Thoughts on boil-off rate?

[Bassman2003]

Sorry, I was lumping some things together. (why I am not a scientist!) Fast cooling to 176F then I guess a little slower might help get rid of a little more of the DMS that might have been created.

 

[Bigarcherynut]

I'm going to brew tomorrow and have decided to try and lower my boil-off rate. As I earlier mentioned my current rate is at 2.1 GPH. My test run got it down .6 GPH which is about 8%. My test run was with the lid partially on but have decided to do it without the lid. Question is, I'm going and try to duplicate the lower rate and I know what my finished amount of wort into the fermenter needs to be. I plan on watching the level till I hit my mark and my OG should be correct. I know if I boil longer it's not a problem but what if I boil less than my hour boil-off time? Hoping to be close to the correct time but lets say I'm only boiling for 45 minutes? Any issues with that. I'm brewing a Scotch Ale with a OG of 1.063.

Thanks and Happy Easter!!!

 

[Bassman2003]

I am unsure about exactly how short is too short. Folks do short and shoddy brews, so everything is on the table these days. But, most do not go under the 60 min mark. Especially if you might have a lot of pilsner malt. Using a software like Beersmith really helps in this situation.

 

[InspectorJon]

Hop bitting could go a little low with a shorter boil. That might not be particularly critical with your Scotch Ale. Boiling off a little extra and having a higher OG might not be bad for that style either.

 

[RPh_Guy]

I know if I boil longer it's not a problem but what if I boil less than my hour boil-off time? Hoping to be close to the correct time but lets say I'm only boiling for 45 minutes? Any issues with that.

Besides thermal stress, the boil length mainly affects two things: hop bitterness (utilization), and DMS removal.
Boiling hops for 45 minutes isn't too different from boiling them for 60 minutes, but any less and you'll start to see decreased bitterness and possibly increased flavor.
Speaking from experience, 45 minutes can definitely work with regard to DMS, but that'll depend on the recipe (e.g. amount of pilsner malt), and pH, and also the system because the amount of circulation matters.

 

[Bigarcherynut]

I am unsure about exactly how short is too short. Folks do short and shoddy brews, so everything is on the table these days. But, most do not go under the 60 min mark. Especially if you might have a lot of pilsner malt. Using a software like Beersmith really helps in this situation.

I'm not using any pilsner malt so that wont be a problem I have my program dialed in to hit a 60 minute boil but trying a different boil rate may impact this. I do use BS so that is helpful.

Thanks

 

[Bigarcherynut]

Hop bittering could go a little low with a shorter boil. That might not be particularly critical with your Scotch Ale. Boiling off a little extra and having a higher OG might not be bad for that style either.

Oh yes, forgot about the hop bittering. My current IBU's is 20.7 IBU's with a 45 minute boil would be 19.5 or 21.3 if I did an hour and 15 minute boil, so not excessive either way. Longer and higher a OG is never a problem with me.

Thanks!

 

[Bigarcherynut]

Besides thermal stress, the boil length mainly affects two things: hop bitterness (utilization), and DMS removal.
Boiling hops for 45 minutes isn't too different from boiling them for 60 minutes, but any less and you'll start to see decreased bitterness and possibly increased flavor.
Speaking from experience, 45 minutes can definitely work with regard to DMS, but that'll depend on the recipe (e.g. amount of pilsner malt), and pH, and also the system because the amount of circulation matters.

I think the thermal stress issue is what lead me to this thread. As you can see by my earlier post, I boiled at max output on my E-kettle and my boil off rate was 2.1 GPH. After reading this thread and another was ready to scale down but then a link that was posted here, stilled said the vigorous boil is the way to go. Confused but willing to try the mild boil.

Ran the numbers on my IBU's and I should be fine either way with a shorter or longer boil time.

