Partial boil question

[amishland]

Ok it seems self explanatory with the title "partial boil", but I have some questions. I have read that you make a portion of the total batch volume into a concentrated wort (~2.5L) and mix it with water to get to final desired volume (5gal). the cooled water not included in the wort helps lower the temp of the wort with out the aid of an IC, and it helps oxygenate the wort

how much wort evaporates during the process, and how do I know how much to put in the brew pot (I own a 4 gal (16Qt) Stainless pot). I understand that this is depending on the recipe and the method chosen (i.e. small steep / large boil / late extract or full boil .....)

Do I need to boil the water that gets added to the wort? Or only boil the wort?

And how much time should be spent mixing the concentrated wort with the plain old h20?

Thanks

 

[loopmd]

I partial boil about 3 gallons and then add ice along with cold water after the boil. I don't boil the water first, just add it to the hot wort. Mix it up vigerously for about 30 seconds to 1 minute will do the trick.


loop

 

[homebrewer_99]

Prior to brewing I place 4 - 1 gal jugs of PUR filtered tap water in the freezer for 4-5 hours.

I only boil 1.5 gals and add 1 lb of malt to the pot. Boil 45 mins, remove from flame, add remaining malts and steep for 15 mins.

Top off primary to 5.25 gals. Since the freezer water was not boiled it's full of oxygen and there's no need to go hog wild aerating. It's done when you pour it into the primary.

But, that's only one way to skin this cat...

 

[Rick_R]

I buy drinking water and use it to make my beer. I put 3 gallons (~11 liters) in the refrigerator when starting out and boil just over three gallons (~11.5 liters). When the wort is chilled to around 80 degrees F, I first pour the the refrigerated water into the carboy then add the wort. Comes out around 68 degrees F.

It's obviously dependent on your refrigerator, though, and how long you take to brew. On the first couple of batches I poured two gallons of cold water and added the wort. Then, depending on the temperature of the wort, either added another gallon cold water or a room temperature gallon of water. Since it was always the cold one I just throw in three gallons cold to start now.

I don't boil it, but if I used out of the tap I would. I aerate by putting a piece of plastic wrap over the lid held tight with a couple of rubber bands (kinda folded back on itself), then capped with a rubber carboy cap. I lay it on the side and shake the snot out of it.

Rick