1-1/2 Gallon boil vs. 2-1/2 Gallons

[TonyK]

I have been brewing with Mr.Beer kits. Im thinking about moving up to 5 gallon batches. Most of the instructions I have read, indicate that for 5 gallon extract batch you begin with a 2-1/2 gallon boil. add the remaining 2-1/2 gallons to fermenter once boil has been completed.
My question is this, could you possibly achieve the same result with a 1-1/2 gallon wort boil, and then add 3-1/2 gallons of water to the fermenter. Thanks for your attention. TonyK

 

[JetSmooth]

You could do that, but the hop utilization would be off because of the denser wort.

 

[JJL]

You could, but with wort boils that small, you can risk burning your wort alot more easily because there is a higher sugar to water ratio in the pot. Also, with evaporation, you will likely have a pretty syrupy wort once the boil is finished. It will definitely be darker because the wort will caramelize. The hops utilize will theoretically be reduced (meaning you would need to add more hops per gallon to get the bitterness you want).