Adding lme and dme at diff times? Does it matter?

[kryznic]

So I was reading "How to brew" by John Palmer and I came across some directions for a APA and he mentions disolving the DME in cold water first then at the end before flame out just dissolving the LME to pasteurize it?

I have only dissolved the DME into warm or boiling water at the same time with the LME. Would I net a better malt flavor by doing it his way? Does it really matter that I throw it all in the beginning?

 

[BigB]

This is a quote from Bunnchiro Brewing... I think it explains it well

"The Late Extract Addition method serves three purposes. Primarily it prevents the wort from darkening through caramelization of the sugars, during a full or extended boil. This helps to keep your lighter colored beers in the intended style range. Secondly it allows for more control over the flavor of the beer, especially when you want to present either the hop or yeast flavors over the malt. Finally it allows for better hop utilization as the enzymes in the wort are present to aid alpha acid extraction from the hops but the gravity of the wort is lower so utilization is improved. Make sure to adjust your hops accordingly if you do not want the extra bitterness in your beer.

Aside from withholding the majority of the extract until the end of the brewing process, the most effective way to prevent caramelization is to completely remove the kettle from heat when adding you extract. The make sure it is completely dissolved before bringing back to a boil."

 

[JLem]

I wait until the final 15 minutes or so to add my extract. Like BigB's quote above, this helps with hops utilization (EDIT: REMOVED INCORRECT INFORMATION).

If you are doing all extract, add some (halfish) at the beginning and then the rest late. Doesn't matter if it's DME or LME.

Also, FWIW, my understanding is that late extract addition has little effect on color. Caramelization occurs at temps above boiling. You only have to worry if you scorch undissolved extract on the bottom.

 

[SumnerH]

I wait until the final 15 minutes or so to add my extract. Like BigB's quote above, this helps with hops utilization (hops don't isomerize as well in highly concentrated wort

This is not true. Isomerization is independent of wort gravity, as is overall hop contribution to IBUs--hops utilization is independent of wort gravity.

Now, there are some correlated effects that serve to confound this--already isomerized alpha acids adsorb to proteins, and (especially in all grain boils) higher gravity worts tend to have more proteins than lower gravity worts. But that's not a strict correlation; a 1.050 OG all-grain wheat beer will almost certainly have worse hop utilization than a 1.060 OG extract barley APA.

As a good demonstration of the OP's question, Basic Brewing Radio brewed the same recipe (with the same hop schedule) as a full boil, partial boil, and partial boil with late extract additions, then measured the IBUs of the 3 beers. Hop utilization was essentially identical. March 4, 2010 - BYO-BBR Experiment III:
http://www.basicbrewing.com/index.php?page=radio

John Palmer's discussed the science in his "What is an IBU, Really?" podcast from 20 March 2008 where he talks about it (including apologizing for getting this wrong in the most recent edition of How to Brew):
http://www.basicbrewing.com/index.php?page=basic-brewing-radio-2008

More discussion here:
https://www.homebrewtalk.com/f128/estimating-bitterness-algorithms-state-art-109681/
https://www.homebrewtalk.com/f14/hop-utilization-178668/

 

[JLem]

This is not true. Isomerization is independent of wort gravity, as is overall hop contribution to IBUs--hops utilization is independent of wort gravity.

Didn't know that (obviously). Thanks for the info and the links.

So, are the hops utilization curves/tables out there inaccurate and/or outdated? (for example, the hops utilization table at the bottom of Glenn Tinseth's page - http://www.realbeer.com/hops/research.html)

 

[SumnerH]

Didn't know that (obviously). Thanks for the info and the links.

So, are the hops utilization curves/tables out there inaccurate and/or outdated? (for example, the hops utilization table at the bottom of Glenn Tinseth's page - http://www.realbeer.com/hops/research.html)

Yes, as is most brewing software. Note, however, that there are other factors involved (e.g. the amount of break material for isoalphas to adsorb to) that make those tables close to accurate for all-grain brewing.

What exactly the situation is for extract brewing is a lot muddier; to me, the difference in hop flavor between regular and late-addition extract brews was pretty small (much smaller than the software and tables would guess). BBR's test above showed that at least for that beer, the IBUs were close to identical between the two methods--which doesn't necessarily mean that flavor is the same, but is one objective measurement.

However, there are a lot of people out there with a lot of experience who think otherwise. With the majority of information about hops utilization vs. wort gravity only really coming out in the homebrewing community in the last 18 months, it's still an area of ongoing research.