Afternoon all.
It looks like I'll have to reduce my brew length down to 10-12 litres, don't ask, my pot is a 38 litre about 37cm in diameter.
I'm worried that it's too big for small batches, that the evaporation will be simply too much.
Should I look out for a pot of say 20 litre that I could use on the stove top?
Thanks for your advice.
Atb. Aamcle
Sent from my Nexus 7 using Tapatalk 2
Post #2 made 11 years ago
I have a 10 G kettle with all the bells and whistles.. i'm not unhappy that I bought it.. but, it is way too large for 3G batches.. not from the standpoint of evaporation. My evaporation rate was the same for a 5G in the kettle as it was for a 3G boil. My problem was trying to maintain my temperature during the mashing. There is not enough mass IN the pot for the size of the pot. I will try to experiment a bit on the next batch.. but, I think it will be fruitless. I'll have to remove the pot from the burner and place it in an insulated bag (sleeping bag) I may even have to resort to putting some of that reflective stuff that you put in your car windows while parked.. is it called Reflectex or something like that. IOW, cut a circle the size of the ID of the pot and settle it on top of the mash.
I've only done one batch in it, so there is some experimentation to be done. Firing under the kettle didn't work too well because most of the heat was trapped below the bag. I'd hate to go to a recirculating system using an electric heater but.. who knows. Northern Brewer, up near where Bob lives, has come out with some new tall kettles that look beautiful.. but, the smallest is, as I recall, 8 G. Not much difference. I'd LOVE to find a nice triclad SS pot that is 5G size.. like the Tall Boy's that NB will be selling.
I've only done one batch in it, so there is some experimentation to be done. Firing under the kettle didn't work too well because most of the heat was trapped below the bag. I'd hate to go to a recirculating system using an electric heater but.. who knows. Northern Brewer, up near where Bob lives, has come out with some new tall kettles that look beautiful.. but, the smallest is, as I recall, 8 G. Not much difference. I'd LOVE to find a nice triclad SS pot that is 5G size.. like the Tall Boy's that NB will be selling.
Bill
Hop Song Brewing-Santa Rosa, California
Hop Song Brewing-Santa Rosa, California
Post #3 made 11 years ago
Good Day, IMHO, I would recommend, from my experience, using BIAB, A kettle Twice the Volume of the Batch you want to make is perfect for ALL gravity beers.
So 11-12L batch should be 22-24L Kettle, and 23L Should be 45-50L, and you can make some 1.085OG beer.
So 11-12L batch should be 22-24L Kettle, and 23L Should be 45-50L, and you can make some 1.085OG beer.
Honest Officer, I swear to Drunk, I am Not God.
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Post #4 made 11 years ago
There must have been a lot of requests for pots that have a larger height to diameter ratio.. else Northern Brewer would not have started having them made. I called them today to put in my 2 cents (US) about a 5-6 G pot with the same H/W ratios. I think if enough folks did that.. there would be a message. The pots, AIR, are triple clad bottoms and quite reasonable for the 8G size.. but, still too large unless I started brewing 3.5-4 G and at present.. That's too much beer for me of one type at one time.
Bill
Hop Song Brewing-Santa Rosa, California
Hop Song Brewing-Santa Rosa, California
Post #5 made 11 years ago
I've never considered doing this.. but have, at times, put the lid on about halfway to catch some of the water vapor and drop back into kettle. However, since one needs a decent rolling boil to carry DMS off for over an hour, how do you think this bowl will affect the release of it? The bowl will certainly reduce the surface area of the water, and maybe even have some cooling effect on the steam release, possibly affecting DMS release. Inquiring minds want to know.. I'd guess I'd consider it worth a try
Bill
Hop Song Brewing-Santa Rosa, California
Hop Song Brewing-Santa Rosa, California
Post #6 made 11 years ago
I’ve been thinking about this Bill in terms of physics and chemistry. Two subjects that I used to love, because they explain everything that goes on around you in the world, and it seems they even explain beer, the centre of the universe.
I thought there probably wouldn’t be a readymade answer to your question, so I thought I would try to work out an answer for you.
A larger surface area leads to higher evaporation rate. This is because there are more surface molecules that are able to escape. But other things affect evaporation:
1. Temperature of the liquid, since when hotter, water molecules have higher kinetic energy (they jiggle around more), and can escape more easily from the liquid.
