Boil Kettle


STEP 1: Install the Hop Stopper filter screen

After the wort has been boiled it needs to be removed from the kettle leaving behind as much of the solids as possible, such as hops and hot break material (the protein clumps that coagulate in the first few minutes of boil). A filter of some sort if required to do this. The product we use is called the Hop Stopper. It's a large stainless steel mesh screen that covers a dip tube that extends down to the bottom of the kettle. The bottom of the dip tube is notched such that wort flows into it from all sides. We use an all stainless steel version instead of one with copper/brass parts as stainless steel is easier to clean, stronger, and holds up better over the years to contact with acidic liquids such as beer.

Blichmann Engineering (the manufacturer of our BoilerMaker kettles) used to sell a boil filter screen for their kettles but brewers noted that it would often clog regardless of the amount of hops used. Today, their boil filter screen is no longer sold. Instead, Blichmann now offers a product called the HopBlocker that looks promising but seems it may have a few caveats for use in our setup: Before draining, the HopBlocker requires the brewer to whirlpool (quickly stir to form a funnel) at the end of the boil and then wait 15-20 minutes to ensure that as much hop and hot break material as possible settles in a cone at the bottom center of the kettle. This may work well with kettles that are heated by propane or natural gas burners from below, but it's likely that our electric heating element would impede the whirlpooling effect and possibly render the HopBlocker ineffective in our setup. Our Hop Stopper works remarkably well with no effort or waiting required so we have not considered replacing it with the Blichmann HopBlocker.

The Hop Stopper is installed in our Boil Kettle (BK) prior to the heating element being installed. The Original Blichmann boil filter is shown (not installed) for reference only to show the large size of the Hop Stopper. The Hop Stopper uses a finer mesh screen and is considerably larger in surface area:

Close-up of the original Blichmann boil filter with diverter cover removed next to the Hop Stopper:


Installation of the Hop Stopper is very simple:  

  1. Remove the dip tube that was supplied with your BoilerMaker kettle (it simply pulls out of the drain fitting, no tools required).
  2. Remove the shaft collar from the dip tube by loosening the set screw with a 9/64" hex key.
  3. Slide the shaft collar onto the Hop Stopper dip tube. Do not tighten the set screw.
  4. Install the Hop Stopper in the kettle by sliding it into the drain fitting approximately 1".
  5. Slide the shaft collar onto the drain fitting until the pin engages the small hole in the drain fitting.
  6. Tighten the set screw with a 9/64" hex key.

The exact position of the shaft collar on the Hop Stopper dip tube is not critical: The Hop Stopper dip tube must insert far enough into the drain fitting to seal with the silicone o-ring, but not so far as to prevent the the ball valve from opening and closing.

The Hop Stopper uses the same silicone washer seal as the original dip tube. Removing it to clean is as simple as pulling it out. No tools are needed.

Dip tube removed from the kettle. The shaft collar is still attached:

Dip tube with shaft collar removed using a 9/64" hex key:

Hop Stopper with the shaft collar attached, installed in the Brew Kettle:


The Hop Stopper works extremely well at filtering out any amount of hops we've thrown at it.  A typical lightly hopped 10 gallon batch of beer will generally use about 2 to 4 ounces of hops during the boil. A more heavily hopped style may use 6 to 8 ounces. Extremely hoppy beers, such as Imperial India Pale Ales, may use up to 22 to 26 ounces. Our Hop Stopper has never had issues with any of these.

Below are some photos of the Hop Stopper after it successfully filtered out 23 ounces of hops from one of our Imperial IPAs.

The Hop Stopper after successfully filtering 23 ounces of hops from an Imperial IPA.
The hop material is over 2" thick in spots but the kettle still drained without issues.