First Brew Completed...Questions

Post #1 made 9 months ago
Hi All,

So I have done my first BIAB brew, thoroughly enjoyed it, Fullers London Porter from Graham Wheelers book. I am going to make this into a plum porter using plum extract so I will let you know how that turns out.

I was just wondering what the reason is for a 90 minute mash, I know a few AG brewers and they mash, in a separate mash tun, for 60 mins? Is it because we are mashing and sparging at the same sort of time?

The same question about the boil, do any of you boil for just 60 mins? If you do have you seen much difference in the brew on a 60 minute boil against a 90 minute boil?

I have also noticed on BIABacus that the boil time adjusts the grain bill, the longer the boil time the less grain, I would have thought it should be the mash time would adjust the grain bill?

I'm not trying to cut corners here just wanting to understand why the differences in the mash and boil times for BIAB compared to my 3 vessel brewing friends who mash and boil at 60 minutes.

Thanks

Dan
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Re: First Brew Completed...Questions

Post #2 made 9 months ago
Hi Dan and congrats on your maiden voyage :salute:

In three-vessel brewing, it's not uncommon to mash for 60 minutes however, mashing is followed by sparging which can take 30 minutes or more. In single-vessel all-grain, as you say, we are mashing and sparging at the same time. Your grain bill's contact time with water is important as our tests have shown. While some grain bills will convert more quickly (don't use iodine tests), nearly all will result in better extraction with a 90 minute mash so it is a great safe time to work off.

90 minutes is also a safe time for the boil. A lot happens during the boil. Have a read of this article.

The BIABacus reduces your grain bill if you increase the boil time because of the following:
1. An increased boil time means increased evaporation.
2. Increased evaporation means you need more water to start with.
3. Increased water means you can "clean" your grain better*.
4. If you can clean your grain better, you need less grain to get the same result.

*Imagine a pair of very dirty, white jeans. Now put those jeans in a bucket with 10L of water, jiggle them around, squeeze them, and then hang them out to dry. If you did the same thing with a bucket full of 20L of water, which would give you the whiter jeans?

Hope that helps ;)
PP
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Re: First Brew Completed...Questions

Post #3 made 9 months ago
Hey Pat, some parts of this are gained from mash and other parts from boil. The heading sentence mentions increasing boil time but I believe two of your four points are actually from the longer mash time. So for clarity...
The BIABacus reduces your grain bill if you increase the boil time because of the following:
1. An increased boil time means increased evaporation. (Evaporation during Boil)
2. Increased evaporation means you need more water to start with. (Evaporation during Boil)
3. Increased water means you can "clean" your grain better*. (Clean during Mash)
4. If you can clean your grain better, you need less grain to get the same result. (Clean during Mash)
And your washing example would be from more water per grain during the mash, for better extraction and mash efficiency. (Not the boil).
    • SVA Brewer With Over 20 Brews From United States of America

Re: First Brew Completed...Questions

Post #5 made 9 months ago
Sorry Pat. Your info is always excellent, but some things were a little unclear to my reading (what process produces which benefit). :geek: Unless I am looking at the process wrong, or misunderstood (after days of computer problems), and either of these is possible... :dunno:
    • SVA Brewer With Over 20 Brews From United States of America
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