Happy HolidaySs Giveaway - Last Sponsor Giveaway of the Year!

Come Enter the BrewDeals/FastFerment Giveaway!


Home Brew Forums > Home Brewing Beer > General Beer Discussion > Why do I have a big difference in boil-off rate between 2 (6.6 and 3.5 gls) batches?
Reply
 
LinkBack Thread Tools
Old 06-16-2013, 12:21 PM   #1
Elysium
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2013
Location: Madrid, Spain
Posts: 1,057
Liked 20 Times on 20 Posts
Likes Given: 148

Default Why do I have a big difference in boil-off rate between 2 (6.6 and 3.5 gls) batches?

I have just finished my second BIAB brewing.

My pot is a 13.2 gallon steel pot, 15.74"-15,74" in dimensions.

My 1st batch (3.5 gallon planed, achieved too) started off with 6.6 gallons of water and I ended up with 3.4 gallons in the fermenter of which 1.5 gallon of water boiled off in 60 mins.

However...my second batch (6.6 gallon planed, achieved too) was a lot bigger.
I started off with 9.2 gallons of water and used 1.3 gallon of water to sparge (I didnt do it with my 1st batch..but the sparge water was planned when I calculated the amount of water needed), then I ended up with 6.8 gallons in the fermenter. Meaning only 0.8 gallon of water evaporated. The boil wasnt actually as fierce as during the 1st brewing....I guess it is due to the bigger batch size. So, this might explain why water didnt evaporate. I really dont know.

Is this possible that my boil off rate dropped this much just because of the size of the batches? Will this affect the taste of the final brew?

P.S. My calculation doesnt account for any water losses durning the brew...just the actual amount of water that is boiled off.

__________________
Elysium is offline
 
Reply With Quote Quick reply to this message
Old 06-16-2013, 12:55 PM   #2
novahokie09
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2012
Location: Centreville, VA
Posts: 183
Liked 32 Times on 16 Posts
Likes Given: 4

Default

You didn't evaporate as much water due to the boil's intensity.

Your burner was not providing enough heat to the large batch as it did to the 3 gallon batch, since the larger batch requires more heat to reach the same boil-off rate.

There will be a few differences. You will start with a lower gravity beer. Color development and hop utilization will occur less in a less aggressive boil. Also, you may have less hot break development as a result of lower boil intensity.

You're still making beer though.

__________________
novahokie09 is offline
 
Reply With Quote Quick reply to this message
Old 06-16-2013, 01:10 PM   #3
Elysium
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2013
Location: Madrid, Spain
Posts: 1,057
Liked 20 Times on 20 Posts
Likes Given: 148

Default

Quote:
Originally Posted by novahokie09 View Post
You didn't evaporate as much water due to the boil's intensity.

Your burner was not providing enough heat to the large batch as it did to the 3 gallon batch, since the larger batch requires more heat to reach the same boil-off rate.

There will be a few differences. You will start with a lower gravity beer. Color development and hop utilization will occur less in a less aggressive boil. Also, you may have less hot break development as a result of lower boil intensity.

You're still making beer though.
Thanks for the reply. Do you think the beer will be a lot different due to all the factors you mentioned (such as the hop utilization, less hot break..etc).
I understand that I am still making beer...but I dont wanna make low-quality beer. I'd rather lower the amount of water and make smaller, but better batches...probably that's the best option.
__________________
Elysium is offline
 
Reply With Quote Quick reply to this message
Old 06-16-2013, 01:20 PM   #4
novahokie09
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2012
Location: Centreville, VA
Posts: 183
Liked 32 Times on 16 Posts
Likes Given: 4

Default

Did you make the same beer in the larger batch? If so, just save a bottle from the smaller batch and see which you prefer. Some people might not even notice a difference. Better palates will be able to differentiate.

You can still make the bigger batches, but you need to realize your final volume will be larger due to less boil off. You can account for this a few ways. First, you can use the same volume of water, and increase your starting grains and increase your hopping amounts to arrive at the same color, IBU and OG. The other option would be to just start with less water in order to hit your target volume into the fermentor. This would require you to know your boil off rate and calculate how much pre-boil volume you will need. You could also just boil longer to get the OG you want.

