ginger beer recipe !!

I took this recipe from HBT. I thought maybe its some sort of braggot??
Also the recipe says i need to add enough water to get a boil of 6.42gal?? That seems a little extra only because is there a possibility of that much water being burned off??? This is a five gallon boil.

Ingredients for Mashing
Amount Item Type % or IBU
4.00 lb Pale Malt (2 Row) US (2.0 SRM) Grain 48.48 %
1.25 lb Cara-Pils/Dextrine (2.0 SRM) Grain 15.15 %


Single Infusion, Medium Body, Batch Sparge

Step Time Name Description Step Temp
60 min Mash In Add 7.88 qt of water at 164.0 F 154.0 F

Drain Mash Tun
Batch Sparge Round 1: Sparge with 5.33 gal of 175.0 F water

Boil Wort

Add water to achieve boil volume of 6.42 gal

Estimated pre-boil gravity is 1.040 (note this estimate includes honey)

Boil Ingredients

Boil Amount Item Type
60 min 1.50 oz Cascade [5.50 %] (60 min) Hops
60 min 3.00 lb Honey (1.0 SRM) Sugar
30 min 2.00 items Lemon Juice (per lemon) (Boil 30.0 min) Misc
30 min 6.00 oz Ginger Root (Boil 30.0 min) Misc
15 min 1.00 tsp Irish Moss (Boil 15.0 min) Misc
10 min 2.00 oz Ginger Root (Boil 10.0 min) Misc
10 min 2.00 items Lemon Zest (Boil 10.0 min) Misc
2 min 1.00 oz Williamette [5.50 %] (2 min) Hops

Cool and Prepare Fermentation

Cool wort to fermentation temperature

Transfer wort to fermenter
Add water to achieve final volume of 5.00 gal

Ingredients for Fermentation
Amount Item Type % or IBU
1 Pkgs Safale (DCL Yeast #US-05) Yeast-Ale

Fermentation

Primary fermentation (14 days at 68.0 F)
Secondary fermentation (7 days at 68.0 F)
Add to Secondary

Amount Item Type % or IBU
2.50 oz Ginger Root (Secondary 7.0 days) Misc

What are your goals with the ginger beer?

I've made 3 beers with ginger so far, each with 2-3 ounces fresh grated ginger root, half at 15 min & half at knock out. I really like the "moderately string ginger smell with hint of ginger flavor."
8 ounces might be a ginger hammer, which might be your goal