The down side of that is the cold break ends up in the FV.
I know some commercial breweries allow this but most go to great pains to avoid.[/quote:2ahyu15d]
It doesn't seem to matter though.
Picked the following up at: [url:2ahyu15d]http://www.beerandloafing.org/hbd/fetch.php?id=15222[/url:2ahyu15d]
"After touring through a few breweries, it is clear that
cold break sediment is nowhere near as threatening as it seems at first glance; the most common systems create a cold break but do nothing to eliminate it. Consider, then, Jean de Clerq's statement: "It is therefore essential, that while the sterility of the wort is assured, it should (1) absorb sufficient oxygen during cooling, (2) coagulated protein should be entirely eliminated, and (3) the turbid matter which appears during cooling should be at least partly precipitated, _so that it does not remain as a fine colloidal suspension in the beer_." (emphasis added). In other words, what's essential is ensuring the break; once precipitated out, the material will only cause problems if it is redissolved by raising the temperature again.
George Fix writes that "in preparing my book on brewing science I tried to carefully study the effects of cold break carryover, and found that as far as finished beer flavors were concerned there were none." In that book, in fact, Fix explains that in adverse conditions such as a shortage of oxygen, the trub can be utilized in yeast metabolism. He cautions, however, that bacteria can use trub in the same way. "If bacterial levels are sufficiently low both in the chilled wort and in the pitching yeast, then I believe there will be no problems from cold break
carryover." With proper sanitation, then, and the use of pure cultured brewing yeast the carryover from cold break should not prove a problem to the homebrewer. "
If the question is whether plate chillers minimise infection risks better than immersion chillers, then I don't think they offer any significant advantage (in fact they may pose slightly greater risks depending on how well you filter the beer between the boiler and the plate chiller).
But if the question is are they more practical/efficient than immersion chillers, then I'm not so sure. It's probably true that they ensure a better cold break, but if you have to allow the wort to settle in a vessel before racking it to the FV then there is no time saving (quite the opposite in all liklihood) and the effort involved in sanitising two vessels and racking between them starts to seem unnecessary.
Using a filter down stream from the plate chiller would eliminate these hassles but only by replacing them with others. First there is the fact that you would be using two filters, one between the boiler and the chiller and a second between the chiller and the FV. Wort takes time to move through filters, Moreover, filters also need to be sanitised, which involves even more time consuming work.
If plate chillers don't minimise infection risks to any significant degree, and if they involve extra work to sort out the cold break material, what is the big advantage of investing in one in the first place?
If you have a half decent immersion chiller you can still achieve a good cold break, and there are various methods for draining the boiler quickly to avoid excessive infection risks. Add to this the fact that immersion chillers are cheaper (much cheaper if they are homemade), I'm just not sure I see the point in using a plate chiller in a homebrew set-up.
Can anyone think of any other major advantage to using them?
I should have said that if you don't care about cold break material getting into the FV then plate chillers probably are more time efficient. But cold break material seems to be a major concern for brewers of certain beer styles, particularly lagers (or so I have read - this could be overblown though).