor after racking a partial batch of Imperial Stout from it.
Ss Brewtech Unitank Cleaning
Step 1: Dump remaining tank contents: I attach a drain hose to the bottom valve and crack it gradually to dump the remaining trub and yeast sludge from the bottom of the tank. Since I have normally just finished kegging and/or bottling from the tank, there is usually a head pressure of 10psi or more still on the tank. Don't throw your drain valve wide open, or you will likely blast sludge all over your brew space! As can be seen in the above image, I am dumping the tank into a trench drain in the floor. For those who lack such amenities, dumping the tank into a bucket or other container works as well. Be sure to vent the tank down to atmospheric pressure before proceeding to the next step. After pressure has bled down, leave the blowoff arm open and remove the pressure gauge on the top of the tank. Very gently scrub the underside of the pressure gauge with PBW or soap. The sanitary diaphragm is delicate so be careful with it!
Step 2: Break down tank side ports and racking port: The three side ports on the unitank and the racking port are all shadow points, which means they don't get flow through of cleaning solution, when trying to perform a CIP. I learned this the hard way the first time I tried cleaning after my first batch of beer in the unitank. I ran my cycles and then took everything apart to find yeasty sludge still sitting in the ports! So in order to effectively clean these ports, remove all fittings from them after draining the tank and spray them out with a hose. scrub any caked on material with a blue scrubbing pad and soap or PBW. Rinse off all parts removed from the ports and set them aside soaking in hot PBW solution.
Step 3: Pull out chilling coil and do some more spraying: Remove the glycol chilling coil from the tank and spray it off. There will be a good bit of caked on material where the liquid line was in the tank during fermentation. The same will be true around the inside of the fermentor. In the above picture, the Krausen ring was just above the top of the fermentor bottom cone because I only had a partial batch in the tank. normally the ring will be much higher up. Do some blasting with your garden hose to break up much of the ring and wash it out of the tank. At this point, it helps to reach in and scrub the ring with soap and a blue scrubbing pad. The same can be done on the chilling coil to remove the caked on organic matter. It is debatable whether any scrubbing is required. If the CIP cycle is performed with a sufficiently strong cleaning solution at a high enough temperature, all of that organic matter should be broken down. I have run my CIP cycle on very dirty tanks and had squeaky clean results. However, the less matter there is during the CIP cycle, the less likely you will need to run the cycle again. Better safe than sorry many would say!
Step 4: Install CIP spray ball and run rinses. The spray ball will be mounted in the place of the PRV. I like to add a 90 degree elbow to the assembly as seen in the above image to better orient the connected hose and prevent kinking. Reinstall the glycol chilling coil into the top of the tank. Perform 3x30-second burst rinses through the spray ball using a garden hose. To do a burst rinse, turn on the hose for 30-seconds and then turn it off again. Wait for the rinse water to finish draining before repeating the procedure. This is just for good measure to rinse out anything else that can be eliminated before the cleaning cycles begin. As can be seen in the above image, I have a garden hose thread x 1.5"TC adapter that enables me to connect my garden hose directly to the spray ball. these can be found at Brewers hardware for $16.00.
Step 5: Cap off ports and fill tank with cleaning solution: Cap off the three side ports and the racking port on the tank using 1.5" end caps. Then fill the tank with approximately 12 gallons of 180 degree hot water. The reason I use 12 gallons is because that fills the tank to the top of the cone, which will give you immersion of all three side ports and the racking port during the cycle. I use PBW as my alkaline cleaner during CIP cycles at a rate of 1oz/gal or higher for dirtier jobs. you can either add the PBW while heating your water, or add it directly into the fermentor after transferring the water. Be sure you have removed the pressure gauge from the top of the tank at this point! It is important that the tank not be sealed during the CIP cycles so as to avoid a vacuum occurring. This is imperative because a vacuum could implode your tank! PBW reacts with CO2, which is an acid. If there is enough CO2 still remaining inside your fermentor and it is sealed, a vacuum could very easily result and your lovely tank could crumple. removing the Pressure gauge and leaving it off during the cleaning cycle is my way of preventing this. I transfer the PBW solution with my pump into the fermentor from my hot liquor tank through the drain port on the fermentor.
Step 6: Run a 5 minute blowoff loop: The first CIP cycle I run is through the blowoff arm for 5 minutes. Set up your pump to pull from the drain port on your fermentor and run solution through the blowoff arm (see above image). This makes a loop using the PBW in the tank as your cleaning solution reservoir. Make sure your pump is primed and run the loop for 5 minutes.
Step 7: Run a 20-30 minute CIP cycle through the spray ball: After the blowoff loop has been run, disconnect from the blowoff arm and connect your pump outlet hose to the spray ball connected to the tank. Run this loop for 20-30 minutes.
Step 8: Drain fermentor and remove port caps: Once your main CIP cycle is complete, disconnect your pump and drain the PBW solution from the tank. Then remove the port caps and blast them with your garden hose again.
Step 9: Perform final rinses: Attach the garden hose to the blowoff arm and flush the residual PBW out with 3x30-second rinses. Attach garden hose to spray ball again and perform 3x30-second burst rinses. Then remove the chilling coil from the top of the tank and do some final spraying with the garden hose through the top. Visually inspect the interior of the tank for any remaining soil. The interior of the tank should be completely clean. If so, all that remains is to rinse off the tank parts you left soaking in hot PBW.
Sanitizing: After cleaning, the tank only needs to be sanitized before being refilled with wort. Sanitizer cycles are most commonly performed with Star San or Saniclean in a home brewing setting and the procedure can be done the same way as a PBW cycle. I would use less liquid, only 5 gallons instead of the 12 gallons used for the cleaning cycle. The side ports should be clean and it is not necessary to keep them submerged during the sanitizing cycle. Before running the cycle, soak your just cleaned port fittings in sanitizer and rebuild the tank. it is handy to keep a spray bottle with Star San to spray the ports before attaching the fittings. then run the cycles like before (blowoff, then spray ball). reduce your cycle times to 2 minutes for the blowoff, and 5-10 minutes for the spray ball. then drain the sanitizer from the tank and replace the spray ball with a sanitized PRV fitting. Also don't forget to sanitize the pressure gauge and reinstall it on the top of the tank.
Depending on how long your fermentor sits between brews, it may be necessary to run another cleaning and sanitizing cycle prior to brewing.