For what I have read lately on DMS removal, I'm hoping I'm long enough. I also read conflicting things in regards with DMS removal. I'm going to stay with a slow boil, but will remove the cover even though I have read, the cover remaining on the pot has nothing to do with the removal of DMS. It sounds as if it's a chemical change not due to evaporation. I guess I will need to read further on that subject. I'm not using pilsner malt and work hard at my pH numbers so that should stay in check. I have an oval pot and circulate during my boil which many don't understand and are against but always have a never had a problem with my pump.

I'll see how this works this time. Greatly appreciate your input.

 

[Dog House Brew]

I’ve really not seen any dramatic drop in bitterness. I haven’t changed my recipes much.

 

[Brewbuzzard]

I guess I was mostly wondering what y'all thought about the effects of boil-off rate and what it does to the finished beer. It seems that some people believe even what is considered an average rate (1-1.5gph) can have detrimental effects on finished beer such as poor head retention, mouthfeel, and shelf stability.

I use to get about 14% evaporation rate with my gas rig and the same with my electric rig. Important key here is the same kettles I just installed elements and a control panel. I had winning beers with both. I installed a steam Slayer from Brew Hardware and now my evaporation rate is 5% . My beers are still winning big time. All my beers had good head retention and the body fits the style. I also always boil for an hour and a half. Just giving food for thought.

 

[Brewbuzzard]

I would love to see what type of boil they employ in a mega brewery that makes the watered down stuff like Budweiser, and their numbers, since in order to make that beer have perfect balanced taste and be consistent as it is they are probably doing things right.

Taste???

 

[Hwk-I-St8]

Thanks for the links and info. The Wiki points to the cooling stage as being what is most important. DMS always gets associated with boiling but boiling is going to happen no matter what and the DMS evaporates quite easily at brewing temperatures. SMM is really the culprit and its breakdown is more associated with boiling temps.

Key takeaways:

SMM is largely not broken down into DMS until the boil
High pH in the boil helps this conversion
Reinforces the practice of higher pH through the mash & boil and lowering pH right at the end of the boil
DMS will be evaporating all the way through until sub-99F is reached (huge boil not needed)
Chill to 140F and below quickly as SMM is still being converted but DMS also needs motion to be "pushed" out of the wort

You're last point is problematic if you want to whirlpool hop additions.

 

[RPh_Guy]

You're last point is problematic if you want to whirlpool hop additions.

See my response to that post. That reason is specifically why I corrected him.

 

[Hwk-I-St8]

See my response to that post. That reason is specifically why I corrected him.

Yeah, I saw that after I posted. That's good as I typically WP at 170 or lower.

 

[Jordan Logo]

This topic is quite interesting to me...

Do you guys measure your pre-boil volume RIGHT before your boil? And do you guys measure your post-boil volume RIGHT after boil is over, or right before you transfer to fermenter?

According to BeerSmith's settings there is a 4% difference between cold and hot wort.

 

[Franktalk]

Right after boil, as the amount into the fermenter is going to vary according to losses in chilling the wort and transfer into the fermenter. You want to know how much boiled off from the start of the boil to the end; that's all.

 

[Bigarcherynut]

This topic is quite interesting to me...

Do you guys measure your pre-boil volume RIGHT before your boil? And do you guys measure your post-boil volume RIGHT after boil is over, or right before you transfer to fermenter?

According to BeerSmith's settings there is a 4% difference between cold and hot wort.

When I first began BIAB brewing, I was asking for help on hitting my numbers and everyone posted to take Good Readings!!! I continue to do that and in my own program I developed. I actually have estimated levels for pre, post and levels into my fermenter so I have ideas when I don't hit my level and what caused it. I also added in the estimated hot level values so I know what to expect. Some will say over kill but like playing with home brewing, I like playing with that along with my own software program fitted for my unique E-kettle.

 

[RPh_Guy]

This topic is quite interesting to me...

Do you guys measure your pre-boil volume RIGHT before your boil? And do you guys measure your post-boil volume RIGHT after boil is over, or right before you transfer to fermenter?