2. Concentration of water vapour in the air above the surface: Putting a lid on a pot of water increases this and the water heats faster because less energy is lost in the evaporation process.
3. Flow rate of air over the surface
4. Atmospheric pressure: the higher the pressure, the less easily water molecules can escape from the water to gaseous form.
Here’s the thing though. All of these things are fine when the water is heating up, and they all apply, but once you reach boiling point, and the boil is on, things change.
Once at the boil, the heat that is applied to the bottom of the pot continues at the same rate and is no longer being employed to increase the temperature of the water, since at atmospheric pressure, the water will go no higher than 100C and that energy has to go somewhere, it really does! It’s "the laws of physics"
Increasing the pressure will allow the heat to continue being employed in raising the temperature to a new higher boiling point, as in a pressure cooker.
Placing a floating bowel on the surface of the boiling wort, may well decrease evaporation, but it will not do so by increasing pressure as there is no seal. It reduces the surface area, but that should not make a difference when the water is actually boiling.
What a floating bowel will do, is dissipate heat to the air above. It will take heat from the liquid and radiate and convect heat away from the boiling liquid, and consequently there will be less heat to cause evaporation. A setup that provided airflow inside such a bowel, would facilitate dissipation of heat by convection.
I believe that it isn’t the surface area per se that affects the evaporation loss in your pot, once the wort has reached boiling point, but rather, it is the surface area of the sides of the pot. A tall low diameter pot, has a lot of steel on the sides (in proportion to the volume of liquid in the pot) to dissipate heat, and consequently less heat is employed in evaporation. The liquid in such a pot has a small surface area and there will be less evaporation while the pot is heating up, and the pot will heat up faster as a result. Once the water has reached its maximum temperature of 100c and can go no higher, then all of the heat energy applied to the pot, that can’t escape from the sides of the pot, will be employed in evaporation. Conversely a shallow, wide diameter pot, will have proportionately less surface area of steel to dissipate heat and more energy will be available for evaporation.
By floating a bowel on the surface of the water, you are in effect adding to sides of the pot and allowing more heat to dissipate through convection and conduction, and thus there will be less heat energy to cause evaporation.
The effect is thus to dissipate more heat, so that less is used in evaporation and less evaporation occurs. But hold on! Why not simply turn down the heat and save yourself the trouble!
The answer is that you are wanting to “boil off” and dissipate dimethyl sulphide (CH3) 2S, which is a water-insoluble inflammable liquid that boils at 37C. It is highly volatile. Every bubble of steam will carry with it some DMS, and the longer the boil, and the more vigorous the boil, the more DMS will be removed.
I would like to propose that DMS removal might be proportional to evaporation loss during the boil. If that is true, then simply either employ a shorter boil time, or turn the heat down. By doing either of those two things you will achieve a “normal” evaporation loss together with a “normal” DMS removal.
I hope that might help.
Ps. Since DMS is escaping with the steam and a floating bowel is hot and wouldn’t cause condensation to occur, the bowel should not impede DMS loss.
I thought there probably wouldn’t be a readymade answer to your question, so I thought I would try to work out an answer for you.
A larger surface area leads to higher evaporation rate. This is because there are more surface molecules that are able to escape. But other things affect evaporation:
1. Temperature of the liquid, since when hotter, water molecules have higher kinetic energy (they jiggle around more), and can escape more easily from the liquid.
2. Concentration of water vapour in the air above the surface: Putting a lid on a pot of water increases this and the water heats faster because less energy is lost in the evaporation process.
3. Flow rate of air over the surface
4. Atmospheric pressure: the higher the pressure, the less easily water molecules can escape from the water to gaseous form.
Here’s the thing though. All of these things are fine when the water is heating up, and they all apply, but once you reach boiling point, and the boil is on, things change.
Once at the boil, the heat that is applied to the bottom of the pot continues at the same rate and is no longer being employed to increase the temperature of the water, since at atmospheric pressure, the water will go no higher than 100C and that energy has to go somewhere, it really does! It’s "the laws of physics"
Increasing the pressure will allow the heat to continue being employed in raising the temperature to a new higher boiling point, as in a pressure cooker.
Placing a floating bowel on the surface of the boiling wort, may well decrease evaporation, but it will not do so by increasing pressure as there is no seal. It reduces the surface area, but that should not make a difference when the water is actually boiling.
