Just recorded how much gas used when brewing with SaazWillamette on Wednesday so thought I'd pass on some notes....
Firstly, a four ring burner, from memory, is too wide in diameter for most kettles. A typical 50L kettle will be 40 cm in diameter. I generally do two side by side "double" batches on a brew day and therefore have two 70L kettles (45cm diameter). I have one three-ring burner with a stand, one 'Italian' burner and use adjustable regulators for both (that is important). Pics of all these are attached [EDIT: crap pic of the three-ring burner stand but am out of time.]
Three-Ring Burner - Important!
- Sitting the kettle straight on the burner is inefficient. Buy one with a stand or make one so as the kettle base sits maybe 7cm or so above the burner nipples.
- A new burner often comes painted. Before you brew, fire the burner up to burn the paint off. Do it outdoors as the paint turns into whisps off fine filaments which go everywhere.
- After one or two brews (maybe more?), you might notice a decrease in performance. To fix this, use a small drill bit to clean all the burner holes. I only had to do this the once and have had no further problems in ten years.
Both burners work well. The Italian is slightly quicker to raise temperature but only by a small amount. Here's some numbers from Wednesday where we did two brews that were approx 1.5 times our
standard batch size. To be more specific, we did two batches that aimed to give us about 32L (8.5 Gal) Volume into Fermenter. Both brews used the same mash regime which involved rests at 40, 50, 60, 70 and 76 °C.
Brew A: 1.053 OG / Total Water Needed (TWN) = 52L / 13.7 Gal - Three Ring Burner
Brew B: 1.070 OG / Total Water Needed (TWN) = 54L / 14.2 Gal - Italian Burner
Basically, both burners heated this volume at 1°C per minute BUT SEE 'MOMENTUM' BELOW
Both brews used 3kg of LPG.
I've never written this before (or read it anywhere) but there is definitely a factor in heating which I'll call 'momentum' for now.What do I mean by this?
What I'm saying is that saying something like, "temperature increased at the rate of 1°C per minute," might be true for a single small step but, is totally misleading for a large step. For example...
The other day, our initial water temperature was 21°C. 1°C per minute implies that our flame would need to be on for about 80 minutes before the boil began. And, that's not far off... It took 13 min of flame on to reach 40°C (Brew A was 14 min and Brew B was 12 min) and then about 10 mins for each step up to mash-out and then about 20 minutes from mash-out to boil.
But, what if we had done a single infusion mash at 65°C and no step at mash-out? We would have only needed the flame on for about 50 minutes on this size batch - about 25 minutes to the mash in at 65 and about the same from 65 to boiling. So why the 30 minute difference?
Every time we turn our flame off, such as when stopping for a mash rest, even though the temperature of our sweet liquor may stay constant, heat energy is still being lost. In fact, a lot of heat energy will be lost before the sweet liquor temperature drops - the burner, stand, kettle bottom and wall temps will drop first. This is why, you may notice, especially with 'heavy' equipment, that your sweet liquor temperature doesn't seem to change for a while after you turn the flame on. Then when it does start to rise, it changes relatively quickly. (You also may have noticed that on such set-ups, if you turn the flame off at the desired temperature, the temperature 'miraculously' continues to rise a few degrees
. This is because the burner, stand and kettle base are still super-hot and that energy is not only dissipating into the surrounding air but also into your sweet liquor.)
Every time you "take a rest" from heating, you are losing the heat energy previously built up in the burner, stand, kettle base and walls. In other words, every rest means that they will need re-heating.
Other Stuff while I Think of It..
- A "double" batch does not take twice as long to heat up than a "single" batch. (It does take longer but not double the time.)
- A "double" batch does not take twice as much gas to maintain the boil. (Same as a half-full versus full saucepan on your stove.)
There I go again... thought I'd just write a quick answer but, as usual, I end up writing an essay
Anyway, hope it is of some use stroup
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