Author Topic: Boil off percentage  (Read 1044 times)

Offline BrewBama

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Re: Boil off percentage
« Reply #15 on: June 26, 2018, 02:35:56 PM »

FWIW, I start with a 7 gallon pre-boil, 60 min low vigor boil (boil off around 8%) and finish with a 6.5 gallon post boil. I transfer 5.5 gallons crystal clear wort into the fermenter leaving behind trub/hops and get 5 gallons into my kegs.

^^^^  That's what I'm struggling to achieve.
“From man’s sweat and God’s love, beer came into the world.” — St. Arnold

Brewed in the Tennessee Valley. Rocket City — Huntsville AL

Offline hopfenundmalz

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Re: Boil off percentage
« Reply #16 on: June 26, 2018, 03:04:59 PM »
Boil off percentage has little to do with LODO. However, it does have a strong relationship to wort damage and premature staling of the finished beer. While evaporation losses as small as 2% have been cited in technical literature as producing acceptable beer, I question the study and its results. It appears that 6% to 10% is a more practical and workable target for Pro's and Homebrewers. I regularly limit my evaporation to 8% in a 60 minute boil and don't have issues with DMS. I was at 17% previously...OK, I didn't have DMS problems then either...even when brewing 100% pils grists.

Covering your kettle during the initial boil period and reducing your heat input make it possible to reduce evaporation losses and heat stress on your wort. Uncovering your kettle and conducting a modest and open boil for the later stage of your boil is also important. Volcanic boils are not helpful or useful.

I'm giving a comprehensive presentation on exactly this subject this Friday at HomebrewCon in Portland. AHA members should be able to view the presentation in a few months. There is a lot more to this than I've mentioned above.

A presentation I wanted to see, so I signed up to introduce you.
Jeff Rankert
Ann Arbor Brewers Guild
AHA Governing Committee
BJCP National
Home-brewing, not just a hobby, it is a lifestyle!

Offline ynotbrusum

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Re: Boil off percentage
« Reply #17 on: June 26, 2018, 04:20:09 PM »
Thanks for the replies. I've been stuck on the whole idea of boil off percent. Reducing the boil off by reducing the vigor and keeping the lid on for part of the boil is definitely in my future. I will strive to reduce the boil off as much as possible. I am also changing other parts of my process to reduce oxidation.
I'm also looking forward to Martin's presentation once it is released.

Sent from my Pixel 2 XL using Tapatalk

FWIW, I start with a 7 gallon pre-boil, 60 min low vigor boil (boil off around 8%) and finish with a 6.5 gallon post boil. I transfer 5.5 gallons crystal clear wort into the fermenter leaving behind trub/hops and get 5 gallons into my kegs.

I think you need to change your moniker to "Brewinlowvigor" now.  Just kidding, but those are obtainable numbers, for sure - other than the occasional instance where my boil is achieved more quickly than expected and I quickly lower it (electric brewing is so easy to monitor the approach to full boil temp - as long as you watch it!), I am also an adoptee of the low thermal stress approach advocated by Bryan and Brandon and their LOWO2 crew.  Adjusting volume to get the right "net into the fermenter" is key.

I will anxiously await the posting of the NHC presentations, as sadly, I will be missing this one in Portland.

Have fun up there in Beervana, forumites.
Hodge Garage Brewing: "Brew with a glad heart!"

Offline brewinhard

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Re: Boil off percentage
« Reply #18 on: June 26, 2018, 05:34:18 PM »
Thanks for the replies. I've been stuck on the whole idea of boil off percent. Reducing the boil off by reducing the vigor and keeping the lid on for part of the boil is definitely in my future. I will strive to reduce the boil off as much as possible. I am also changing other parts of my process to reduce oxidation.
I'm also looking forward to Martin's presentation once it is released.

Sent from my Pixel 2 XL using Tapatalk

FWIW, I start with a 7 gallon pre-boil, 60 min low vigor boil (boil off around 8%) and finish with a 6.5 gallon post boil. I transfer 5.5 gallons crystal clear wort into the fermenter leaving behind trub/hops and get 5 gallons into my kegs.

I think you need to change your moniker to "Brewinlowvigor" now. 

Ha!  Hmmmmm.....I may need to think about that for a bit!  :D