What a floating bowel will do, is dissipate heat to the air above. It will take heat from the liquid and radiate and convect heat away from the boiling liquid, and consequently there will be less heat to cause evaporation. A setup that provided airflow inside such a bowel, would facilitate dissipation of heat by convection.
I believe that it isn’t the surface area per se that affects the evaporation loss in your pot, once the wort has reached boiling point, but rather, it is the surface area of the sides of the pot. A tall low diameter pot, has a lot of steel on the sides (in proportion to the volume of liquid in the pot) to dissipate heat, and consequently less heat is employed in evaporation. The liquid in such a pot has a small surface area and there will be less evaporation while the pot is heating up, and the pot will heat up faster as a result. Once the water has reached its maximum temperature of 100c and can go no higher, then all of the heat energy applied to the pot, that can’t escape from the sides of the pot, will be employed in evaporation. Conversely a shallow, wide diameter pot, will have proportionately less surface area of steel to dissipate heat and more energy will be available for evaporation.
By floating a bowel on the surface of the water, you are in effect adding to sides of the pot and allowing more heat to dissipate through convection and conduction, and thus there will be less heat energy to cause evaporation.
The effect is thus to dissipate more heat, so that less is used in evaporation and less evaporation occurs. But hold on! Why not simply turn down the heat and save yourself the trouble!
The answer is that you are wanting to “boil off” and dissipate dimethyl sulphide (CH3) 2S, which is a water-insoluble inflammable liquid that boils at 37C. It is highly volatile. Every bubble of steam will carry with it some DMS, and the longer the boil, and the more vigorous the boil, the more DMS will be removed.
I would like to propose that DMS removal might be proportional to evaporation loss during the boil. If that is true, then simply either employ a shorter boil time, or turn the heat down. By doing either of those two things you will achieve a “normal” evaporation loss together with a “normal” DMS removal.
I hope that might help.
Ps. Since DMS is escaping with the steam and a floating bowel is hot and wouldn’t cause condensation to occur, the bowel should not impede DMS loss.
Last edited by GuingesRock on 16 Mar 2013, 17:21, edited 3 times in total.
Guinges
Post #7 made 11 years ago
GR, Please think about Chemisty and Physics.
Water BOILs at 100C, DMS boils at 37C and will recover Below 37C.
Why do you think you need to have steam to carry away the DMS?
Water BOILs at 100C, DMS boils at 37C and will recover Below 37C.
Why do you think you need to have steam to carry away the DMS?
Honest Officer, I swear to Drunk, I am Not God.
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- SVA Brewer With Over 100 Brews From United States of America
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Post #8 made 11 years ago
Joshua, in a pot on its own DMS would boil at 37c, but in water things change. It is insoluble, so isn’t in solution.
DMS is volatile. So I’m guessing the “bubbles of steam” in the boiling water provide a massive surface area for the DMS to escape the liquid, and it is then carried away into the atmosphere with the steam.
DMS is volatile. So I’m guessing the “bubbles of steam” in the boiling water provide a massive surface area for the DMS to escape the liquid, and it is then carried away into the atmosphere with the steam.
Last edited by GuingesRock on 16 Mar 2013, 18:12, edited 1 time in total.
Guinges
Post #9 made 11 years ago
Great post GR . I'm going to enjoy reading that one a few times.
Bil mentioned above partially covering the kettle with a lid. This doesn't seem to reduce the evaporation rate by much at all unless you have the lid placed so all the condensation drips back in. I think doing this is probably not a good idea but maybe I am wrong on this. Maybe the stuff that drips back in is purified?
The only other thing I wanted to mention is that the boil has many other purposes besides driving off DMS. Some of these are time-dependent (eg coagulation of proteins) and unrelated to evaporation so a reduced boil time is probably not the best idea. I think 60 minutes minimum is the lowest anyone should go.
Good stuff!
PP
Bil mentioned above partially covering the kettle with a lid. This doesn't seem to reduce the evaporation rate by much at all unless you have the lid placed so all the condensation drips back in. I think doing this is probably not a good idea but maybe I am wrong on this. Maybe the stuff that drips back in is purified?
