Cleaning and sanitizing equipment is the most important aspect of home brewing. Equipment that is not thoroughly cleaned can infect entire batches of beer, completely wasting them. While wort chillers do make the brewing process much easier and faster, they can be difficult to clean out satisfactorily.
Cleaning Immersion Wort Chillers
Immersion wort chillers are the easiest chillers to clean. The wort only touches the outside, visible part of the copper tubing that composes the chiller, so it is simple to tell if the surface has been cleaned well.
The best way to sanitize an immersion chiller after is to:
1. Immerse the wort chiller in a cleaning solution like Powdered Brewery Wash
2. Rinse the immersion chiller with water
3. Immerse the wort chiller in a sanitizing solution like Star San for a few minutes. This will remove anything remaining from the wort that could cause bacteria to grow.
This should be done before and immediately after every use. One should not clean off the copper by scrubbing it with anything like steel wool, even if it is suggested in some resources. Steel wool can scratch the tubing, allowing bacteria to get stuck in the scratch and infect batches of beer. Steel wool can also leave behind small fragments, which you do not want to find in your beer.
Oxidation of Copper Immersion Wort Chillers
You may notice that your copper immersion wort chiller looks shiny immediately after cooling wort, but when you go to cool another batch of wort a few days later it looks pretty dull. This is due to natural oxidation of the copper when it is exposed to air. It isn’t going to hurt your beer, but you may want to clean it off anyway. The wort chiller can be returned to its original brilliant state by soaking it in a sanitizing solution for a few minutes. It has been shown that you may even use a water/vinegar solution to do so. If you own a stainless steel immersion wort chiller you will not have to worry about oxidation.
Cleaning Counterflow Wort Chillers
Cleaning and sanitizing a counterflow wort chiller is trickier than sanitizing an immersion wort chiller since you can not see the surface that the wort actually touches to ensure there is no residue. The sanitizing process should be completed both before and after chilling wort to make certain that no bacteria is present in the tubing to infect beer. Both the inner and outer tubing of the chiller need to be sanitized.
1. As soon as possible after use, before anything has a chance to dry inside the chiller, the counterflow chiller should be flushed with a cleaning solution like Powdered Brewery Wash. The best practice is to run the cleaning solution through the chiller in the opposite direction than the wort flowed through so that it can dislodge any residue that may have been deposited in the chiller.
2. Rinse out the chiller with a good flush of clean water.
3. Flush the counterflow wort chiller with a sanitizing solution. An acid solution like Star San is going to do the best job of neutralizing anything that could grow bacteria in the chiller. Some resources recommend that you even let the solution sit in the chiller for a while to fully neutralize anything that could grow.
4. If both the inner and outer tubing of your counterflow wort chiller are copper or stainless steel the chiller can be baked in the oven to kill any existing bacteria. If the outer tubing is not a metal this step should obviously be skipped.
Cleaning Plate Wort Chillers
Plate wort chillers are the most difficult to properly clean of any type of wort chiller. Their design, while efficient, makes them susceptible to clogging with debris, and plate chillers usually can not be opened for cleaning.
Plate wort chillers should be cleaned immediately after use, before any wort has a chance to dry inside.
1. Start by back-flushing the plate chiller with a cleaning solution like Powdered Brewery Wash (PBW). The PBW solution should be pumped in through the “Wort-Out” connection so that it dislodges anything that was caught in the chiller during the cooling. This can be done by gravity or with a pump, but best results are reached using an Auto-Siphon to apply more force to the flushing.
2. Flush the plate wort chiller with PBW in the other direction by repeating step 1 into the “Wort-In” connection.
3. Flush the plate wort chiller in both directions using boiling water.
4. Flush the plate wort chiller in both directions using a sanitizing solution like Star San.
This process will clean out a plate wort chiller pretty effectively. There are further steps you can take, though, to really be sure that the chiller is cleaned out:
1. Submerge the plate wort chiller in a kettle of water or a PBW solution and boil for a while. This will loosen and release some of the residue in the chiller.
2. Bake the plate wort chiller in an oven for an extended period of time to kill any bacteria that may be inside.