My recipe calls for a pound of DME at the beginning of the boil and 6 pounds at 15 minutes to go. What's the point of that?

  • Get your hands on the Oct 2003 issue of BYO. Read about the Texas Two-Step. Commented Feb 23, 2010 at 20:38

2 Answers 2


Hop utilization - the amount of acid bitterness extracted from hops - is greatly affected by the gravity of the boil, or the concentration of sugars in the boiling wort. The more concentrated the sugars, the less the hops will be utilized. If you are trying to attain a certain level of HBUs in your recipe, you can do one of two things - go with a more diluted boil or use more hops. Hops are expensive, so diluting the boil is a good choice. Once you've decided to dilute the boil, there are two ways to do this - you could go for a full 5 gallon boil or you could do a partial boil, say 2.5 gallons, with less extract in for the majority of the boil time. Given that most extract brewers, myself included, are not set up to do a full 5 gallon boil, adding your LME late is a good way to get the desired level of HBUs without using loads more hops.

  • This makes sense, too. Commented Feb 23, 2010 at 18:01
  • Take your favorite recipe and plug it into Beer Calculus. Set it to a 5 gallon average boil. Look at the HBUs. Now change nothing but the boil size. Change it to 2.5 gallons. The HBUs will drop dramatically.
    – JackSmith
    Commented Feb 23, 2010 at 18:05
  • Yeah, I've read that extract brewing requires 15-25% more hops for the same IBUs. Commented Feb 24, 2010 at 21:44
  • 2
    Ugh, I wish Beer Calculus had a checkbox for each fermentable to denote it as a late addition and exclude it from the boil. Commented Mar 24, 2010 at 17:42

When you brew light-colored beers using extract, you risk what's sometimes called kettle caramelization. Caramelization is actually a misnomer, as the lowest caramelization point for any of the sugars in wort would be above the boiling point of water.

The culprit is the Maillard reaction, which, in cooking, is responsible for a huge amount of deliciousness, but in brewing, provides a not-very-pleasing brown color.

If your recipe calls for a late addition, here's some tips:

  • Add the extract off heat
  • Make sure it's fully mixed with the wort before reapplying heat
  • Bring it back to the boil
  • Count the time that it was off heat and returning to boil toward the total time

You can't add all your extract as a late addition because the sugars in malt extract are beneficial to the isomerization of the alpha acids in the bittering hops (possibly by bringing the pH of the wort down?).

  • I think if we could combine jacksmiths answer and this answer you'd have THE answer. Late extract additions favors both wort color and hop utilization.
    – brewchez
    Commented Feb 24, 2010 at 12:49
  • Yup, I voted up his answer, giving him the lead. Commented Feb 24, 2010 at 21:44

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