What is the purpose of splitting up LME in boil

[system]

Good morning!
While reading different articles, forum threads and recipes yesterday, I read someone’s comment that they split up the LME in the boil. (Sorry, I don’t remember where I read that.) They would pour in half of it as usual, but would save the other half for later in the boil. What is pro’s/con’s of that method?

Thanks,
Shad

[mainebrewer]

It is usually done when doing a partial boil. For example, making a 5 gal batch but only boiling 3 gal and then topping up with 2 gal of water.
By reducing the specific gravity of the boiled wort, the hop utilization is increased and the darkening of the wort is reduced.

[system]

@mainebrewer

It is usually done when doing a partial boil. For example, making a 5 gal batch but only boiling 3 gal and then topping up with 2 gal of water.
By reducing the specific gravity of the boiled wort, the hop utilization is increased and the darkening of the wort is reduced.

Ah, okay. Thanks! We’ve been talking about your answer this week and since we don’t know how much difference that makes, sometime this Spring, we want to do two boils side by side for comparison. Should we buy two 5-gal batches or would the test results be sufficient if we were to simply split up a 5-gal LME brew kit?

[denny]

@mainebrewer

It is usually done when doing a partial boil. For example, making a 5 gal batch but only boiling 3 gal and then topping up with 2 gal of water.
By reducing the specific gravity of the boiled wort, the hop utilization is increased and the darkening of the wort is reduced.

Ah, okay. Thanks! We’ve been talking about your answer this week and since we don’t know how much difference that makes, sometime this Spring, we want to do two boils side by side for comparison. Should we buy two 5-gal batches or would the test results be sufficient if we were to simply split up a 5-gal LME brew kit?

Splitting one kit would actually be better to ensure that the wort composition is exactly the same.

[system]

@denny

Splitting one kit would actually be better to ensure that the wort composition is exactly the same.

Great to know! Thanks for the clarification.  8)

[system]

@""

Going back to your original post, if you’re looking at continuing with extract-based brewing for a while, you may want to get a copy of the 4th edition of How To Brew.  There is a lot of good information on the ‘hows’ and ‘whys’ of partial boils and late extract addition.  Chris Colby also writes about late extraction additions here: http://beerandwinejournal.com/late-malt-extract-addition and in his new (Dec 2017) book.

If you are thinking of experimenting with SRM in those extract batches, here are a couple of links that may be helpful:

• estimating SRM: https://www.homebrewersassociation.org/forum/index.php?topic=29885.msg392903#msg392903
• LME darkens over time: Secrets to Keeping your Liquid Extracts Fresh - Brewing With Briess
• article on color impact with late additions of DME: LLCPedia - Your Business, Your Way
• Dave Tayors’s tips for excellent extract beer: extract - beginner rules of thumb2 | David Taylor | Flickr

Thanks for those resources! I glanced at them and will look at them in more detail soon. BTW, the 3rd link you mentioned was a dead link.

[system]

@""

…  BTW, the 3rd link you mentioned was a dead link.

Fixed (and thanks for letting me know).

Awesome! Thanks. It looks like a fun read. =:)