brewing innovation  


New to the Blichmann Engineering lineup is the patented HopBlocker™ boil kettle filtration system! Over a year of brutal, but tasty field testing, our dedicated R&D team yielded a filtration system that has up to 95% efficiency on pellet hops and is virtually impervious to plugging! We have tested the HopBlocker™ with more than a pound of pellet hops in a 20 gallon batch, and it brought them to their knees.


Traditional screen filters draw from the bottom of the kettle — immediately sucking all pellet hops and fine break material into the screen, where they plug. In Blichmann Engineering's HopBlocker™, preferential flow leaves settled fine break material (hops and trub) undisturbed at the bottom of the kettle while draining the majority of the wort through a coarse filter from the top down. When the wort level is just a couple of inches from the bottom of the kettle, the fine filter element is then exposed by lifting the shield, and the remainder of the wort is filtered. It's an intuitive design that allows the fine filter to work only on a small portion of the wort, not all of it. The HopBlocker™ will filter up to 95% of the break material and hops from your wort without plugging. While it is designed specifically to complement Blichmann Engineering's BoilerMaker™ brew kettles, the HopBlocker™can be installed in any manufacturer's kettle or keg.

NOTE: The HopBlocker is designed for use with pellet hops only. Whole/loose hops will plug the unit. While using whole hops, or a mix of whole and pellet hops, you must bag your whole hops in a large muslin grain bag. This will not affect the utilization rate and will result in significantly less wort loss.


1. Install the HopBlocker™ into the kettle using the snap-in dip tube. This takes only a few seconds.

2. Ensure that the shield is pushed all the way to the bottom of the screen and that the HopBlocker™ is resting flat on the bottom of the kettle. Proceed with your boil as you normally do. The HopBlocker™ may move a bit during the boil, but this is not a problem. It will automatically right itself.

3. At flameout, vigorously stir the wort with a paddle to create a whirlpool. This encourages the hops and trub particulates to settle to the center of the kettle, away from the HopBlocker™. 

4. Allow 15 to 20 minutes for thermal convection currents to slow and allow the break material and hop particulates to settle.

5. Drain your pot as fast as you'd like until you see the top of the kettle drain fitting (about 3 inches of wort).

6. Reduce the drain flow rate to about one-third of the initial flow rate. This allows the wort to slowly permeate through the hops and trub without dragging them to the filter where it may plug.

7. Use your paddle to hold the filter down and quickly pull the shield up with a gloved finger or a racking cane to expose the fine filter on the bottom of the HopBlocker™. It is important to quickly complete steps 6 and 7 so you do not lose the siphon, which will stop the flow.


Loose leaf hops generally plug the coarse screen. Therefore, we highly recommend using large muslin grain bags to avoid plugging.  In addition, you lose a large amount of wort from leaf-hops absorption. Using a bag, you can squeeze most of the wort out with negligible effect on hop utilization and significantly easier cleanup. This method does not work for pellet hops because they pass through openings in the muslin bag. And finer mesh screens do not freely allow wort to pass so hop utilization is negatively affected.


The HopBlocker™ was specifically designed for use in Blichmann Engineering BoilerMaker™ brew kettles. However, it can be installed in other manufacturers' equipment. A 1/2" outside diameter drain tube with a 90-degree bend (not included) must be installed, with the bottom of the tube between 3/8" to 1/2" from the bottom of the kettle or keg. Because you can't rotate the tube to thread it into the inside of your pot when the tube is inserted into the HopBlocker™, you will need a flare or compression connection so you can tighten the tube in place without turning the tube. Try to locate the tube so that the HopBlocker™ is as close as possible to the sidewall of the pot. For kegs, you will need to install the HopBlocker™ in the center of the kettle due to the rounded bottom, reducing the HopBlocker's™ effectiveness.


Manual / Video

Click the link below to download a PDF of the current HopBlocker™ product manual.



Just wanted to let you know that your new hop filter is incredible! I previously used your T-shaped boil screen then switched to a homemade version using steel braid, but your new-style filter was a tremendous improvement over either. The wort drained much more quickly than before, and even though I left more hot break in the kettle, I still managed to get more wort out, reducing my water needs by approximately 1/2 gallon.

Thank you for another great product. I had been eagerly waiting for the new filter, but the unique design of this far exceeded my expectations. I will be recommending this to all of my brewing friends.

— Mike Zeman, Vancouver, Washington, Member of the Bader Brewing Club



Why does my HopBlocker™ plug when used with whole hops?

The HopBlocker™is designed for use with pellet hops only. Whole loose hops will plug the unit. For using with whole hops, or a mix of whole and pellet hops, you need to bag your whole hops in a large muslin grain bag. This will not effect the utilization rate and will result in significantly less wort loss. Note that using small, fine-mesh nylon hop bags will reduce your hop utilization significantly. But the loose open nature of disposable muslin grain bags allow the wort to flow freely in and out of the bag, and utilization is not affected.

Why does my HopBlocker™ plug even with pellet hops?

This is almost always from not waiting 15 to 20 minutes after whirlpooling to allow the convection currents (churning) to stop and the particulate matter to settle to the bottom of the pot. The other cause is not slowing the flow enough when you reach the level of the drain tube. It is vital that you use a slow drain rate to allow the wort to permeate through the hops/trub and not drag these particulates with it into the filter. Remember, this product does not work like a traditional filter. It directs the wort flow and allows the hop particulates to settle away from the drain tube and prevents them from getting suspended again and plugging the screen.