According to BeerSmith's settings there is a 4% difference between cold and hot wort.

Good point.
I measure volume after lautering and throughout the boil. I adjust all my measurements to room temp.

 

[VikeMan]

Just to add 2 cents to an already long thread, I have been doing gentle boils for over a decade. I'm totally unconvinced by people who say you need a "vigorous" boil for a good hot break, hop utilization, and elimination of DMS. IMO, Keeping the wort at 212F and moving are key. Wort jumping out of the kettle isn't key.

 

[Big Monk]

Just to add 2 cents to an already long thread, I have been doing gentle boils for over a decade. I'm totally unconvinced by people who say you need a "vigorous" boil for a good hot break, hop utilization, and elimination of DMS. IMO, Keeping the wort at 212F and moving are key. Wort jumping out of the kettle isn't key.

THIS!

 

[Die_Beerery]

I'm here to just say how I love people citing Bamforth from years prior. Because now a days, he's completely on the other side of the fence. This should be a lesson to folks. People no matter how full of "credit" or sure of themselves they are, doesn't mean they are in the least bit, correct. Time is a great denominator for that.

 

[VikeMan]

I'm here to just say how I love people citing Bamforth from years prior.

To be fair, Bamforth did use the term "vigorous boil" in a video once. It was, like, an OFFICIAL INTERVIEW.

 

[Die_Beerery]

To be fair, Bamforth did use the term "vigorous boil" in a video once. It was, like, an OFFICIAL INTERVIEW.

Oh's hes said it more than once!

 

[Cavpilot2000]

Just to add 2 cents to an already long thread, I have been doing gentle boils for over a decade. I'm totally unconvinced by people who say you need a "vigorous" boil for a good hot break, hop utilization, and elimination of DMS. IMO, Keeping the wort at 212F and moving are key. Wort jumping out of the kettle isn't key.

And the beauty of it is, whether your wort is just barely simmering or is jumping out of the kettle with a ludicrous level of vigor, it's still at 212F.
For some reason people seem to think a hard boil is getting that liquid hotter, but it isn't because, well, physics and stuff.

 

[Big Monk]

To be fair, Bamforth did use the term "vigorous boil" in a video once. It was, like, an OFFICIAL INTERVIEW.

People owe it to themselves to get Bamforth's "Freshness". If you want a handle on the man's opinions currently, it's a great read and has a lot of good info in it.

 

[Die_Beerery]

People owe it to themselves to get Bamforth's "Freshness". If you want a handle on the man's opinions currently, it's a great read and has a lot of good info in it.

Or check his current position of employment

 

[Punjom]

Great Topic! I’ve boiled on very high heat for over 20 years. I’ve brewed a few batches since reading this blog with low boil and had much better results. 20 gal yield with 1.5 gal evap today (was 2.5).

 

[Bigarcherynut]

And the beauty of it is, whether your wort is just barely simmering or is jumping out of the kettle with a ludicrous level of vigor, it's still at 212F.
For some reason people seem to think a hard boil is getting that liquid hotter, but it isn't because, well, physics and stuff.

I have been following this post in hopes to lower my boil-off rates from 2.1 Gal/Hr. to a lower level which I'm doing by lowering my power output to the electric element. My boiling action went from very rigorous to a mild movement of the liquid. I have partially covered my kettle, to leaving it fully open. What I have found is my water temp dropped from 212 at very intense water action with 100% power output to the element, to 206 degrees with my output at 40% output with a lower action as if it's simmering. I'm not here to disagree with your post but I don't think you can turn down the heat whether using electric or gas flame to a point that you have water movement which some are calling a low boil or whether it's called a simmer and maintain 212 degrees. I'm going to continue to start with a very rigorous boil then turn my heat down to maintain a mild boil/simmer with the temperature around 206 degrees to get my boil-off rate down. My last batch I performed this way I went from 2.1 Gal./Hr. to 1.1 Gal./Hr.