Adding water post-boil...
#1
Posted 15 April 2009 - 07:12 AM
#2
Posted 15 April 2009 - 07:23 AM
#3 *_Guest_Blktre_*
Posted 15 April 2009 - 07:27 AM
Edited by Blktre, 15 April 2009 - 07:29 AM.
#4
Posted 15 April 2009 - 07:32 AM
#5
Posted 15 April 2009 - 08:24 AM
Would this throw off my gravity numbers? Why can you add water to top-off with extract brewing and not all-grain?Feel free to add water after the boil if necessary, as long as you're reasonably sure it's clean. Add it before chilling, especially, and the whole thing will still be hot enough to be sterile.
#6
Posted 15 April 2009 - 08:54 AM
See my post above.Would this throw off my gravity numbers?
You can with all grain it's just that you usually don't need to. You design everything so that you come out with the right gravity at the end without topping off. With extract, particularly with a concentrated boil, you need to top off to dilute to the right gravity.Why can you add water to top-off with extract brewing and not all-grain?
#7
Posted 15 April 2009 - 09:19 AM
#8 *_Guest_Blktre_*
Posted 15 April 2009 - 09:52 AM
#9
Posted 15 April 2009 - 10:11 AM
Well, yeah there's no need to keep a raging boil going once you get it up to the boiling point. I cut my fire down quite a bit to maintain a good solid rolling boil but not a violent one.I've got a 7 gallon brewpot that I fill with wort. I just can't believe my evaporation rate! I guess I need to bring to a boil and then reduce the heat just a tad.
#10
Posted 15 April 2009 - 01:10 PM
#11
Posted 15 April 2009 - 04:56 PM
You're right, it will affect IBU's. It will bring them back where they were planned to be.IBU's are a unit of concentration and follow the same equation you've listed above. If you boil down below the planned volume, gravity will go up but so will IBU's. You likely won't notice because the balance will still be the same. Similarly, if you dilute to get the OG you'd planned, you'll also be diluting the IBU's, still maintaining the balance.If you add water post-boil to try and fine tune your gravity or volume, it will affect your IBU's, though if it's a small amount it might not be noticeable.Keep track of your boil-off rate - I get 2-2.2 gal/hr in my 15 G pot and adjust your water accordingly in the mash and sparge.I worry more about my S.G. than volume, so I make a quick calculation pre-boil (and thus pre-hops) to make sure I'm on track to hit my gravity. If I'm going to be low, I boil longer, if I'm going to be high I add water. (and tweak the hops accordingly)Preboil gravity X Preboil volume = Postboil gravity X post boil volume and Preboil volume - boil time X boil-off rate = Postboil volume.One more good reason to get that refractometer - calculations are easier in Brix/Plato
#12 *_Guest_Blktre_*
Posted 15 April 2009 - 06:18 PM
That's the theory. As i stated earlier, i don't 100% buy into it. There are alot of factors that can effect the balance. And topping up a messed up full boil imo is just another factor of fixing something that may just be putting a band aid on it. I don't care what some math ratio says. The proof is in the taste.You're right, it will affect IBU's. It will bring them back where they were planned to be.IBU's are a unit of concentration and follow the same equation you've listed above. If you boil down below the planned volume, gravity will go up but so will IBU's. You likely won't notice because the balance will still be the same. Similarly, if you dilute to get the OG you'd planned, you'll also be diluting the IBU's, still maintaining the balance.
#13
Posted 15 April 2009 - 06:35 PM
#14
Posted 16 April 2009 - 06:15 AM
True, but the wort gravity is higher at the end - where hop utilization is low anyway.I haven't dealt with this problem in a while. But, IIRC you will get less utilization with a higher gravity wort. If I was stuck with this I would continually add to the boil to maintain volume and hopefully not screw up my IBUs. Of course at my place if I overshoot IBUs it's something I will happily deal with. With a post boil top off you're dealing with the opposite....
#15
Posted 16 April 2009 - 08:04 AM
This is interesting! What about adding more water during the boil? Maybe at the 30 minute mark?If I was stuck with this I would continually add to the boil to maintain volume and hopefully not screw up my IBUs. Of course at my place if I overshoot IBUs it's something I will happily deal with. With a post boil top off you're dealing with the opposite.
#16
Posted 16 April 2009 - 08:40 AM
#17
Posted 16 April 2009 - 08:48 AM
Would you recommend adding a little bit of water every few minutes into the boil or adding another gallon, let's say 30 minutes in? Or would it not matter?First off, even though some regard it as a poor example, Bud brews and ferments at 1.080. Then they post fermentation water it down 50% to an effective 1.040 OG. Any off flavors will certainly show up in their brand of water.My Irish red is a 23 gal batch. I dial that into promash with a 13.5 gal wort size. PM bumps the hop addition as it utilization goes down as SG goes up. However in your case utilization, which occurs mostly in the first 30 minutes, probably isn't affected.Water away!
#18
Posted 16 April 2009 - 08:55 AM
I think you're overthinking it. It doesn't really matter. But the first thing I'd try is cutting back on the flame to reduce your evaporation rate.Would you recommend adding a little bit of water every few minutes into the boil or adding another gallon, let's say 30 minutes in? Or would it not matter?
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users