rico567

Recipes 

If you are starting with a regular 6-6.5 gal wort collection, chances are that losing two gallons in an hour's boil is due toan overly vigorous boil. You will encounter some difference of opinion on this issue, but I concur with those who believe that a good, steady bubbling boil is quite sufficient, with no risk of the "DMS monster".....at least I have certainly never encountered it in four years of brewing. I adjust the gas (I have a Bayou Classic SP-10 burner) until I am just maintaining a steady boil.....I see a vigorous rolling boil as both a waste of propane and and creating the need to add water at the end of the boil.

__________________
“Malt does more than Milton can / To justify God’s ways to man”

-A. E. Housman (1859–1936). A Shropshire Lad , 1896.

raptorvan

Recipes 

2 thing...1. I had a girlfriend in highschool that had an aim s/n rico567...that's crazy. Secondly, i changed pots from a sprocket to a keggle so I'm guessing the wider surface area is also a factor so I'm assuming that if i keep it to a low roll i can keep some from evaporating. I wonder and maybe you can help, does brewing outside in 35 degree weather accelorate the evaporation? Or does it just look like that because of the cold hitting the steam?

rico567

Recipes 

I've not brewed outside in the Winter much......it gets pretty cold around here, and I can brew all the beer I need in the Spring & Fall. However, from what little experience I do have boiling outdoors in the cold, I'd say your assessment is correct. In the cold, water vapor that boils off will condense much closer to the source, thus giving the impression of greater boil-off, when that's actually not the case.

__________________
“Malt does more than Milton can / To justify God’s ways to man”

-A. E. Housman (1859–1936). A Shropshire Lad , 1896.

evwoller

Recipes 

actually it is probable that cold weather slows the boil off slightly. as water vapor is not as soluble in air at the decreased temp it would make it harder to expedite the absorption into the air. Although the temps localized directly above the pot should still be really rather warm so it probably wouldn't make much of a difference. I bet the steam looks super thick due to the cold air temps though

I would be interested to see how much more propane or electricity it takes to boil water when the air temp is near freezing. Living in southern california i would never be able to test this out myself unless I decided to pack up the gear and go mountain brewing.

also considering you are boiling in rather cold conditions I can see where a problem arises, you are probably turning up the gas rather high to deal with the increased thermal loss to air etc. when you get to a boil reduce gas flow wait one minute to approximate if you should reduce it further. to get water to temps in a timely fashion you are probably using 2-3x the amount of energy needed to just boil the water.

this could potentially be solved with math (gallons of volume)(btu's necessary to boil gallon)+(approximation for inefficient heat exchange between burner and pot) would give you a decent number of necessary btu's to keep your pot at a boil. Then you incorporate your burners maximum btu out put and you can get an idea of how much pressure you should let through.