The only other thing I wanted to mention is that the boil has many other purposes besides driving off DMS. Some of these are time-dependent (eg coagulation of proteins) and unrelated to evaporation so a reduced boil time is probably not the best idea. I think 60 minutes minimum is the lowest anyone should go.
Good stuff!
PP
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Post #10 made 11 years ago
On balance I think just I'll look out for a smaller pot, l'll store my existing one in case of need :-)
Many Thanks to you all.
Aamcle
Many Thanks to you all.
Aamcle
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- Over 20 Brews From Great Britain
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Post #12 made 11 years ago
GR, A tall Pot with a very low level of wort is like a Distiller System, The top is at Ambient temps, the Bottom is at 37C or 100C.
If there is not a way to pull the DMS out of the Kettle, It will stay IN the kettle until there is a BIG boil to push it out.
The BIG BREWERYS have a low vacuum system to remove the DMS and Increase evaporation. This allow a better Hop Utilization (more hops/less time), And less brewing Time (more wort/hour).
Try some experiments.......
If there is not a way to pull the DMS out of the Kettle, It will stay IN the kettle until there is a BIG boil to push it out.
The BIG BREWERYS have a low vacuum system to remove the DMS and Increase evaporation. This allow a better Hop Utilization (more hops/less time), And less brewing Time (more wort/hour).
Try some experiments.......
Honest Officer, I swear to Drunk, I am Not God.
-
- SVA Brewer With Over 100 Brews From United States of America
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Post #13 made 11 years ago
Wow, this is great. GR, you did a great job of bringing this down to my level.. not a ton of physics lingo. Never was much on that.. rather the marine biological sci's.
Yeh, I've seen some videos where brewmasters talked about a rolling boil. (they do small batches to test recipes, etc) And they talked about a vigorous boil as mentioned. It doesn't have to be a huge rolling boil.. but more than simmer. Also, as PP mentioned, it the boil does more than drive off DMS. It has a lot to do with drawing out the goodness in the hops as well.
Regarding pot size. People make great beer in turkey fryer pots.. as well as the newer pots made by Bayou Classic that are ss with tri clad bottoms. They also make great beer with pots that have a lot of surface area with more conventional 'soup' pots. I just plain love the looks of the tall pots.. maybe because I got my start using turkey fryers and simply felt, no science, that they worked better.
I doubt there will eve be built a pot to my liking.. so, I'll have to to a workaround for my small batches. My major concern is not with the boil ( as I can adjust for that).. rather in maintaining heat during the mash. As discussed in other threads, I can (A) Ignore the issue as it seems most of the conversion takes place in the first five or so minutes, or (B) I can remove the pot from the burner and wrap the pot in a good insulating material and prolong the heat retention, or (C) I can add an insulated "blanket" to the top of the wort itself, or (D) I can do all three.
Thanks again for a great discussion. SO different from some of the terse answers I see on other forums that are not at all helpful.
Yeh, I've seen some videos where brewmasters talked about a rolling boil. (they do small batches to test recipes, etc) And they talked about a vigorous boil as mentioned. It doesn't have to be a huge rolling boil.. but more than simmer. Also, as PP mentioned, it the boil does more than drive off DMS. It has a lot to do with drawing out the goodness in the hops as well.
Regarding pot size. People make great beer in turkey fryer pots.. as well as the newer pots made by Bayou Classic that are ss with tri clad bottoms. They also make great beer with pots that have a lot of surface area with more conventional 'soup' pots. I just plain love the looks of the tall pots.. maybe because I got my start using turkey fryers and simply felt, no science, that they worked better.
I doubt there will eve be built a pot to my liking.. so, I'll have to to a workaround for my small batches. My major concern is not with the boil ( as I can adjust for that).. rather in maintaining heat during the mash. As discussed in other threads, I can (A) Ignore the issue as it seems most of the conversion takes place in the first five or so minutes, or (B) I can remove the pot from the burner and wrap the pot in a good insulating material and prolong the heat retention, or (C) I can add an insulated "blanket" to the top of the wort itself, or (D) I can do all three.
Thanks again for a great discussion. SO different from some of the terse answers I see on other forums that are not at all helpful.
Bill
Hop Song Brewing-Santa Rosa, California
Hop Song Brewing-Santa Rosa, California
Post #14 made 11 years ago
Thanks Guys! Only took me three hours to figure out what I wanted to say and write it.
