I am speculating that gravity may not be required to maintain the recirculation, as the heat differential might do it. There is a design issue of whether it is attempted to push steam or boiling water into the coil. In other words, with one outlet at the top of the boiler keg and another line entering in at the top and terminating just above the bottom, which way does the flow go?
You can use thermosyphoning to do it. The heating coil or boiler should be below the still boiler's water jacket or coil. Connect top to top and bottom to bottom. When you apply heat the water will flow to the top of the still and cool down as it heats the wash and exit at the bottom where it will enter the botton of the heater to be recirculated. You would need to include a vent pipe extending well above the still's boiler to prevent pressure build up. The pipework would need to be at least 1" to get a suitable flow rate.
It's using gravity to work - but only because hot water is less dense than cold.
It would still get painfully slow toward the end of the run to get the last of the tails because the temperature of the wash will be approaching the temperature of the heating water. This could be overcome by putting a weight on the vent pipe to make it act like a pressure cooker when everything slows down too much.
If u run a mash on a water bath you are basically trying to boil water (with traces of alcohols) by heating it with boiling water. That makes it incredibly inefficient because the energy has to be transferred to the boiler through a basically nonexsisting temperature difference. Has anyone considered oil bath instead of water bath? I've used cooking oil bath for heating my small glass potstill's boiler with great success for many times. It's very effective and you can control the temperature precicely. Of course there is a chance of burning the grain in the mash if you overdo with the heat but it's still a whole lot less probable than with having a flame directly under the boiler.
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="rezaxis"
Please take the design and execution of any pressure vessel very seriously.
Use a seperate steam boiler and pass the steam line back through the flame to superheat it. Use large diameter pipe so it runs at atmospheric pressure. You'd possibly need a way of draining any water condensing in the jacket around your still boiler.
Potheads's pneumatic sealed double boiler would be a good candidate for this.
This could be where an electric hot water service comes into its own, ie, as the boiler. Mine has a cold water line-in at the base, a hot water line-out at the top, and a pressure relief valve at the top. Shame 'bout the 1/2" fittings, but presumably not too difficult to replace if desired.
Thinking about it a bit more, any heating coil is probably going to require a facility for dismantling in order to get it in and out of the mash. With compression fittings, that probably rules out steam.
markx wrote:If u run a mash on a water bath you are basically trying to boil water (with traces of alcohols) by heating it with boiling water. That makes it incredibly inefficient because the energy has to be transferred to the boiler through a basically nonexsisting temperature difference.
That is not correct. Energy given into the water bath is taken by the mash independently from temperature diffrence and water boiling point prevent from distilling tails. If you want to distill a little faster, but with tails and without mash burnig just use salt water. It has a 15°C higher boiling piont. It is acceptable time /no burning compromise.
personally i think the mashing false bottom would work wonders to stop the grain from burning or sticking... you just need something to hold the grain off the bottom of the pot
it would save the hassle of a steam jacket etc
Whiskey, the most popular of the cold cures that don't work (Leonard Rossiter)
That is not correct. Energy given into the water bath is taken by the mash independently from temperature diffrence
Thermal energy is not transferred from one body to another without a temperature difference. It can only be transferred from the hotter object to the cooler one (if you don't force the transfer with additional energy, like in a refridgerator or heat pump) Check the basic thermodynamic laws if you don't believe me.
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markx wrote:Thermal energy is not transferred from one body to another without a temperature difference.
I'm agree with that, but heater gives energy to water and water passes on to mash. To vaporize from mash ethanol you need not more than 100 degrees and in water bath the temperature of mash becomes upraised to such temperature.
With the heating element in the wash you have a larger temperature difference and less surface area for the heat transfer to act on.
With a water bath you have a smaller temperature difference but much more surface area. It will be less efficient, but might not be that big of a deal.
="masonjar"
With the heating element in the wash you have a larger temperature difference and less surface area for the heat transfer to act on.
With a water bath you have a smaller temperature difference but much more surface area. It will be less efficient, but might not be that big of a deal.
It only becomes a problem towards the end when the boiling point of the wash approaches 100degC and you're trying to extract the last bit of ethanol. In the early part of the run I have to be careful to not flood the column (reflux still) or get vapour out of the condensor (pot still).
I have thought about using salt water but rejected it because by water jacket is steel (SS boiler inside it) and is kept full with exhaust cooling water.
="theholymackerel". Whiskeys fermented and distilled on the grain are much oilier as Fourway said. I like that aspect of them. But if yer whiskey is TOO oily try chillin' it in the freezer and pourin' it through a stainless funnel with a paper coffee filter and a cottonball in the neck of the funnel.
This point has been running around in the back of my mind for a while now, and I would speculate that it is not so much cooking grain as cooking yeast that is responsible. Why? Well, for starters, grain only contains unsaturated oils, whereas yeast produces saturated fats during fermentation. Saturated material is generally less soluble than unsaturated. Secondly, grain is normally not regarded as having any significant essential oil content, so water dilution of the distillate is unlikely to crash alcohol-soluble oils out of solution. Finally, any grain oil ought to wind up dissolved in the alcohol in the still, and so should distill across cooked grain or no cooked grain (that is, unless the oil is so non-polar as to be alcohol insoluble). It may however be that the heat rupturing the yeast cells is responsible for the effect. A simple test of this idea - strain out the grain, but distill on the sediment.
I don't know about that muchanic I've strained out the grain and run the wash, sediment and all, several times and never got a cloudy product. The only time I got a cloudy product was by distilling on the grain. It came out of the still crystal clear but clouded about 12-24 hours after it was diluted to 40% or so.
This BTW is one of the finest products I've made so far. The cloudiness was filtered out easily by chilling the produc and filtering it through a bit of cotton and a coffee filter.
I plan on distilling on the grain more in the future. But first I'm going to come up with a more efficient method than a double boiler.
Give a man a fish and he will eat for a day. Teach a man to fish and he will sit in a boat all day and drink beer.
I plan on distilling on the grain more in the future. But first I'm going to come up with a more efficient method than a double boiler.
As I recall your reporting of it you had your boiler in a pot of water without a good seal to the boiler. Hard to think of a less efficient system.
As I said previously ' Pothead's' double boiler would be ideal. - Heat the bottom with gas when you're in no danger of burning, heat with hot water through the jacket in the early stages of distilling on the grain and put a small 'pressure cooker' type weight on the jacket outlet when things start to slow down too much.
With the proviso that you've tested the weight and determined that it only increases the temp a few degrees and the water jacket is safe - but I dont really need to tell you that - it's for the inexperienced who are reading.
I agree Horn the system I used was horribly inefficient. But this was the first time I tried distilling on the grain. The next time I do it I'm gonna hang the grain from the mash in a cloth sack right smack in the middle of the boiler and see how that works. I also want to try putting 6 inche or so of clean sand or very small river rock (pebbles) in the bottom of the boiler and then dump the mash in grain and all and strip it.
My problem right now is to find the time. It won't quit snowing here so therefore I can't quit skiing..........life is tough
Give a man a fish and he will eat for a day. Teach a man to fish and he will sit in a boat all day and drink beer.
