Boiling with steam?

I've read some of the threads about using a pressure cooker and wand manifold to do step mashing. This seems easy enough and I will build it when I can get my hands on a pressure cooker.

This has me wondering......?

If I use a large (23 QT) Pressure cooker and build a larger manifold (12" circular with 3/8 copper) could I boil 10 gal of wort/water?

I would use a large electric range burner for the heat source.

Any input would be great

Thanks

Bull

There is no advantage to trying to boil with steam, the boil rate is still determined by the size of the heat source. If you want to try this use your immersion chiller and pass the steam through the copper coil from the top down and vent the condensate into a bucket or drain. If you try to inject the steam directly into the wort you will find that the steam will cause a lot of noise unless you use a manifold with a lot of very small holes. The biggest hurdle will be the ability to maintain steam pressure and water level in the pressure cooker for the time needed to do a 1 hour boil. The ability to store heat in the pressure cooker is not that big in reality, after the initial blast of steam you will have trouble trying to maintain pressure with a standard stove element. I have built and used flash boilers to produce steam on 2 systems and am able to heat water and generate superheated steam on a continous basis for wort heating. I still direct fire the boil kettle because that is the most efficient method for the money to get the high btu's needed to raise the wort from mash temperatures to boil.

Are you planning to conduct the mash in the pressure cooker itself? I have heard of injecting steam into the mash for step mashing but not this (if I'm reading correctly). Maybe some more detail to help clarify.

Edit: Nevermind I read Klaude's response and I understand what you're asking but don't have any good input. Sorry.

It sounds like he has planned to make a steam injection wand ala heat stick for mash heating, he will find the same problems with injecting steam into liquids, you need to make the steam bubbles small to control noise. The other problem will be the ability to generate enough steam for large temperature steps with a stove element heat source.

Thanks for the input so far.

My main concern was being able to maintain the steam pressure.

I read somewhere that the steam condensation rate and the boil off evaporation rate are nearly the same, so I want to directly inject the steam into my boil via manifold with many 1/16 th inch holes.

Most of the enegy is transfered @ condensation

Using the wand in the mash tun in order to step mash should still work as the time needed to raise the temp up 30 degrees should only be aprox 20 min.

I have taken a couple minutes to work out the effects of direct steam injection dilution. Here are the assumptions:
Starting wort temperature: 160 degrees:
Btu,s added to 212 degree water to boil 1 Lb water: 970
Pounds of water in one gallon: 8.45
Batch size: 5 Gallons
BTU's to raise wort to 212 degrees: 2197 Btu's
Pounds of steam needed: 2.26 Lbs of steam
BTU's to bring 1 gallon of wort to boil: 8196Btu's
Pounds of steam needed: 8.45 Lbs of steam
Total pounds of steam to achieve 5 gallon boil: 10.71 Lbs of steam
Total water added to reach boil off equilibrium: 5 Qts water

It would appear that the dilution of the wort will require a bit of adjustment to the recipe to compensate for added water. I use a 1/4" X 1" SS screen wire diffuser for steam injection into circulating wort, the turbulent mix area controls noise by limiting steam bubble size.

The 5 qts added basicly equal my loss to evaporation.

So if I start with about 20 qts of water in the pressure cooker and lose 5 qts. to steam over the course of the boil, will the thermal mass in the remaining water generate enough steam pressure to maintain a boil?

The problem I believe will be in balancing the amount of steam to boil the water and still maintain pressure.

I'm really excited to try this but don't want to waste my time and money if it won't work.

Thanks again

Bull

The 5 Qts added to the wort will be added just to get to a boil, after that the steam added will be slightly more than the boil off rate because of heat loss from boil container. So the 5 gallon batch size will grow to 6.25 and more as you go through the boil because of container heat loss. The main problem will be the heat source for the canner, normal electric range elements are about 1.7 Kw(5800 Btu's) and the "Canning" elements are 2.0 Kw (6826 Btu's), both will be below the needed amount to maintain a boil at 1 gallon/hr rate. I would lobby for the closed tube heat exchange as the easiest way to get to a boil without adding water to the wort during the boil. As I stated before it would be possible to use the immersion chiller for the heat exchange coil and heat the wort with steam from the canner. You should expect the water consumption during a boil cycle to be at least 2 gallons to allow for heat loss from piping and boil vessel, it would be prudent to load 50% more water into the canner for a safety margin.
All things considered it would be safer and easier to follow the conventional direct fired route for wort boiling, but if you want to go the steam boil route it appears that the heat source will be the hurdle to cross.

Thanks for your help with this.

The reason for my interest is that I have an all electric house and would like to build a brewing room in my basement. I don't want to direct fire inside and direct heating with electric burners is slow and inefficient.

I am currantly brewing 10 gal AG batches with propane and would like to continue with this size.

I would like to keep this simple.

Other suggestions? Steam boiler or 240v steam jacketed kettle are both very expensive.

Bull

Use a water heater element in the kettle itself. Besides, if you're planning on creating steam over the same inefficient electric burner, you're adding another layer of inefficiency. Steam won't magically create more energy for you.