I am in the process of adding a ball valve to my brew kettle and am designing a diptube to transfer wort to my primary. I've always brewed in 5-gallon batches so picking up the kettle and dumping it has never been a problem, but I would like to automate this process as much as possible and am wondering if I can just rely on gravity to drain the kettle as long as the kettle is higher than the primary vessel or whether I will need a pump to automate the entire process. I understand that this pump is not self-priming so I would to siphon enough to fill the pump to get it started, but that it would be able to drain the kettle much quicker once started. Speed is not that big of an issue at this point, but being able to drain all of the wort is a priority.

So, can I rely on gravity to drain the kettle after the ball valve is opened or must I use gravity and a pump?

3 Answers 3


If the only purpose for the pump is draining the boil kettle, it might be wise to avoid the complexity (and one more thing to clean), because gravity will certainly work to transfer your wort to the fermentation vessel.

You may find that there is an incomplete transfer of wort. The volume depends on how far the ball valve is from the bottom of the kettle (even if the pick-up is lower). What I do is put a length of silicone tube on the output of the boil kettle and submerse that in the fermenter. This way, it siphons more wort, because without the tube, it breaks the siphon.

Use gravity and reduce cost, complexity, and cleaning!

  • There is an important point here. Attach a length of tubing to the valve; otherwise, your dip tube won't work. Oct 17, 2011 at 0:38
  • Exactly right. I tested the diptube assembly I soldered this weekend and it worked perfectly using good old gravity. I doubt the specific design of the diptube matters much, but I did use a 3' length of tubing and as soon as I opened the valve, the siponing started and completely drained the kettle (well, within a few ounces). I consider this a success since I will no longer need to wrestle with the kettle to drain it.
    – Bill Craun
    Oct 17, 2011 at 1:16
  • 1
    Remember that you don't necessarily want to completely drain the kettle. Leaving the hot-break behind is generally considered a good idea.
    – baka
    Oct 17, 2011 at 2:11
  • Right. I designed mine with a 90 degree elbow under the valve about 1/8" above the surface of the kettle with that in mind.
    – Bill Craun
    Oct 19, 2011 at 23:29

It will work fine by gravity.

But the amount of wort you get out of the kettle is dependent upon the geometry of your pots bottom, and how your pick up tube is positioned in the pot.

  • 1
    Excellent correct answer! But if you buy a pump, you'll find other uses for it. I bought one to do recirculating cooling and found that it cut my cooling time to less than half of what it was before I used a pump. I consider the ability to xfer wort to the fermenter a wonderful, but secondary, benefit.
    – Denny Conn
    Oct 16, 2011 at 19:24
  • 1
    I am with Denny on the pump as well. I finally got my pump put "inline" with my mashing and chilling process as well. Certainly saves a good amount of time on the chill end. And I like just redirecting the return hose to the fermentor once the whirlpool is done.
    – brewchez
    Oct 17, 2011 at 11:58

I used a racking cane and gravity for 3 years worth of brewing, and it worked just fine. I don't see any reason you couldn't rely on gravity.

It will be slower than a pump, but you're looking at 3-5 minutes to fill the fermentor, rather than less than 1 with a pump, basically.

  • My kettle's valve and pick up tube works just fine by gravity. No pump needed.
    – brewchez
    Oct 16, 2011 at 18:40

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