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Old 12-18-2010, 06:13 PM   #1
37OliveStBrews
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I brew exclusively through kits (AHS, NB, MW, and local HBSS) and up until now have always done partial boils with my partial mash kits. But I want to do a full boil since I have the capacity and I hear the beer tastes better.
Here is my question, why can't I just mash with more water to get my boil volume and follow the recipe as is since all I do is top off with water anyways?
Thanks.

 
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Old 12-18-2010, 06:29 PM   #2
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Originally Posted by 37OliveStBrews View Post
I brew exclusively through kits (AHS, NB, MW, and local HBSS) and up until now have always done partial boils with my partial mash kits. But I want to do a full boil since I have the capacity and I hear the beer tastes better.
Here is my question, why can't I just mash with more water to get my boil volume and follow the recipe as is since all I do is top off with water anyways?
Thanks.
In short, no.

Now, comes the explaination and still how to do a full boil.

Mashing requires enzymatic conversion, from starch to simple sugars. To do that, you need a certain pH in the mash and a certain temperature. That generally requires a mash of 1.25-2 quarts of water per pound of grain. Most people find that 1.25-1.5 quarts of water per pound of grain works best. The temperature range is variable, but 153-154 is a good basic temperature.

Then comes the sparge. Sparging is "rinsing" the grain of the rest of the sugars that were converted during the mash. You can sparge with up to .5 gallons of sparge water per pound of grain, without risking oversparging.

So, for a typical PM, say you have 5 pounds of grain.
5 pounds of grain x 1.5 quarts of water per pound= 7.5 quarts of water.
The grain will absorb about .125 gallons per pound- so you should get out 1.25 gallons of wort out of this mash.

For the sparge, you can use up to 2.5 gallons of water for the sparge. You won't have any more absorption, so you'll end up with 2.5 gallons out of the sparge.

At that point, you'd have 1.25 gallons (mash), and 2.5 gallons (sparge)= 3.75 gallons in the boil kettle. You can then top up to 6.25 gallons with water (or whatever your boil volume is), add your DME or LME and start your boil.

Adding water to the boil is fine, rather than oversparging your grains.
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Old 12-18-2010, 06:34 PM   #3
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Thank you Yooper for the great explanation. After poking around I found the reason why you wouldn't want to do what I proposed (tannins and other off tastes). So I guess I can still do the full boil with my mash schedule but will have to top off the water pre-boil. Thanks again for contributing.

 
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Old 12-18-2010, 06:34 PM   #4
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Yooper, Just curious what would over-sparging do? Release tannins or something?

EDIT: got it. Nevermind. :-)

 
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Old 12-18-2010, 06:37 PM   #5
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Yooper, Just curious what would over-sparging do? Release tannins or something?
Yes. The pH would rise. When we AG brewers fly sparge, we stop the runnings at 1.010 for that reason. Also, once you get that diluted, you're not getting much sugar out of the grain anyway.
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Old 04-14-2011, 04:28 AM   #6
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Thanks so much for this thread!

I just upped to a 40 QT kettle and propane burner and was searching for this very answer!

Thanks so much for this info.

Cheers

 
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Old 07-19-2012, 05:04 PM   #7
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The pH would rise by oversparging because you're introducing more water than necessary, and water has a pH of around 7-8, correct? I want to help clarify the mindset here for new AG brewers.

So let's say you're brewing via Partial Mash in a mesh bag (BIAB). And instead of sparging and mashing out in the traditional sense, you dip the entire grain bag (after the mini mash) in another kettle containing the remaining amount of plain water required by the full volume boil recipe at mashout temps. This sort of acts like a sparge and mashout together. You're rinsing the grain in a large volume of mashout temp water. But no more water is introduced than necessary... So what you have there is your start boil volume. But the wort is diluted by the water and requires additional Extract to reach target gravity. The low pH grain wort is buffered by the higher pH of water, but the extract combats this again by reducing the pH and then after the boil, the pH is even lower.

I want to keep this open for discussion so we don't confuse the partial mash brewers that go this route. Thoughts?

 
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Old 07-19-2012, 05:20 PM   #8
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Ahhhh, zombies!!!
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can i drink this? I mean. Im gunna. But is it fine?
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Old 07-19-2012, 05:39 PM   #9
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Oh, get over yourself. A few of you guys are so bothered by people resurrecting old threads

The thread was linked in a new 2012 post.

If we're all here to help each other then I don't see the problem. Thanks for your constructive input!!

 
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Old 07-19-2012, 05:41 PM   #10
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Oh, get over yourself. A few of you guys are so bothered by people resurrecting old threads

The thread was linked in a new 2012 post.
Huh? I'm just being silly, man. Ya know, zombies are fun, etc.... No need to get your undies in a bundle.
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can i drink this? I mean. Im gunna. But is it fine?
Quote:
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it's not a barley wine. it's an ale.
Quote:
Originally Posted by bottlebomber View Post
Have you seen the price of ketchup lately? And I'm not talking Heinz.

 
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