The starting position for most new extract brewers is to use a partial boil set up. Defined as using a pot smaller than the intended batch size, all the ingredients are boiled in a smaller volume. Then the wort is diluted to the final desired batch size. (Often the dilution step is used as part of a cooling step)

What are the Ups and Downs of both Partial vs. Full boils?

  • This might be a good place to start, I asked something similar and got some good answers: homebrew.stackexchange.com/questions/971/… Commented Jan 9, 2010 at 16:27
  • I always wondered why my brews were always drarker, thanks for the post!
    – user2449
    Commented Jun 2, 2012 at 18:11

2 Answers 2


Boiling is a fairly poorly understood process. That being said here is what I know.

Partial-wort Boil


  • You probably already have all the necessary equipment
  • Small footprint
  • Easy to manage
  • You can use your kettle for other things


  • Hop utilization suffers, meaning you must use more hops to get the same level of bitterness
  • There is a limit to iso-alpha acid concentration in wort - might have trouble making your favorite imperial double IPA. citation needed
  • It is much more difficult to accommodate all-grain batches because they necessitate full-wort boils
  • Boil-overs make a mess on the stove
  • You should sanitize top-off water to minimize infection risk, giving you another process to mind
  • Wort-darkening reactions happen faster at higher concentration, so your beer comes out darker than expected

Full-wort Boil


  • You can handle a full batch of wort from a mash tun
  • Hop utilization is better
  • Wort-darkening reactions happen at an expected concentration
  • You can size your kettle to minimize the possibility of boil-over


  • It is very difficult to boil a full batch on the stove, making it necessary to buy a burner in addition to a large pot
  • Boil-overs make a mess on the deck/garage/sidewalk
  • More (large) equipment to manage & store
  • Very nice summary.
    – brewchez
    Commented Jan 10, 2010 at 16:35
  • Hop utilization is usually greater with partial boil, because it is combined with late addition extract.
    – Wyrmwood
    Commented Jun 5, 2017 at 21:11
  • If you are boiling a higher concentration of sugars, hop utilization will be lower (thought there is some question here...), but if you are adding extract late, which I would imagine most would be these days, then the utilization is actually higher.
    – Wyrmwood
    Commented Jun 5, 2017 at 21:18
  • 1
    One important point missing: Partial boils are easy to cool to pitching temperature without extra equipment. 3 Gallons can be cooled down easy enough by putting the stockpot in cold running water in the sink (may have to add ice if you have warm tap water), 5+ gallons requires a chiller of some kind.
    – Mumble
    Commented Jun 6, 2017 at 6:32

Do not boil the wort when making beer from extract. There is no reason to do so. One can do it but it will turn out the same as when not boiled. Many extract beer kits now recommend this method for safety and for economy/efficiency.

Hop utilisation IS NOT BETTER in a full wort boil. It is better when the hops are boiled in plain (tap) water and that water added to the extract/sugars in the Fermentation vessel.

"You can handle a full batch of wort from a mash tun" - really? With an extract brew why would one use a mash tun?

"Hop utilization suffers (in a partial boil)" - no it doesn't, that is just plain wrong. Hop utilisation is maximised when boiling in plain water.

  • "Hop utilization suffers (in a partial boil)" - no it doesn't, that is just plain wrong....... @barking.pete based on what I've read, it seems to be a widely accepted perspective that partial boils do, in fact, cause less hop utilization. I must be misinterpreting what you are saying because it sounds like you're contradicting yourself. If boiling hops in water and adding it later maximizes hop utilization (which I agree with btw), how could doing anything else not cause utilization to suffer? I'd be really interested to hear your elaboration.
    – thekolnik
    Commented Jun 5, 2017 at 20:28
  • The statement that hop utilization is maximized in water does not there in negate the statement that hop utilization goes down in a concentrated boil. In fact, it proves it in the first place. Less dilute wort increases utilization; where water would be the ultimate in less dilute wort.
    – brewchez
    Commented Jun 6, 2017 at 10:31
  • Boiling hops in less than the full volume of water does not cause hop utilisation to suffer compared with boiling in wort.But it is fair to say that no boil utilises the hops fully. From my own experience/experimentation, boiling in more water than 30% of the planned total wort volume does not seem to increase the hop flavour or bitterness of the beer. I have tried 50% and 75% as well as 95% (full) volume boils of water with the hops. Few if any who tasted the various beers (blind and informed) thought the increase over approximately 30% final volume improved the final flavour of the beer. Commented Jun 6, 2017 at 15:29
  • @barking.pete Thanks for sharing the results of your experimentation. It's hard to debate empirical data. I think I'm going to try that myself just for fun! I think what had me confused was your original phraseology. I think what you were saying was that boiling in 3 gal. of wort vs. 5 gal. of wort results in the same hop utilization. However, boiling in pure water is better than both of those.
    – thekolnik
    Commented Jun 6, 2017 at 16:39
  • yes - I intended to promote the idea that boiling hops in water results in greater hop utilisation than boiling hops in wort. I am sorry if I caused any confusion. Is it difficult to judge the experiments of others but as you say a simple test of 30% vs 90%(or even 100%) of final liquor volume for boiling the hops in should prove the point. IMHO dry hopping can be used to add more and subtler flavour than provided via the kettle hops. YMMV Commented Jun 7, 2017 at 17:01

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