Help 50% boil off rate

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nyer

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I have been struggling with low amounts of wort going into the fermenter. I never get 5 gallons. I use a kettle and turkey fryer burner to boil in and I have always used generic software online to calculate my mash temps. and water amounts. I also left the boil off rate at 10 percent in the formula. I just tried an experiment by boiling 5 gallons of water for 60 minutes. I turned the burner down pretty low and had a good boil. When it was over I only had 2 1/2 gallons left. I don't get it how can I possibly lose 50%? I'm doing an 11 1/2 gallon batch of BM cream of 3 crops tomorrow and I really want to end up with 2 full kegs. I am thinking I'm boiling too hard but the flame was turned down quite a bit.
 
I think you are looking at it the wrong way. 2-2 1/2 gallons is an acceptable boil off rate if you have your burner turner up.You are going to lose the same amount of volume if you boil 10 gallons or 5 gallons. It is not a percentage of the total amount of water you use. The best way would be to calculate your boil off rate in gallons / hour instead of percent. Then adjust your sparge or add top off water at the start of the boil to account for your boil off rate.

Boil 10 gallons of water. Figure out how much is lost to evaporation. Use that number to figure out how much you need to start with to achieve 10 gallons in the kegs. You also need to determine how much you lose to trub, racking and yeast.

For my system, to get 10 gallons in two kegs, I have to start with 15 gallons in my kettle. I boil for 90 mins and, after whirlpool and leaving trub behind in the kettle, I have 5.6 gallons in each fermenter. I do rack to a conditioning vessel so there are losses. When I finally rack to the keg, It is full at 5 gallons.

You need to start at what you want in the keg and calculate backwards what your losses are. Measure what you leave behind at each step and record it. Boil 10 gallons of water a couple of times at different rates of boil so you will KNOW what amount of of water is lost for each setting. Record this. Then you can plan you recipes accurately.
 
Turn the heat down more. Turn it down until it quits boiling and then slowly turn it up until you have a boil. There's no need to boil hard enough to evap half your wort.
 
I think you are looking at it the wrong way. 2-2 1/2 gallons is an acceptable boil off rate if you have your burner turner up.You are going to lose the same amount of volume if you boil 10 gallons or 5 gallons. It is not a percentage of the total amount of water you use. The best way would be to calculate your boil off rate in gallons / hour instead of percent. Then adjust your sparge or add top off water at the start of the boil to account for your boil off rate.

Boil 10 gallons of water. Figure out how much is lost to evaporation. Use that number to figure out how much you need to start with to achieve 10 gallons in the kegs. You also need to determine how much you lose to trub, racking and yeast.

For my system, to get 10 gallons in two kegs, I have to start with 15 gallons in my kettle. I boil for 90 mins and, after whirlpool and leaving trub behind in the kettle, I have 5.6 gallons in each fermenter. I do rack to a conditioning vessel so there are losses. When I finally rack to the keg, It is full at 5 gallons.

You need to start at what you want in the keg and calculate backwards what your losses are. Measure what you leave behind at each step and record it. Boil 10 gallons of water a couple of times at different rates of boil so you will KNOW what amount of of water is lost for each setting. Record this. Then you can plan you recipes accurately.


I just put a better regulator on the burner so I can turn the flame down more. So if understand this a little better if I want 5.5 gallons in my fermenter (only accounting for boil off)and I'm boiling 60 minutes I need to start with approx. 8 gallons?
 
Turn the heat down more. Turn it down until it quits boiling and then slowly turn it up until you have a boil. There's no need to boil hard enough to evap half your wort.


I'm trying that now. I never really understood what a rolling boil was supposed to be. I can boil with a small flame or really boil with a large one. Should there be bubbles or should the water kind of "roll".
 
I just put a better regulator on the burner so I can turn the flame down more. So if understand this a little better if I want 5.5 gallons in my fermenter (only accounting for boil off)and I'm boiling 60 minutes I need to start with approx. 8 gallons?

Maybe. On my system I want 5.25 in the fermenter. When I account for trub losses and boil off I need 6.5 in the kettle pre-boil for a 60 min boil, up that to 7 gal for a 90 min boil.

Your results may vary, depending on your boil off rate and trub losses, etc. You'll have to figure this out with a bit of trial and error.

I'm trying that now. I never really understood what a rolling boil was supposed to be. I can boil with a small flame or really boil with a large one. Should there be bubbles or should the water kind of "roll".

Some people boil the ever loving snot of their wort. I just get it to a boil where there is decent turnover of the liquid. IMO, you don't need the wort exploding out of the kettle. Just make sure it's constantly turning over.