This is all part of dialing in your system. Just stick with it and take ample notes. This will allow you to learn your system. If I were you'd, I'd just keep making larger batches but account for how your system works.

__________________
novahokie09 is offline
 
Reply With Quote Quick reply to this message
Old 06-16-2013, 01:23 PM   #5
wilserbrewer
BIAB Expert Tailor
HBT_SPONSOR.png
Vendor Ads 
Feedback Score: 9 reviews
 
wilserbrewer's Avatar
Recipes 
 
Join Date: May 2007
Location: Jersey Shore, Jersey
Posts: 7,144
Liked 541 Times on 444 Posts
Likes Given: 10

Default

Quote:
Originally Posted by Elysium View Post
Thanks for the reply. Do you think the beer will be a lot different due to all the factors you mentioned (such as the hop utilization, less hot break..etc).
I understand that I am still making beer...but I dont wanna make low-quality beer. I'd rather lower the amount of water and make smaller, but better batches...probably that's the best option.

Your larger batches will be of no less quality. You just need to account for the different amounts of boil off with different size batches.
wilserbrewer is online now
 
Reply With Quote Quick reply to this message
Old 06-16-2013, 10:56 PM   #6
Elysium
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2013
Location: Madrid, Spain
Posts: 1,057
Liked 20 Times on 20 Posts
Likes Given: 148

Default

Quote:
Originally Posted by wilserbrewer View Post
Your larger batches will be of no less quality. You just need to account for the different amounts of boil off with different size batches.
But surely the less intense boil affects the chemistry (I mean the things that change, boil off) inside the wort and the way things boil off. Or am I wrong?
__________________
Elysium is offline
 
Reply With Quote Quick reply to this message
Old 06-17-2013, 12:36 AM   #7
wilserbrewer
BIAB Expert Tailor
HBT_SPONSOR.png
Vendor Ads 
Feedback Score: 9 reviews
 
wilserbrewer's Avatar
Recipes 
 
Join Date: May 2007
Location: Jersey Shore, Jersey
Posts: 7,144
Liked 541 Times on 444 Posts
Likes Given: 10

Default

Quote:
Originally Posted by Elysium View Post

..my second batch (6.6 gallon planed, achieved too) was a lot bigger.
I started off with 9.2 gallons of water and used 1.3 gallon of water to sparge , then I ended up with 6.8 gallons in the fermenter. Meaning only 0.8 gallon of water evaporated. .
So on your second batch, you used 10.5 gallons of water total, yet ended with 6.8, and only evaporated .8 gallons? Where did the other 2.9 gallons go?

Are you boilng on a stove top?

You could try boiling the larger batches longer?
wilserbrewer is online now
 
Reply With Quote Quick reply to this message
Old 06-17-2013, 07:54 AM   #8
Elysium
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2013
Location: Madrid, Spain
Posts: 1,057
Liked 20 Times on 20 Posts
Likes Given: 148

Default

Quote:
Originally Posted by wilserbrewer View Post
So on your second batch, you used 10.5 gallons of water total, yet ended with 6.8, and only evaporated .8 gallons? Where did the other 2.9 gallons go?

Are you boilng on a stove top?

You could try boiling the larger batches longer?
grain absorption: 1.5 gallon, trub was a bit big: 1.3 gallon, and I think I had a bit of a shrinkage too. That's where the 2.9 gallon went.

I dont use a stove top.
I use 2 big gas rings that are attached to a gas cylinder. It's a thing they use here in Spain.
__________________
Elysium is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pitching rate for small batches? jdubb75 Fermentation & Yeast 3 02-01-2012 05:03 PM
Can this boil-off rate be right? fxdrider Beginners Beer Brewing Forum 11 09-27-2011 03:24 PM
Rate of Boil? What's best? Apoxbrew All Grain & Partial Mash Brewing 7 06-27-2011 06:33 PM
Boil kettle and boil off rate question jfkriege Equipment/Sanitation 4 12-11-2009 07:02 PM
Boil off rate hopsalot Beginners Beer Brewing Forum 4 02-26-2008 07:27 PM



Newest Threads

LATEST SPONSOR DEALS