I have 2 10 litre cookpots; one of which I've been using for brewing. I've been working with an 8 litre boil and a 12.5 litre batch size. I want to purchase a 23 litre extract kit. The kit includes 2 x 1.5 litre liquid malt extract cans, along with steeping grains and hops. If I do an 8 litre boil I know I will have darkening of the work and lower hop utilisation. I don't really care too much about the colour at this point, but would the hop utilisation be seriously affected, or would it be fairly minimal, and would this affect more the bitterness, or the flavour. Also would those be the only problems or might there be other issues.

I also considered doing two boils side by side but I only have one sink to chill the work ( using ice around the pot ) .... so I wonder if I put one boil on 20 mins after the other and did it that way would that be better than doing a single 8 litre boil.

I know there's a method of topping up 12-18 hours later but this would not work for me.

Kit - maybe something like this: HBC Full Extract American Pale Ale (23 Litres).

  • You might find that homebrew.stackexchange.com/questions/15112/… has some information related to this question.
    – Dale
    Nov 8, 2016 at 22:27
  • 1
    Thanks @Dale yes I had read that but he's talking about a pre-hopped kit I think and also his pot is just over half the size of mine that's why I was asking a separate quesion Nov 9, 2016 at 1:28

2 Answers 2


I would recommend NOT boiling the malt extract. There is absolutely no point in doing so. The extract is already sterile and at best only needs pasteurisation which can be done by dissolving the extract in several litres of near boiling water in the fermentation vessel when making up the wort. The flavour comes in the main from the steeped grain and hops and the un-fermented malto-dextrins of the malt extract.There is not much point in boiling roast grains either. Just put the grains in a suitable sized pan (or pans) and add boiling water. Allow to stand as preferred but 30 minutes is usually enough. Then strain into the fermentation vessel/bucket. Rinse grains with more hot water.

Many kits come with pre-hopped extract but some come with leaf/pellet hops and the hops usually need boiling. This is simple enough and can be done in a suitable sized pan (8 litres is good) by boiling with water for the required amount of time (eg 1 hour). Any timed hop additions are done in the usual way - just add hops to the boiling water at the required time. At the end of the boil time, strain the "hop tea" into the fermentation vessel and perhaps wash the hops with more boiling water. This is a good time to add the malt extract. When all (inc any sugars/syrops) is stirred in and dissolved, add cold water (and maybe some more boiling water) to reach the required volume and temperature in the fermentation vessel. When all ready and at correct temp - pitch the yeast. I recommend making an active yeast starter solution up with sugar in a suitable bottle some hours before brewing. If the yeast is bubbling then it can be added. If not get some more yeast!

I and others now use this extract method all the time and it produces great beer with less effort, less energy, and more safety. The cooling is done efficiently and rapidly using water (eg from a tap or in a bulk mineral water bottle) Boiling malt can be a dangerous thing, is at best difficult to clean up, is at worse a real scalding danger and for all of that does nothing for the final taste of the beer. Have a go - you won't go back to boiling it.

  • I agree that dissolving the majority of the extract after the boil is a good idea. I'd remove the hop bag before dissolving too, otherwise you soak up (and throw away) too much of your (concentrated) sugars.
    – Dale
    Nov 8, 2016 at 22:23
  • There's some talk about the hop isomerisation needing wort to be present - what do you think on that front Nov 9, 2016 at 1:29
  • Hop oils (eg humulone, etc) will isomerise perfectly well in boiling water. In fact alpha acid isomerisation is more complete in pure water than it is in wort(malt/water mixes). Humulone will even isomerise in a microwave. Nov 9, 2016 at 8:53

Most of the extract recipes I've brewed have been 'half-boil' recipes where approximately a third of the LME is added to the steeping liquid plus a few (4-5) extra litres of water for the boil. Boil then proceeds according to recipe, but less volume. The rest of the extract is then added when increasing volume and dropping temp ready for pitching.

Overall, have never had a problem with lack of hops flavour doing it this way.

I'm not sure about splitting a full boil into 2 parts, never tried it!

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