Now I appreciate how much time and effort goes into some of PP’s posts.
Was fun though.
ps. Bill, try option A or experiment and see how A,B, and C compare and report back plse.
Now I appreciate how much time and effort goes into some of PP’s posts.
Was fun though.
ps. Bill, try option A or experiment and see how A,B, and C compare and report back plse.
Guinges
Post #15 made 11 years ago
I know having a "pot too big" shouldn't warrant a discussion about DMS; however, i thought i should add some comments too.
There are a number of beers & styles that are produced without a wort boil at all, and these do not suffer from DMS problems. The reason for this is that DMS is not just sat in your wort waiting to be boiled off. if it were, it would be evaporating with temps above 37C (if not covered).
It is S-methionine that is sat in your wort, and that is the DMS "precursor".
Once you hit about 85C, SMM is converted to DMS, & then it needs to be removed by boiling.
Basically, the longer you boil, the higher the percentage of SMM removal occurs, and hence DMS (if uncovered).
There are a number of beers & styles that are produced without a wort boil at all, and these do not suffer from DMS problems. The reason for this is that DMS is not just sat in your wort waiting to be boiled off. if it were, it would be evaporating with temps above 37C (if not covered).
It is S-methionine that is sat in your wort, and that is the DMS "precursor".
Once you hit about 85C, SMM is converted to DMS, & then it needs to be removed by boiling.
Basically, the longer you boil, the higher the percentage of SMM removal occurs, and hence DMS (if uncovered).
G B
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
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- SVA Brewer With Over 100 Brews From Great Britain
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Post #16 made 11 years ago
Mally, Perfect!....The plot thickens.
I read about that before, but it obviously didn’t sink in.
When you say a number of beer styles are produced without a boil. I didn’t know about that. What are the beer styles please? I’d like to look them up.
Now I’m really wondering You can mash and FWH at temperatures well under 85C, so why the heck go above that temperature and start creating DMS and then have to boil for an hour to get rid of it. Seems like shooting yourself in the foot to me.
There might be isomerization of alpha acid benefits to boiling, but is it really worth it? I wonder if FWH might do the trick nicely without boiling. Until recently I’ve been making beer that I really like, with 10 minute additions only.
One other benefit of boiling is sanitisation, but pasteurisation (normally done at 70 °C (158 °F)) might be enough, since it will be around that temp for 2 hours, with a 90 min mash and a 30 minute FWH steeping.
I read about that before, but it obviously didn’t sink in.
When you say a number of beer styles are produced without a boil. I didn’t know about that. What are the beer styles please? I’d like to look them up.
Now I’m really wondering You can mash and FWH at temperatures well under 85C, so why the heck go above that temperature and start creating DMS and then have to boil for an hour to get rid of it. Seems like shooting yourself in the foot to me.
There might be isomerization of alpha acid benefits to boiling, but is it really worth it? I wonder if FWH might do the trick nicely without boiling. Until recently I’ve been making beer that I really like, with 10 minute additions only.
One other benefit of boiling is sanitisation, but pasteurisation (normally done at 70 °C (158 °F)) might be enough, since it will be around that temp for 2 hours, with a 90 min mash and a 30 minute FWH steeping.
Last edited by GuingesRock on 18 Mar 2013, 17:44, edited 2 times in total.
Guinges
Post #17 made 11 years ago
Berliner Weisse is probably the best known style of no boil, probably some lambics, but i learned a lot from Chad Yakobsons podcast on the brewing network (crooked stave), all his beers are brewed with Brettanomyces yeast, and he produced some fantastic beers without boiling (pure guava petite sour).
However, i don't think no boiling is an option for all beer styles. As PP mentioned above, the boil helps remove proteins (hot break).
i couldn't imagine trying a pilsner without a boil but then again I have never tried so...
However, i don't think no boiling is an option for all beer styles. As PP mentioned above, the boil helps remove proteins (hot break).
i couldn't imagine trying a pilsner without a boil but then again I have never tried so...
G B
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
-
- SVA Brewer With Over 100 Brews From Great Britain
-
Post #18 made 11 years ago
BIAB, No-Boil, No-chill,...How cool would that be
Mash the stuff, FWH and ferment.
Worth investigating
Mash the stuff, FWH and ferment.
Worth investigating
Guinges