How to Prevent Scorching When Distilling on the Grain
- After mulling over new still designs, several options include an emersion heating element. What I'm concerned about is when distilling on the grain or fruit brandy with these elements they will get so hot they will burn the larger particles, ruining the batch.
I have an idea of how to prevent scorching, tell me what you think. I'm considering wrapping the element with heat proof fabric. The hope is that the liquid will filter through the fabric and heat while the large particles never touch the element directly thus preventing burning. I'm sure I would have to find a fabric that will not impart any flavors, but it seems like this should work.
Can any of the big brains in this group offer advice, commentary, or perhaps a better solution?
When designing something, sometimes you can get too involved and hung up on what seem to you to be important details. But in actual fact all you really need to do is step back and look at it from a different perspective. An electric heating element / high pressure steam pipe or whatever very hot heating source only becomes a problem when they get very hot and come into contact with solids in your mash.
Your idea of wrapping the element with heat proof fabric will have the effect of insulating the element (making it cooler on the outside of it and drastically reducing its efficiency. In essence your idea of letting a reduced amount through to the element slowly is fine. But moving the liquid away from the element below the heat proof fabric when it has been heated, that then becomes a problem because the fabric will heat up as fast and as hot as the element so you are back to square one again. A lot of the lads have come across this problem before and these are just a few of the solutions they have come up with:-
1. Before filling the boiler place a stainless steel wire mesh (fine enough to stop the larger grain/fruit particles getting through) raised a couple of inches off the bottom. With gas burners some of the guys put in marbles which start to rumble and move about on the bottom as the fluid heats up, they say it sounds a bit like rolling thunder, this keeps the particles moving thus keeping them from settling on the bottom and this reduces the chance of scorching
2. You can, of course, be a little more patient with your mash wait another week and let it clear a little more then decant your mash when it has cleared. Or buy a clearing agent at your local home brew store (waiting and letting it clear naturally and then decanting it is the cheapest way). Clear mash rarely causes scorching (it would be good if you could buy "patience" across the counter)
3. If you have an electric emersion heater you can feed it a limited constant wattage (a table top router speed control box will feed a constant specific wattage) which translates into heating your mash slowly at the heat tempurature you want i.e. your element doesn’t get as hot thus eliminating scorching. Don’t be tempted of falling into the trap of trying to use a cheapo standard emersion heater thermostat as this will cycle your element on then off, and on and off. This is not good for consistent successful distilling. It can make your mash surge/puke up into your column; you want ethanol vapour in your column not grain/particles from your mash. You need a constant vapour flow through your column to have a good still. Your heating element is the primary control to achieve this steady flow. As I have often said keep it low and slow. You can add a bit of that patience you bought at the brew store that'll help a lot.
Some of the other guys can tell you of their solutions I’m only starting the ball rolling on this thread,
- when i am stilling on the grain AND using gas i use an aluminum disk about 3/8 thick as a heat diffuser seams to work fine for me ....ben
As Geoff mentioned, the fabric will serve to insulate the element. In addition to affecting the efficiency, it will most likely cause the element to overheat and burn out. If the liquid cannot freely flow over the element, it won't remove the heat and the element will fail. I was trying to do the same thing as you, distill on the grain (more or less). I had strained the big stuff out but still had lots of minute grain solids and yeast in the beer. Within about 30 minutes, both of my elements had burned out, melted through the outer metal sheath. I removed them to find that there was a coating less than 1/16 of an inch thick over the entire element, which was enough to burn it up. The fabric would have similar results I believe.
Initially I tried a number of element combinations to overcome this problem including using lower watt-density elements, running 220 volt elements on 110 volts to lower the watt-density, limiting voltage with a 25 amp variac, etc. After fussing around with it for a while, I concluded that electric elements really only work effectively with cleared washes (and I'm not that patient). Even with my best attempts, I still had baked-on solids on the elements and mediocre performace of the still overall. Shortly after, I started experimenting with double boilers and now use an oil bath setup that I mentioned recently in another post.
Having said that, I'm sure someone has figured out a way to do it with electric, agitator maybe? What size of still are you planning?
--- In Distillers@yahoogroups.com, "ballard_bootlegger" <meriwetherdistilleries@...> wrote:
> After mulling over new still designs, several options include an emersion heating element. What I'm concerned about is when distilling on the grain or fruit brandy with these elements they will get so hot they will burn the larger particles, ruining the batch.
> I have an idea of how to prevent scorching, tell me what you think. I'm considering wrapping the element with heat proof fabric. The hope is that the liquid will filter through the fabric and heat while the large particles never touch the element directly thus preventing burning. I'm sure I would have to find a fabric that will not impart any flavors, but it seems like this should work.
> Can any of the big brains in this group offer advice, commentary, or perhaps a better solution?
> Drink Well.