Author Topic: Preboil Gravity off  (Read 2472 times)

Offline Mark G

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Re: Preboil Gravity off
« Reply #15 on: April 15, 2013, 02:25:23 PM »
To be perfectly honest, if my preboil gravity and volume are on target, I don't even bother checking again postboil. I know how much water boiled off, and the sugars aren't going anywhere, so why bother.
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Offline duboman

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Re: Preboil Gravity off
« Reply #16 on: April 15, 2013, 02:31:45 PM »
I always take a pre-boil reading as it only takes a minute but I really don't lose sleep on it.If it's a little low I'll just adjust the boil a bit. Since I started adjusting my water and milling my own grain I have found that I 'm always 80% efficient in the mash/lauter and have been using the same equipment for over two years so I'm pretty dialed in. I guess I just keep doing it out of habit:D
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Offline malzig

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Re: Preboil Gravity off
« Reply #17 on: April 15, 2013, 05:55:35 PM »
To be perfectly honest, if my preboil gravity and volume are on target, I don't even bother checking again postboil.
Same here.  I used to check, but my post-boil gravity was always what the pre-boil gravity and volume predicted it to be.  I think the pre-boil gravity is the second most important, since that is your best chance to correct the hopping rate if the gravity is off.  First is the mash gravity, since that tells you that your mash has fully converted and that your gravity expectation will be met.

Once you know your system, the kettle volume should be a given.  You know how much water you put in, you know your dead space, and you know how much grain you used, therefore your absorption.  It shouldn't be much of a mystery.  I measure the kettle volume just to confirm that it is the volume I expected.

Offline tschmidlin

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Re: Preboil Gravity off
« Reply #18 on: April 16, 2013, 01:49:53 AM »
Also, I've found a preboil gravity reading to be utterly useless and a complete waste of time.
I agree if by "preboil" you mean before the boil, which it pretty much translates as.  I found I was not getting good mixing and any "preboil" gravity reading was off.

Now I take my "preboil" reading at the hot break, which is preboil as far as the hops are concerned but means it has been mixing for a while and gives me much nicer results.  I start timing my boil from there.
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Offline malzig

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Re: Preboil Gravity off
« Reply #19 on: April 16, 2013, 02:41:39 AM »
Now I take my "preboil" reading at the hot break, which is preboil as far as the hops are concerned but means it has been mixing for a while and gives me much nicer results.
Yes, it is a lot easier to get a fully mixed sample at boiling.  It's also easier to get an accurate kettle volume at this point, since you know the volume expansion is 4% at 212F.

Offline Mark G

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Re: Re: Preboil Gravity off
« Reply #20 on: April 16, 2013, 05:13:23 AM »
Also, I've found a preboil gravity reading to be utterly useless and a complete waste of time.
I agree if by "preboil" you mean before the boil, which it pretty much translates as.  I found I was not getting good mixing and any "preboil" gravity reading was off.

Now I take my "preboil" reading at the hot break, which is preboil as far as the hops are concerned but means it has been mixing for a while and gives me much nicer results.  I start timing my boil from there.
Good point. I also wait until the beginning of the boil to take the "preboil" reading.
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Offline topher.bartos

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Re: Preboil Gravity off
« Reply #21 on: April 30, 2013, 11:58:04 AM »
Are you taking into account temperature?? Higher temperatures will lower the gravity by a few points.
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