So I brewed a Corona clone lager last night using my modified steam mashing system. It worked very, very well. I watched a movie for most of the brew session.
If you recall, my last session had a number of problems. First of all the braid floated when used for steam injection. Secondly, the braid turned out to be plastic rather than SS.
So I purchased a new braid and bent a piece of copper welding wire to keep it a) open and b) at the bottom of the mash vessel.
The mash schedule for this beer called for 30 minutes at 122F, followed by an hour at 148-152F. The reason for the first step is that 25% of the grain bill was cracked corn and one needs all the enzyme power one can get to convert it to sugars.
The mash in was done as normal, 1.33Q of water mixed with the grain. The mash temp came out right on, so all I had to to was close the lid and wait.
Meanwhile, I set the pressure caner pressure to 15 PSI, turned up the heat and went back to watching the movie. Brewing is such hard work !
Here is a picture of the pressure control and the control valve on my caner.
If the fittings look ratty, its because they are used, from my spare parts bin. Now that I know this setup works, I'll rebuild it with nice shiny fittings. Note that the valve is missing its piece of rod that serves as the handle.
After a while the pressure in the caner builds up and it starts rattling the control weight. I turn the temp down to low and go back to watching my movie.
After a while at 122F, actually during a commercial, I opened the valve on the caner and steamed the mash up to 152F. It takes about 4-5 minutes, depending on how ferocious you want the bubbling to be. Good news, the braid no longer lifts up. Most of the steam still comes out near the entrance to the cooler, which means one needs to manual mix the mash to distribute the heat. No big deal, but its a place for improvement in future designs.
The recipe called for 1 hour, but I let it sit for longer while I was doing other things. I boosted the temp once to keep it above 148F. My total mash time was one movie errr... 2 hours long.
I really like the fact that coolers hold the heat so well. The fact that one doesn't need a HERMs pump running means that the system really doesn't need any attention while it is sitting. The worst that can happen is the temperature falls a bit to much and you have to boost it and add a bit of length to the mash session. This makes for very stress free mashing !
When the movie was done, I steamed the mash temp up to 170F for sparging. Again it only took a few minutes. Steam works very well for heating the mash.
Once the grain bed was up to 170F, I disconnected the caner and set it aside and used the steam hose to drain the bed into the boil kettle. I put a piece of tinfoil over the top of the bed and added a bit of 173F water. I collected a couple quarts of wort and poured it back over the bed. Then I ran the wort directly into the boil kettle.
I used this little device to control the flow rate. (I also have a pinch valve on the hose near the cooler port. )
You can buy these at an automotive parts store. They are inexpensive. They are used to pinch various hoses shut when working on a car.
The sparge is very leisurely as well because all you have to do is add water to the top of the grain bed every now and again.
After that it was the usual boil, chill and ferment. The whole brew session was smooth and painless. The sessions go really fast because just about everything runs hands off and the temp increases occur very quickly. Very low stress. In fact, I now plan my brew sessions to happen while I am doing things with family. We have dinner. I set everything and mash in and just leave it sit. Sometime during the evening I sneak away and boost the temp and leave it sit. After everyone has gone to bed I sparge, boil, cleanup and chill. The actual amount of time it takes is quite low.
I am very happy with how this works and how small batch/kitchen brewing works. Kitchen brewing will never replace full on brewing for me, but its a great process for doing test beers and small batches of specialty beers.
I've now done 4 AG brews in the last 4 weeks. 2 with the microwave and 2 with steam mashing. Steam mashing with a cooler is way, way better. I really like how one can have the steam all built up ready to go and when you want to heat the mash, you just open the valve. No worries about recirculation rates or having the HLT at the right temp or pump oxidation or wort burning or anything. Just open the valve and stir a bit.
Steam heating works so well that I'll be using the corny boiler on my full size brewing stand.
Edit: I forgot to mention the efficiency. I measured SG pre boil. I got 4 gallons of 1.042 wort from 6 pounds of grains. 4x42/6 = 28 points. Theoretical is 35 points so thats 80%. I'm doubting the volume part though... it might have been less than 4 gallons. And yet after I boiled, I still had 3.5 gallons, so... lets say 75% efficiency anyway.
I was surprised that the efficiency was that good with the braid. I was always worried that the wort wouldn't wash as well with the braid because it has so much less surface than would a false bottom. But it seems to work OK. I tasted the spent grains as we emptied the mash vessel and there was no sweetness even from the grains in the corners. So they must have washed OK. The other thing was that this recipe only uses a partial sparge to avoid picking up tannins. So the sparge water volume was less than 3 gallons. If any mash could have given low efficiency, it was this one. And yet it worked well.