I made a heat shield with some aluminum flashing for my turkey fryer. I added some horizontal support to my fryer legs for the shield to rest on. The shield is flashing riveted together in a cylinder that is slightly larger than my kettle. I can keep a nice rolling boil and can barely here my burner whispering. Best $7 i ever spent. I'm now getting about 8, 5 gal batches per tank of propane.
 
I'm trying that now. I never really understood what a rolling boil was supposed to be. I can boil with a small flame or really boil with a large one. Should there be bubbles or should the water kind of "roll".

I would try to use the lowest amount of heat needed to hit a boil. Break out your thermometer. Check you boil temps. Is is 212 F in your area? You cannot have a hotter temp than boiling in an open container. It doesn't matter if you are having big bubbles or a small roll. The temp is the same. Use the lowest setting that achieves boiling temp for your altitude.

You will save money on Propane and perhaps not evaporate quite as much. It does take a bit of time and trial and error to calibrate your system.
 
I think the new regulator is making a huge difference. I'm at 30 minutes and not much has boiled off. More importantly I'm not getting the deafening roar I used to get. I have the flame down nice and low and can't even hear it. The old regulator sounded like a jet engine inside my open garage. I bet I save a ton of gas too. I hope this works......30 more minutes.
 
I've always heard to boil as hard as possible. I read that it helps the hot break. That said. It's personal preference.

As far as boil off rate, you sound like yours is very normal. I boil off a gallon per half hour. It looks like you boil off 1.25 per half hour. All you gotta do is adjust accordingly for your setup.
 
Yep, if you are doing a 10g batch and want say 10.5g in the fermentor then you need to start with 10.5g+2.5g = 13g in the pot. Also If boiling softer has less boil off and that is what you want to do then just make sure you account for the boil off rate in your pre boil volume.

Will be interested in the results of your boil off experiement with the new regulator. What pot do you have by the way?
 
I've always heard to boil as hard as possible. I read that it helps the hot break. That said. It's personal preference.



I've heard this too, but it doesn't make sense. It's not like we are heating the water any higher than 212, though more energy passes through it. Don't know why or how it would actually affect hot break. Sounds like brewing mythology to me.
 
Yep, if you are doing a 10g batch and want say 10.5g in the fermentor then you need to start with 10.5g+2.5g = 13g in the pot. Also If boiling softer has less boil off and that is what you want to do then just make sure you account for the boil off rate in your pre boil volume.

Will be interested in the results of your boil off experiement with the new regulator. What pot do you have by the way?[/QUOTE


There was a pretty big difference. This time I boiled off a little less than 1.5 gallons. I'm guessing it would be very close to 1.4 gallons. I'm using a converted keg. I'm amazed at the difference the regulator made. I'm hooked up to my house propane and I couldn't get a regulator to hook up because of the fitting for the portable propane tank. I ended up using a hose with a gas valve. It worked pretty good but it wouldn't allow fine tuning and it was REALLY loud. This morning I tried taking the regulator apart and discovered that it could be used. This allows much better adjustment and for some reason it just seems to work better at boiling and it's really quiet.

I'm using this sight for my calculations. Should I just enter 28% in
"the percent boil off per hour" box to get the correct amount now?

http://www.brew365.com/mash_sparge_water_calculator.php
 
I'd use brewtarget. It's free and open source. A guy on here has developed it, and you can enter in your boiloff rate in gal/hr. He also just added a great new mash designer that will allow you to easily hit your numbers.
 
I'd use brewtarget. It's free and open source. A guy on here has developed it, and you can enter in your boiloff rate in gal/hr. He also just added a great new mash designer that will allow you to easily hit your numbers.

I checked brewtarget out, it looks pretty cool but I don't have the time to figure it out by tomorrow morning. I'm going to have to use the brew365 calculator for this one. It's telling me I need 23.42 gallons of water to make an 11.5 gallons batch. My keggle isn't going to work, something must be wrong. I'm thinking I lose 2.1 gallons per 1 1/2 boil. I should need 13.6 gallons then to end up with 11.5 right?
 
There was a pretty big difference. This time I boiled off a little less than 1.5 gallons. I'm guessing it would be very close to 1.4 gallons. I'm using a converted keg. I'm amazed at the difference the regulator made. I'm hooked up to my house propane and I couldn't get a regulator to hook up because of the fitting for the portable propane tank. I ended up using a hose with a gas valve. It worked pretty good but it wouldn't allow fine tuning and it was REALLY loud. This morning I tried taking the regulator apart and discovered that it could be used. This allows much better adjustment and for some reason it just seems to work better at boiling and it's really quiet.

I'm using this sight for my calculations. Should I just enter 28% in
"the percent boil off per hour" box to get the correct amount now?

http://www.brew365.com/mash_sparge_water_calculator.php


You would need to start with how much wort you want in the fermenter. Lets assume 10.5g. Now at your boil off rate you would lose 1.4g of that an hour. So you would want to start with 10.5g+1.4g =11.9g. This would make your boil off % = 1.4g/11.9g*100 = 11.8%.

