I plugged this into Beer Smith. Here is a copy of the relevant info from the print out. This is at a 1.25 qt of water per lb. of grain. Cliff's notes--prep about 7 gallons of brewing water. Mash in with 2.66 gallons of water for 60 minutes. Sparge (read-move bag to pot and teabag a few times, let rest 10-15 minutes, tea bag a few more times, let drain through a colander) in about 4 gallons of water at about 168*. Top up to around 5.72 gallons or whatever your preboil volume usually is to achieve 5 gallons post boil.
Continue as normal with hop additions. Add extract with 15 minute hops additions for late extract or at beginning of boil if that is what you like to do.
Hope this helps. Beer Smith is $20 and a must if you are going to start doing partial mash or all grain.
If you don't mind a little critique of your recipe, there seems to be an awful lot of crystal/ specialty grains. Personally, I would probably scale back a little and simplify so you can tell where your flavors are coming from. What recipe is this and what is your hop schedule?
Good Luck and don't hesitate to ask any more questions. This mash schedule is default set at 150* which will create a pretty fermentable wort, though that will be offset to a certain extent by the extract. You have included dextrine malt which will help with mouthfeel/ body/ head retention. If you like a slightly sweeter brew, up the mash temp by as much as 5 or 6*
Prepare 6.74 gal Water for Brewing
Mash or Steep Grains
Ingredients for Mashing Amount Item Type % or IBU
4.0 oz Rice Hulls (0.0 SRM) Adjunct 2.38 %
4 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 42.86 %
1 lbs 8.0 oz Rye Malt (4.7 SRM) Grain 14.29 %
12.0 oz Caramel/Crystal Malt - 40L (40.0 SRM) Grain 7.14 %
12.0 oz Caramunich Malt (56.0 SRM) Grain 7.14 %
4.0 oz Aromatic Malt (26.0 SRM) Grain 2.38 %
4.0 oz Cara-Pils/Dextrine (2.0 SRM) Grain 2.38 %
4.0 oz Caramel/Crystal Malt -120L (120.0 SRM) Grain 2.38 %
Single Infusion, Medium Body, Batch Sparge
60 min Mash In Add 10.63 qt (2.66 gal) of water at 161.4 F 150.0 F
Batch Sparge Round 1: Sparge with 4.08 gal of 168.0 F water
Add water to achieve boil volume of 5.72 gal
Estimated pre-boil gravity is 1.052