Electric Mashtun Leaks...

maztec said:

10 gallon and 5 gallon batches, same kettle.

5500W, ULWD element. Assumed 100% energy transfer efficiency since it is inside the kettle, so that is 18,766 BTUs.

1 BTU raises 1 pound of water by 1 degree Fahrenheit in 1 hour. (Gallons * 8.3lbs/gallon * (Boiling - StartTemp))/BTUs = time to boil.

For 10 gallons starting at 70F to boil it is: (10*8.3*(212-70))/18766 = rounded up 38 minutes to boil.

For 5 gallons starting at 70F to boil it is 19 minutes.


These seem like reasonable times to me. Furthermore, if I install a PID/SSR, I can manage the degree of boiling so it is a nice rolling boil rather than a thunderous turn the pot over boil.

Click to expand...

Yeah, heating time is not the thing to be concerned about. Sure it's a factor, but there is such a thing as too powerful. 5500W is likely going to make a volcano out of a 5 gallon batch.

But... using a PID to control a boil is overkill, IMO. The whole point of a PID is to use a control algorithm to anticipate temperature changes and adjust things to maintain a precise control. It's essentially a very smart and accurate thermostat. Unfortunately, the temp of a boil is constant regardless of the strength of it, so a PID really can't do what you need.

Those that use PIDs to control boils actually use them in a "manual mode" which doesn't even utilize actual PID control algorithm at all. It just generates a manually defined pulse to control the percentage of time that your heating element is ON vs. OFF. The temp probe can be left dangling in the air when using a PID in manual mode... it's not needed.

Anyway... you can generate a pulse for much cheaper than the price of a PID.

GreenMonti said:

"IF" one is available, an infinite switch will give the same control as a PID/SSR all in one unit. Like an electric stove does.

Click to expand...

I just had a conversation on here the other day about infinite switches. They do generate a pulse, and are a nice off the shelf, complete solution for controlling boil strength. But, it sounds like the biggest ones available can only handle 15A, which is sufficient to drive a 3500W element @240V, but not 5500W. You'd need 25A for that size element.

The other alternative is to build a simple pulse width modulator. I've built a couple of these recently and it literally costs less than $5 to make one. It does take some time to assemble with a soldering iron, but it consists of one potentiometer, one small chip, two capacitors, and two diodes. You still need an SSR for the modulator to control, but it's a lot cheaper than paying for a PID that you will be under-utilizing by putting it into manual mode.

If you want convenience and/or the possibility for other system changes in the future (HERMS or RIMS or automated heating of water to set temps) then a PID that supports manual mode (note that not all of them do!) is probably a good choice.

If you want cheap 5500W boil control and aren't afraid to solder some things together, then a DIY pulse width modulator and an SSR might be what you want.

Thank you for the information. I want convenience + the possibility for other system changes in the future, and picked up a PID with manual mode fairly cheap.

That said, I would love to see a diagram of the simple pulse width modulator.

As I mentioned, this is the first step of a much bigger project for me. My induction heat-on-demand unit is actually going to be coded through an arduino I already have, to adjust flow rate of the incoming water, electric pulse, and wattage, in order to hhave the water exiting be at a temperature that I dial in.

I may as well hijack my own thread at this point, but I am working toward the following setup:


1) Electric Kettle
2) Reservoir / Mash Tun
3) IHWOD (Induction Hot-Water-On-Demand) hose unit

My brew process would be as follows:

Put grains in Mash Tun, use IHWOD to put water in at a preset temperature. Mash. Use IHWOD in place of an HLT for additional water. Pump into Kettle. Boil. Done.

The kettle I have at the moment is a cheap one that I plan to eventually replace. Therefore, I am putting together the equipment and systems I want, as I can get them together (time + beer allowance). My last purchases in this plan will also be the most expensive. First will be a nice, big metal container for my mash tun. Second will be a nice, big new kettle. Third will be a conical fermenter.

Once I am into the conical, I will start on my ideas for refrigeration instead.

And, to quote SWMBO: "He never does anything the easy way, but he sure has fun doing it."

But, at this stage, I'm just trying to boil me some beer, because my new home doesn't have existing facilities that make it easy for me to brew, and I want to go electric. And some evil part of me thinks that this all, somehow, makes sense. I'm not entirely convinced that part of me is right, but hell, I'll have fun tryin'!

- M

PS: I tried to find an infinite switch for this, never found one.

maztec said:

10 gallon and 5 gallon batches, same kettle.

5500W, ULWD element. Assumed 100% energy transfer efficiency since it is inside the kettle, so that is 18,766 BTUs.

1 BTU raises 1 pound of water by 1 degree Fahrenheit in 1 hour. (Gallons * 8.3lbs/gallon * (Boiling - StartTemp))/BTUs = time to boil.

For 10 gallons starting at 70F to boil it is: (10*8.3*(212-70))/18766 = rounded up 38 minutes to boil.

For 5 gallons starting at 70F to boil it is 19 minutes.


These seem like reasonable times to me. Furthermore, if I install a PID/SSR, I can manage the degree of boiling so it is a nice rolling boil rather than a thunderous turn the pot over boil.

Click to expand...

This is exactly right. Last night while doing test runs with the BCS-460, it took me 8 mins to get 5gal at 60 degrees to raise to 160 degrees, and 22 mins for it to boil.

maztec said:

I would love to see a diagram of the simple pulse width modulator.

And, to quote SWMBO: "He never does anything the easy way, but he sure has fun doing it."

Click to expand...

Sounds familiar. SO, to that end, here's the pulse width modulator. It has a fixed frequency (you determine this when selecting the green items) , but a variable duty cycle:


You need DC power for it. I used old/abandoned cell phone chargers.

maztec said:

10 gallon and 5 gallon batches, same kettle.

5500W, ULWD element. Assumed 100% energy transfer efficiency since it is inside the kettle, so that is 18,766 BTUs.

1 BTU raises 1 pound of water by 1 degree Fahrenheit in 1 hour. (Gallons * 8.3lbs/gallon * (Boiling - StartTemp))/BTUs = time to boil.

For 10 gallons starting at 70F to boil it is: (10*8.3*(212-70))/18766 = rounded up 38 minutes to boil.

For 5 gallons starting at 70F to boil it is 19 minutes.


These seem like reasonable times to me. Furthermore, if I install a PID/SSR, I can manage the degree of boiling so it is a nice rolling boil rather than a thunderous turn the pot over boil.

Click to expand...

A couple other things to add to the calculation...

Your starting volumes will be greater than you used in your calculations, you have to allow for evaporation.

And the other; when starting the boil you will likely be starting with wort that is much warmer than 70f, assuming you drain your MT into the BK and start the boil right away.

Good point Ed!

So, I bought an oversized o-ring, put it on, tightened the heck out of it, and wallah! No leaks.

Thanks for the help everyone.

When I go up a pot size, I am definitely going to have someone help me weld in bulkheads, so I do not have to go through the hassle of getting the hole to seal again.

Walker said:

Sounds familiar. SO, to that end, here's the pulse width modulator. It has a fixed frequency (you determine this when selecting the green items) , but a variable duty cycle:

You need DC power for it. I used old/abandoned cell phone chargers.

Click to expand...

Thank you for the diagram.

That is very simple to build. I have a couple of 555 timers on hand even.

555's are great! Thanks for the circuit!