You have to calculate this on the fly for every batch size first assuming how much you want in the fermenter, then adding the amount you lose over the hour.
 
I checked brewtarget out, it looks pretty cool but I don't have the time to figure it out by tomorrow morning. I'm going to have to use the brew365 calculator for this one. It's telling me I need 23.42 gallons of water to make an 11.5 gallons batch. My keggle isn't going to work, something must be wrong. I'm thinking I lose 2.1 gallons per 1 1/2 boil. I should need 13.6 gallons then to end up with 11.5 right?

It would far overshoot if you entered in 28%, remember that it is 28% cause you started with 5g. If you started with 2.8g it would be 50%. Since you will be starting with far more wort (closer to 13g), 1.4g is a far smaller %.

With those numbers to end up with 11.5g post boil need to enter roughly 2.1/13.6*100*60/90 (adjust for 1.5h instead of 1) = 10.29 boil off %. The amount of water will include the water that it expects you to lose due to grain absorbion.

I entered this in and got around 15g of water for you. But keep in mind it expects a few gallons of this to be lost due to grain absorbsion.
 
It would far overshoot if you entered in 28%, remember that it is 28% cause you started with 5g. If you started with 2.8g it would be 50%. Since you will be starting with far more wort (closer to 13g), 1.4g is a far smaller %.

With those numbers to end up with 11.5g post boil need to enter roughly 2.1/13.6*100*60/90 (adjust for 1.5h instead of 1) = 10.29 boil off %. The amount of water will include the water that it expects you to lose due to grain absorbion.

I entered this in and got around 15g of water for you. But keep in mind it expects a few gallons of this to be lost due to grain absorbsion.

Thank you so much for the help, I got myself so confused I blew all the calculations.
 
i'm confused. why not just top off with extra water if you post boil volume isn't enough? seems like you are making this too hard.
 
I never undertood the % for boil off. Near as I can tell, surface area at a given temp is most important factor. The same pot should(more or less due to heating time) should lose the same amount per hour regardless of starting volume, assuming the boils are the same. I use Beersmith and just ignore the % boil off question. I put in my pre boil volume manually, which was determined by test w/water. Not an exact science, but 5 1/4 gallons or 5 1/2 gallons is good enough for me.
 
i'm confused. why not just top off with extra water if you post boil volume isn't enough? seems like you are making this too hard.

This works too. The calculator is just to get as close as possible. Following your line of thought why not just do half or 1/4th boils and top off? I bet it would work just as well, but I think it is commonly believed that full boils result in better beer (I don't really know the exact science so I won't try to back that with any evidence or claim it as fact). Even if full boils make better beer I agree that just topping up a little will do no harm, I do it all the time.
 
I decided that until I get my electric system built I'm not going to worry so much about boil off. I'm 30 minutes into my mash right now and I'm going to boil lighter like I did during my 2nd experiment. At this point I'll be happy as long as I can fill a keg all the way and my gravity comes out right.
 
I decided that until I get my electric system built I'm not going to worry so much about boil off. I'm 30 minutes into my mash right now and I'm going to boil lighter like I did during my 2nd experiment. At this point I'll be happy as long as I can fill a keg all the way and my gravity comes out right.

Let us know how it goes. Did you use rice hulls? Last time I made cream of 3 crops I had a stuck sparge and it was quite the annoyance. From now on I am going to use rice hulls in everything.
 
This works too. The calculator is just to get as close as possible. Following your line of thought why not just do half or 1/4th boils and top off? I bet it would work just as well, but I think it is commonly believed that full boils result in better beer (I don't really know the exact science so I won't try to back that with any evidence or claim it as fact). Even if full boils make better beer I agree that just topping up a little will do no harm, I do it all the time.

yeah of course aim to hit your final volume, but i just wouldn't worry so much if it is under. i've always heard that full boils are better, too. better hop extraction maybe?

coming in under volume also gives an advantage in wort cooling. i usually throw a 1 gallon jug of water in the freezer before i start brewing and use that to top off. the really cold water helps bring down the temp. or if you don't add cold water, a smaller volume, say 4 gallons instead of 5, probably cools faster because of less thermal mass or something like that.
 
So i may be way to late in this discussion but you also need to be watching your gravity. Boil off isn't just about volume, it's about concentrating the sugars to the point you want them. If you don't watch the gravity and you don't boil enough, you won't get enough ETOH. Also, if you boil longer to compensate for to much water, you will get a higher bitterness level from the continued boil of the hops. Basically if you don't get this correct you will end up with either watery or overly bitter beer.
 
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