[cyzza]

Hey all,
 New to brewing, second brew in.  I bought a floorstanding burner after trying my stove, which enabled me to get a much more vigorous boil, but I think it was too vigorous.

I started with 6 gallons in my kettle, but ended up with 3.8 left over after the 60 minute boil.

Most guides outline to start with 6 to eventually get to 5, but I lost 1.2 more than that.

So I assume either:
a. less intense boil
b. start with more water

Any recommendations?

[Stevie]

Your boil could easily be too high. You don't need a big rolling boil with lots of foam.

[zwiller]

There are a couple of ways to skin this cat.  Myself, I do 30m boils and save the time and propane but as a new brewer you might benefit from sticking to 60m boils until you understand more.  I am with Stevie boil sounds like boil was too high.   

[brewinhard]

There are a couple of ways to skin this cat.  Myself, I do 30m boils and save the time and propane but as a new brewer you might benefit from sticking to 60m boils until you understand more.  I am with Stevie boil sounds like boil was too high.

+1. Low vigor boil is sufficient enough to drive off nasty volatiles.

[The Beerery]

60 minutes here with .5gal (6%) boil off. Soft boils are a thing of beauty.

[barbellsbooksandbrewing]

cyzza,
Do you keep the lid on, or at least partially on? I use a 10 gallon pot and do six gallons pre boil and end up with five gallons post boil. I also keep a thermometer in there and keep the heat at about 212-220.

barbellsbooksandbrewing

[mabrungard]

As proven in pro systems and by homebrewers (including myself), keeping your kettle largely covered does not result in adverse results such as DMS in your beer. Covering your kettle is a win-win situation. You use less energy and you lose less water. Hop utilization is completely unaffected by the boil vigor as long as your boil is moving the wort. Utilization is a factor of temperature and boil vigor does not change the temperature of the wort.

I now keep my kettle almost completely covered. I have a crescent opening of about 1" max width and I now have limited my total evaporation to about a half gallon for a 5.5 gal batch. I also never boil for more than an hour now. Longer boils are OK if the beer you are brewing relies on Maillard browning or oxidation notes (ie: barleywines, old ales, etc), but virtually every other beer is better without those effects. The myth of Pils malt wort needing a 90 min boil has been disproven...don't do it. I was once a believer in that myth and I've also proven to myself that I don't need to do that.