adding half lme at boil other half at end of boil

[tankmech]

What does this achieve. I seen some other posts talking about this. Just wondering what this does to the beer?

 

[boydster]

It helps keep the extract from scorching, which keeps your color and flavor closer to where you intend and helps to prevent caramelizing fermentable sugars into unfermentable ones.

 

[ncbrewer]

Also, traditional thought is that lower boil gravity increases hop utilization. Recently, there's been considerable disagreement, even among experts. I personally think you get better utilization, but I do my initial boil at roughly 1.040 gravity and use the Tinseth formula to calculate bitterness. That should give me a good prediction of bitterness.

 

[TipsyDragon]

First you can't caramelize sugar in a boil. Caramelization requires high heat and low moisture. The browning you see is from Maillard reactions similar to what you see when you bake bread. Adding half the extract at the end of the boil is meant to lessen this. It is an optional step and meant for cosmetic reasons. You will have to adjust your hops additions to account for the different boil gravity.

 

[boydster]

First you can't caramelize sugar in a boil. Caramelization requires high heat and low moisture. The browning you see is from Maillard reactions similar to what you see when you bake bread. Adding half the extract at the end of the boil is meant to lessen this. It is an optional step and meant for cosmetic reasons. You will have to adjust your hops additions to account for the different boil gravity.

If the LME sinks straight to the bottom without mixing with the water it seems possible to scorch and caramelize (different than maillard reactions). That is what people are usually worried about when they talk about extract twang... Boil gravity may or may not effect hops utilization, a lot of experts are now saying it doesn't effect it. My brewing software still takes it into account, though.

 

[hellawaits77]

I personally use add ~25% at the start, and the rest at between 15-10 remaining. Has certainly helped keep the beer lighter in color.

 

[unionrdr]

Scortching is def a concern,moreso with LME as stated. I use 1.5-2lbs of plain DME in the boil for hop additions out of a 3lb bag when doing AE. I add the remaining DME & all LME at flame out to lessen scortching & maillard reactions. Def gives better flavor & lighter color. It's referred to as late extract addition. Here's the wiki on maillard reactions for those interested; http://en.wikipedia.org/wiki/Maillard_reaction