I bought a cheap gas burner that runs on 16 oz propane. I’m making a porter and I can’t get the wort above 207 or so. I’ve got 4 gallons going. Any concerns if I don’t get a full rolling boil going? Thanks.
Are you at about 2,000 feet in elevation? For every 500 feet in elevation the boil point temperature decreases approximately 1°F.
Could also be just not enough BTU’s being produced. The max my kitchen stove brings to a boil in a timely manner is 4 gallons.
About 1200 feet here.
Describe the burner you are using.
Are you talking about those little canisters you use on a camp stove?
Its a Stik tourist grill. I stripped the grill and kettle and am just using base. It works well but doesn’t have the cajones to boil 4 gallons.
Yep, that’s what it is. Not a thermodynamics expert, but I think I don’t have the energy output necessary.
I looked up the reviews for the grill. Seems to be very low BTU even for cooking burgers when there is some breeze. Once in a while NB offers a free burner with an order. You do need more power for a full boil kettle…
Not enough btu from your burner. I think. What you need. Say your water comes out of the faucit at 70 fh. Water about 8.3 lbs per gal. You will need. 8.3×212-70 fh = 1.1786 btu. Example. A 7.7 gall boil. To get 5.5 gall wort. 7.7 gal x 1.1786 = 9.0752 minimum btu for a 60 min boil
Bottom line, you need a much bigger burner.
BTUs and BTUs per hour are often confused, especially since many burners report a BTU rating when they really mean BTUs per hour. A BTU is the amount of energy (heat) needed to raise 1 pound of water 1 degree Fahrenheit. As Wilco points out, it takes 1,178.6 BTUs to raise 1 gallon of water from 70F to boiling (at sea level anyway where water boils at 212F). That’s 5893 BTUs to boil 5.5 gallons of water.
The Dark Star Burner 2.0 claims it is “loaded with 65,000 BTUs of brewing power”. That really means it claims to output 65,000 BTUs per hour.
In theory then, the Dark Star 2.0 will boil 5.5 gal in under 6 minutes (5893 BTUs / 65,000 BTUs/hr * 60 min/hr = 5.43 minutes). Reality is nowhere near that fast, however, because not all of the heat produced by the burner goes into the water, the water is also losing heat, both by boil-off and to the air around the pot, and you don’t often run the burner wide open (at 65,000 btu/hr) because doing so would just waste propane - see BG12 vs BG14 burner
There are a few actual boil times reported here Let's Gather Data: BTU and time to reach Boil