I have fermented my last - lemme go count - 14 batches in unmodified cornies. All my dip tubes are factory, but I use the ones with a straight tube and the wee flat space on a radius for primaries.
FWIW I think of the straight beer out tube kegs as my primaries, the ones with the curved tube and golf ball sized dimple smack in the middle of the bottom as serving kegs. To tell them apart, pick it up and look at the bottom from the outside. If there is one round dimple in the middle it is a curved tube serving keg in my world. If there is a flat part reaching from the center to the edge, it is a straight tube primary. You should notice that the flat part of the bottom points straight at the same point on the circumfrence occupied by the black (out) post.
I transfer (rack) exactly as described by Danaldor above. My transfer hose is about 8" long, black post to black post.
I have, so far, one batch that plugged up the works. For that one I had to open the lid and siphon the usual way.
Whenever possible I use whole hops and run the hot wort through the same BIAG mesh sack I use for lauter and sparge. When I have to use pellets I use twice enough Irish moss, whirl like mad, wait at least 25 minutes and siphon carefully.
With 5 gallon ales I have got to keep the fermenter in a water bath and keep the max temp under 70°F max, 65°F max is better. Hotter than that and I have yeast all over the room. Some pics of same in my gallery.
With wheat yeasts I just pitch on four gallons.
I am "never" going back to plastic buckets and I hope I "never" own another glass carboy.
Yeast harvesting is a snap. Just open the lid, pour in a gallon of clean water, replace the lid. Grasp by the handles and shake. Hook up the gas. Hook up a sanitized tap. Squirt yeast slurry into first (sanitized) settling jug as illustrated in the sticky.
I also bottle from kegs now. When I decide to bottle a batch I just boil up whatever for priming sugar and dump into an empty serving keg, then rack the beer onto it from whatever keg it is in.
I suppose I could make up a special bottling tap, but I have been just using my standard 10' of 3/16" with a black post at one end and a picnic tap at the other. Insert clean racking cane into opening of cobra tap. Line up bottles on counter. Hook up CO2 to grey post on primed flat keg. Fill bottles.
I think of the cold side as all my brewing equipment that touches cooled wort or actual beer and therefore needs to be sanitized, not just clean. The hot side gear should be clean, but if it isn't sanitized I am going to boil the wort anyway.
I will say the last three kegs to join my herd have longer gas in tubes than I have ever seen before. Those I might cut down a little bit, but they are all three of the curved tube/ serving type, so I don't really have to. As primaries the grey tube would be cutting into my head space.
Advantages to all cornelius cold side:
1. No glass carboys to break.
2. No delicate plastic surfaces to scratch and consequently harbor bacteria.
3. No UV worries.
4. Very tolerant to temperature.
5. Convenient carry handles.
6. Interchangeable vessels/ streamlined process. I can ferment, age, bottle and serve from all the same containers.
7. Not finicky to sanitize, I can use whatever product I want.
8. Dented cornies can be hammered back out with a rubber mallet.
9. Can be stored sanitized and pressed with a little CO2 more or less indefinitely, thus I can brew anytime without having to check if the primary is clean.
10. All one container type. I usually wait until I have three or four (used, rinsed) backed up before I bother breaking out the OxyClean.
11. Since I can harvest yeast out of cornies I am somewhat less interested even in conicals.
12. Can tolerate spunding valves/ pressurized primary ferments.
13. Carboy brush is quaint reminder of bygone era.
14. Cornies tolerate sharpie marker labels directly on bare steel, cleans up easily with hot water, OxyClean, green scrubber. Just to the side of the black post in case of drips...
Disadvantages:
1. More expensive than buckets, more expensive than carboys. Cheaper than conicals though ;-)
2. O-rings are less durable than glass.
3. Several parts to keep track of, organizational skills required.
4. Multiple surfaces means cornies are less forgiving of marginal sanitation pratices.
5.
EDIT: A couple recurring themes in my PM box.
1. Should I cut my diptube to use a corny as a primary? The real answer is I don't know. I like to leave enough room in the bottom of my fermenters to leave behind about a quart of yeast. From there I can go to the yeast washing sticky and save a few bucks on the next batch. My current herd is 8 cornelius kegs, and just when I think I have seen it all I find something new.
In general the straight dip tube cornies are perfect, but I only have three of them. One of the last three kegs I bought had a curved tube that was too long by over an inch, the last inch of the dip tube had to be forced into the keg before the threads on the post could mate with the threads on the keg. Yes I cut that tube down some and yes the Oring under there was toast.
2. What batch size can I ferment in a five gallon corny? It depends on your yeast strain, and it depends on how well you control your fermentation temperature.
With wheat yeasts I do four gallon batches. Those are in general agresive foamy yeasts and they need some head space.
With Brit and USA ale yasts, and temp controlled to 70°F or less I am perfectly comfortable filling the vessel to the weld line at the top where the vertical sides meet the curved roof. A few example pics in my gallery.
