Wednesday 19 October 2022

How to do a Whirlpool/Hop Stand in a BrewZilla

Many of today's hop forward recipes call for what is commonly known as a "whirlpool" or "hop stand" hop addition. The idea behind these additions is that they are done after the wort is slightly cooled from boiling temperature at the end of the recipe's recommended boil period. By adding hops at a lower than boiling temperature, more of the fruity and floral properties of hops can be extracted without as much bitterness being imparted into the wort.

Whirlpool additions are typically added at around the 75°C - 85°C and are left to 'steep' in the wort for a period of 10-20 minutes. During this period, the wort is circulated, either manually or using a pump to aid in hop utilisation which causes a whirlpool like effect (hence the name). Your recipe should stipulate at what temperature and for how long the whirlpool hops should be added.

An example whirlpool in a BrewZilla (using water)

Homebrewing applications like Brewfather have a dedicated feature for whirlpool hop additions to help calculate how much bitterness (measured in International Bittering Units (IBUs) will be imparted from the whirlpool hop addition - based on the whirlpool temperature, duration and the Alpha Acid properties and quantity of hops being added.

If you're using a BrewZilla, you may be wondering how you go about performing a whirlpool. The process is really straightforward, but there are a couple of neat tricks to help make it easier and more efficient which we'll outline below.

BrewZilla Whirlpool Arm Attachment

Before we begin, it's worth mentioning that a whirlpool arm attachment for your BrewZilla is a worthwhile addition (but not mandatory) for performing a whirlpool. The whirlpool arm attachment connects to the pump outlet of your BrewZilla in place of the recirculation arm that is typically used during the mash. You don't have to use a whirlpool arm, but if you don't you will need to manually stir your wort during the whirlpool using a large spoon or mash paddle etc.

We also recommend a separate thermometer, preferably with a long probe that you can insert into the top of your boiling wort to measure the temperature of the wort from the top. The built-in temperature probe for the BrewZilla is located at the bottom of the unit, right near the heating elements so is not a reliable gauge for the actual temperature of the wort itself.

Our long probe thermometer for measuring whirlpool temperature

Here's a step by step guide on how to perform a whirlpool/hop-stand with your BrewZilla;

  1. Perform your mash, boil and hop additions as per your recipe. Typical boil times are 30 or 60 minutes.

  2. 5 minutes before the end of your recipes boil time (eg. after 25 minutes have elapsed for a 30 minute boil or 55 minutes have elapsed for a 60 minute boil), disconnect your re-circulation arm attachment and fit the whirlpool arm attachment (if you're using one). We add it whilst the wort is still boiling to allow the boiling wort to sanitize it.
    We also like to ensure that the whirlpool arm outlet faces the opposite direction to how the water will be flowing through the immersion chiller to maximise cooling efficiency.

  3. Also put your immersion chiller into the BrewZilla - and if you're using a paddle/spoon to stir and create a whirlpool manually, dip it into the boiling wort as well for sanitizing.

    BrewZilla with whirlpool arm and immersion chiller

  4. Connect the hose attachments to the chiller (but don't begin flowing water through it yet.)

  5. This is where things get busy. At the end of your boil, turn on the flow of water through the immersion chiller.

  6. If you're using the whirlpool arm attachment, turn on the pump on the BrewZilla and ensure the ball lock valve adjustment is fully open to allow maximum flow of wort through the whirlpool arm attachment. If you're not using a whirlpool arm attachment, start stirring to create a whirlpool effect.

  7. Adjust the temperature of the BrewZilla from "HH" (maximum/boiling) to around 5-7°C above the recommended whirlpool temperature. eg. If your whirlpool temperature is 80°C, set the BrewZilla target temperature to 85-87°C. Ensure both heating elements are On.

  8. Monitor the temperature of your wort using the thermometer probe inserted from the top of the BrewZilla into the wort.

  9. Once the temperature of your wort (according to the separate thermometer you're using) has reached around 5-7°C above your desired whirlpool temperature - stop the flow of water through the immersion chiller. You can turn it off at the tap, or simply kink the hose. You'll notice that even after stopping water flowing through the chiller, the temperature will continue to drop a few more degrees which is why we stop the water flow before reaching our target whirlpool temperature.
    Note that the time for the temperature to drop from boiling to around 85°C is quick - usually around a minute - but there are lots of variables that can influence this like the water flow rate and chilling water temperature.
    Don't take the chiller out of your wort either, leave it in place.

  10. Add your whirlpool hops - we use a hop spider but this is a personal preference - otherwise just throw them straight into the wort. If you're using a hop spider, we like to move/jiggle it around a little to help aid utilisation during the whirlpool period.

  11. Start the timer for your whirlpool hop addition.

  12. Leave the pump running through the whirlpool arm attachment for the duration of the whirlpool/hop stand. Once the time has elapsed, continue flowing water through the immersion chiller and turn off the heating elements. Also remove the insulating jacket if you're using one to help aid with cooling.

  13. Continue to chill your wort then transfer to fermenter as per normal by refitting the recirculation arm attachment.






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