If I'm not mistaken, the Picobrew Zymatic doesn't boil at all. And apparently, many brewers are making quite acceptable brews with them. I use a rolling, but not violent, boil.
I plan to get a Grainfather when I can.
Yep -- no need for a vigorous boil -- and (most likely) no need for a full on 212F boil (or whatever the temp for boiling is at any given location).
My Pico recirculates during the 207F 60-minute "boil" phase. And it's this re circulation @ 207F that works fine to drive off the DMS. In fact, I've had a truncated Pico session due to an issue with the Pico's PID -- and I made a pumpkin ale with a 25 minute boil -- and it turned out fine, no issues. The finished beer -- after 2 weeks in the fermenter w/Safale-05 -- clocked in at a 4.2 pH -- which is normal for an ale post-ferment and finished. Taste-wise is was perfectly fine. I had the mash at a 5.3 pH, added fairly equal amounts of gypsum and calcium chloride for the mash, and hopped with magnum for bittering. After I realized the boil was cut short, I added 1oz of Citra at flameout for 15 minute stand. Finished beer is fantastic -- no off-flavors whatsoever.
Some folks -- myself included -- are coming around to the fact that the "vigorous boil" thing is a myth. In fact, the 60 minute boil is (probably) a myth as well. See the recent Brulosophy entries on the short boils (
http://brulosophy.com/2015/09/14/boil-length-pt-2-pilsner-malt-exbeeriment-results/). (Hop utilization is obviously another issue with short boils -- so a long boil is necessary for hop levels -- but it's not *necessarily* necessary for all the stuff you're warned about -- especially DMS.)
My 120V Blichmann BoilCoil in my BIAB system does a perfectly fine boil -- a calm boil, but a full-on boil nonetheless -- and I've been saving 30min or so from my brewday by doing 30 minute boils for more malt-forward beers.
On the flip side, a vigorous boil probably doesn't hurt anything -- and if you can do it, great. But after 65+ batches with my Pico -- and always having the "boil" at 207F -- I'm churning out great beers. Not a hint of DMS -- ever. I suspect all current -- and all future -- 120V systems with 2250W heating elements will have calm and not vigorous boils. Hopefully, this doesn't dissuade potential brewers. The convenience of a 20A 120V system is fantastic -- especially for those of us who (for many years) fussed with propane tanks or fretted over 240V outlet installs.
One downside to the Pico's 207F boil is that I've noticed that hop extract (HopShot, for example) doesn't work quite like it does in a regular boil kettle. It seems that the extract (for super hoppy beers) needs the full boil (vigorous or calm) to do its thing. I say this because I've noticed big globs of hopshot in the bottom of my Pico's kegs after I bottle. I've never noticed this in a regular boil kettle.
YMMV for this, though -- but it would be an interesting experiment.
Also, see:
http://brulosophy.com/2015/11/12/short-shoddy-my-1-hour-all-grain-brew-day/
The other issue I've noticed -- and it's something that actually moved me to purchase a BIAB system in addition to my Pico -- is that for the life of me I cannot make a super hoppy beer with my Pico -- at least not by relying on the hop compartments and the Pico's automation. I can dangle hop bags in the boil kettle -- and this seems to work -- but it's not as automatic or hands-off as I'd like. This is the main reason I purchased a relatively low cost BIAB 120V system -- hoppy beers. The Pico makes great malt-forward beers -- superb, actually -- but I can't figure out how to bring the hops front and center with the Zymatic.
I'm guessing that the Grainfather -- because it doesn't rely on recirculating wort through adjunct compartments -- doesn't have this problem?