evaporation rate

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allgrainpa

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It appears that my evaporation rate is near the 20-25% after a 60 minute boil. The obvious answer appears to be to add a lid during the boil to decrease the amount of water im losing during my boil but i consistently read that you dont need a lid on during the boiling process. I maintain a nice rolling boil but by no means is it excessive. How do I minimize the amount of wort im losing during the boiling process if not be the use of a lid? What are the advantages/disadvantages of using a lid during the boil?

thank you in advance
 
Don't cover the boil. Lots of stuff happening. I will let someone smarter than I am respond to this. But I believe it is a dms issue.

If you end up with too little wort after the boil you can top up with boiled and cooled water to the volume you need. Or just anticipate and use more water at the start of the boil.

Once you have your system dialed in you can anticipate boil off rates and get your volumes down. Good luck!
 
Dms issue?

Also if i add water after the boil this will effect my OG and cause me to undershoot/overshoot my attended gravity. For example a recent AG brew with very heavy boiling lead to a large amount of evaporation leaving me with only 3 gallons instead of the intended 5. I added the needed 2 gallons of water after the boil giving me a total of 5 galons but my OG was much lower than what I wanted. Thus by adding water this will effect my OG and effect the outcome of my targeted recipe, correct?
 
Dms issue?

Also if i add water after the boil this will effect my OG and cause me to undershoot/overshoot my attended gravity. For example a recent AG brew with very heavy boiling lead to a large amount of evaporation leaving me with only 3 gallons instead of the intended 5. I added the needed 2 gallons of water after the boil giving me a total of 5 galons but my OG was much lower than what I wanted. Thus by adding water this will effect my OG and effect the outcome of my targeted recipe, correct?

No, the amount of sugar in the kettle won't change.

In other words:
1) starting at 7 -> boiling to 3 -> filling to 5
2) starting at 7 -> boiling to 5
...will give you identical gravities in the end.
 
As MalFet said above and high boil off off is your friend, you can oversparge, get better extraction and then boiloff extra water, its very useful for high gravity beers where efficiency goes down
 
please excuse my ignorance but im trying to wrap my head around this.

My understanding is if I have a fixed amount of sugar and I place that amount in 2 gallons of water it would be much more concentrated than if i placed the same amount of sugar in 10 gallons of water. Not sure how gravity and concentration equate out but it seems this would have a direct result in my OG. In other words the OG is a reading of the amount of sugar i have in my wort and if I have same amount of sugar in 2 gallons versus 10 then my OG would differ between quantities of liquid.

if it is that easy to get 5 gallons of water then why so much trouble trying to calculate how much preboil water is needed to end up with desired end product. We could all just make a "concentrate" and just add water to end up with the 5, 10, etc amount of wort
 
let me ask this if i add the needed water to get a total of 5 gallons does it matter when i add the water. can i add it after wort has been cooled just prior to pitching or is it better to add just prior to completion of the boil?
 
Well, most of us start out with much more wort than we need anyway because of the amount it takes to mash and sparge. That may not be the best wording but maybe you can understand. For a 5 gallon batch, I end up with 7-8 gallons of wort after sparging is complete. So it works out great that I'm going to boil off 2-3 gallons. I don't usually end up with "exactly" 5 gallons either. So it's 4.9, or a little over 5, I don't freak out about it but some guys are very particular about being at a certain OG, for me when the boil is over it is what it is until the yeast take over.

One big reason why full volume boils are encouraged over partial volume boils, (which a lot of extract brewers do), is because it can greatly improve head retention and probably a lot of other things I don't know about.
 
You have a lot of questions here....I'll try to answer a few

If you boil off, you are losing water only, no sugars. So whether you start with 10 gallons and boil off 5 or start with 5.5 and boil off .5 it is the same amount of sugars. That's what Malfet was saying as well. Yes, it is more concentrated and hence has a higher OG, but you were asking about boil off, not OG.

The hop utilization rate is different when you boil different amount of liquid. That's why you need to know how much you will lose and not just top off.

If you want to just use water at the end and basically do a partial boil, that is fine, but you do need to boil the water for sterilization instead of just dumping from the faucet. 10 minutes will do the trick - but again your hop utilization will be different.

Boil off is a matter of RH more than anything else if your boil is the good. What's is the temp you are brewing at? Is it super cold?

I suggest figuring this boil rate out. I really think your figures are off - you can't be the only one who brews ad gets 25% rate boil off. You are going down a level (IMO) by adding just water to the end.
 
let me ask this if i add the needed water to get a total of 5 gallons does it matter when i add the water. can i add it after wort has been cooled just prior to pitching or is it better to add just prior to completion of the boil?

Ideally, you don't want to be adding much water at all. Your boiloff rate is very high, and it would be worth figuring out why that is. In any case, if it is going to be consistently that large, you should simply adjust your preboil volume to accommodate. In other words, if you're boiling off two gallons over an hour, you should plan to start with 7 gallons so you end up with 5.
 
