Keg Connection New Inline Flow Control Valve Giveaway

Home Brew Forums > Home Brewing Beer > General Techniques > Calculations: Dual Boil Evaporation Rate
Thread Tools
Old 12-12-2012, 06:29 AM   #1
Feedback Score: 0 reviews
Join Date: Mar 2012
Location: Mesa, Arizona
Posts: 44
Liked 2 Times on 2 Posts
Likes Given: 2

Default Calculations: Dual Boil Evaporation Rate

Im currently running a dual boil after I collect my runnings, and I feel like I'm missing my post boil volumes. If my batch is being split to ~3/gals a pot(x2 5gal pots) should I change my evaporation rate to double?

Right now in BeerSmith Im set at .5 gal/hr evaporation, but if I'm boiling in two pots should it be up'd to 1 gal/hr? I dont know, it might just be me and the numbers not playing out right in my head, but any insight into this would helpful.


JoshJoshua is offline
Reply With Quote
Old 12-12-2012, 07:25 AM   #2
Feedback Score: 0 reviews
Join Date: Apr 2009
Location: Seattle, WA
Posts: 826
Liked 32 Times on 30 Posts


Your boil rate is going to partially depend on the size of your pots, so going from one bigger pot to two smaller pots would probably increase the boil off. I don't know that it would necessarily be twice as much, but its certainly something you're going to have to figure out. For now, figure out how far off you're batches are currently, and change the beersmith settings to reflect what its looking like. You might have to change it around a little bit after a few batches to dial in your system, but then you should be fairly good.

erikpete18 is offline
Reply With Quote
Old 12-12-2012, 08:06 AM   #3
Feedback Score: 0 reviews
Join Date: Sep 2009
Location: Papamoa, New Zealand
Posts: 3,655
Liked 287 Times on 229 Posts
Likes Given: 57


You should boil 3 gallons in each pot for an hour, the same way you would do your beer. Check how much has evaporated from each pot... that is you boil off rate for each pot.
mattd2 is offline
Reply With Quote
Old 12-12-2012, 02:12 PM   #4
Dave the Brewer
Feedback Score: 0 reviews
Dave the Brewer's Avatar
Join Date: Sep 2007
Location: Nederland, TX
Posts: 253
Liked 6 Times on 5 Posts


.5 gal/hr sounds like a mild boil in any pot to me, I would think with two pots you would be losing atleast 1 gal/hr. The best thing to do would be to do what Matt said and boil 3 gals of water in each pot for an hour as an experiment to find out your evaporation rate.
My Single Tier HERMS "The Monk"
Dave the Brewer is offline
Reply With Quote
Old 12-12-2012, 03:01 PM   #5
Vendor and Brewer
Vendor Ads 
Feedback Score: 4 reviews
Bobby_M's Avatar
Join Date: Aug 2006
Location: Whitehouse Station, NJ
Posts: 22,889
Liked 1367 Times on 898 Posts
Likes Given: 35


If you're achieving a good rolling boil, I'd expect at least .75-1 gallons per hour per pot so start with about 3.5g per pot. Boiloff has a lot to do with wort surface area and yes, two 5g pots will have more surface than one 10g.

Welcome to I love you.
New 100% Stainless Steel Heating Elements are IN! ULWD 5500w Ripple, 2000w, 1500w, etc
Chugger Pumps, Pump Kits, Camlocks, Sightglasses, Clear USA made Silicone Tubing, RIMS, Electric Install Parts, etc.
Bobby_M is offline
Reply With Quote

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
What's an accurate evaporation rate for the hour long boil? Tankard All Grain & Partial Mash Brewing 43 06-25-2015 08:17 PM
Can you control the evaporation rate in a boil? LarryC General Beer Discussion 3 05-26-2012 04:27 PM
Consequences of a very high evaporation rate and/or boil off Geordan Equipment/Sanitation 7 03-13-2012 02:54 PM
Rate of evaporation? thomasgorff All Grain & Partial Mash Brewing 5 12-10-2011 07:29 AM
Evaporation rate mojotele Beginners Beer Brewing Forum 3 01-07-2010 03:43 AM

Forum Jump

Newest Threads