I had a 10 gallon megapot and that boiled off 2 gallons per hour which is in the 20% range ...... i would simply make my preboil volume 2 gallons greater than my ending batch size as calculated in beersmith.

I have a keggle and that boils off 1.5 gals per hour. Again, simply adjust preboil volume so that you end up with the appropriate post boil volume.

I think that its the pot dimensions more than anything that determines boil off. Wider mouth pots boil off more.

No need to use a lid. Just plan for it and after a few batches u will be nailing the post boil volumes. Also ditch the "boil off %" mentality and think of it in gallons per hour.

5 gallon or ten gallon batch my gallons per hour boiled off are the same.......
 
I had a 10 gallon megapot and that boiled off 2 gallons per hour which is in the 20% range ...... i would simply make my preboil volume 2 gallons greater than my ending batch size as calculated in beersmith.

^ Same here. I have to boil 8 gallons for a 5g batch. 2 gal boil off then approximately .5 g left in the pot, and .5g trub loss.

Btw, your beer will taste better if you do a full boil rather than adding in the water at the end.
 
Kayos:

To answer your question. I dont have a themometer on keggle (as of yet). I do keep a vigourous boil and typical boil for 60minutes. My preboil OG was 1.042 and according to brewsmith it should have been 1.049. I almost hit my target after boil OG at 1.052 the target 1.053.

I bottled the beer (trying to make sierra nevada PA) and it seemed a little weak from the standpoint of bitterness and aroma.

Let me ask: I batch sparge and typically get 1.5-2 gallons on my inital sparge and then try to put enough water in to get 6.5 gallons. I realize i need to get more preboil wort from my mash. Can you over batch sparge? Im reading by leaving sweet wort behind in MT this could effect my hop utilization which i feel may be the cause of my low bitterness and aroma. Do you agree and what is everyone suggestions?

Thanks again for all the help
 
Kayos:

To answer your question. I dont have a themometer on keggle (as of yet). I do keep a vigourous boil and typical boil for 60minutes. My preboil OG was 1.042 and according to brewsmith it should have been 1.049. I almost hit my target after boil OG at 1.052 the target 1.053.

I bottled the beer (trying to make sierra nevada PA) and it seemed a little weak from the standpoint of bitterness and aroma.

Let me ask: I batch sparge and typically get 1.5-2 gallons on my inital sparge and then try to put enough water in to get 6.5 gallons. I realize i need to get more preboil wort from my mash. Can you over batch sparge? Im reading by leaving sweet wort behind in MT this could effect my hop utilization which i feel may be the cause of my low bitterness and aroma. Do you agree and what is everyone suggestions?

Thanks again for all the help

You don't need a thermometer for boiling.
Pretty much all recipes call for 60 minute boil, unless otherwise specified. Always boil for the entire length of time, and add hops additions as specified.
The boil is a function of reducing the wort (a known value) and hops isomerization.
"Original gravity" refers to the specific gravity just before pitching yeast.
"Starting gravity" is the specific gravity pre-boil.
Beersmith will figure your efficiency if you enter the numbers. It calculates it by how much pre-boil volume you collected, and what the SG gravity was. This is your "Mash house efficiency".
It will also calculate "brew house efficiency" when you enter the post-boil volume and OG.
 
Kayos:

To answer your question. I dont have a themometer on keggle (as of yet). I do keep a vigourous boil and typical boil for 60minutes. My preboil OG was 1.042 and according to brewsmith it should have been 1.049. I almost hit my target after boil OG at 1.052 the target 1.053.

I bottled the beer (trying to make sierra nevada PA) and it seemed a little weak from the standpoint of bitterness and aroma.

Let me ask: I batch sparge and typically get 1.5-2 gallons on my inital sparge and then try to put enough water in to get 6.5 gallons. I realize i need to get more preboil wort from my mash. Can you over batch sparge? Im reading by leaving sweet wort behind in MT this could effect my hop utilization which i feel may be the cause of my low bitterness and aroma. Do you agree and what is everyone suggestions?

Thanks again for all the help

You need to manipulate your Beersmith numbers. Try telling beersmith you want to make a 6g batch instead of a 5g. Aim for a high pre boil gravity and batch sparge with that beersmith tells you to. Yes, you can over batch sparge, you don't want your grain pH to get too high. If you don't have a meter, just taste it and when it stops tasting very sweet, it's time to just use water for the rest of it. If you are leaving some of your first runnings behind, it will make your numbers pretty far off. Get a dip tube or at least have the braid feed off the bottom of your MLT to get the wort, not the top. A 7 point difference is a pretty big deal pre boil. But that does not affect your hops so much - if anything it will taste more hoppy/bitter.


What's your main concern - to get a better taste at the end or your boil off rate?
 
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