Ways to increase boil temperature

DNW · 01-27-2009, 01:24 AM

In an attempt to lighten the color of my Hefeweizen, I did a 3.5 gal boil in my 5 gal kettle. It was borderline ok, but decided to partially cover it to get close-to-boil-over conditions, which is what I thought was desired. I've since found that it is most desireable to have the boil completely uncovered. However there was one other option I considered but didn't have anything to experiment with at the time. Has anyone tried using some kind of insulation around the outside of the pot to reduce heat loss through the sides? If so, how effective is it, and what did you use?

I do have a gas stove, but it only has standard (9000 BTU) output burners. Unfortunately, one of the models that we COULD have had has a 15,000 BTU "power" burner whicH I suspect would make a noticeable difference. Oh well, maybe next time...

The other thing I thought of was using a turkey roaster shaped kettle that would fit on two burners. Is this a feasble option?

Hefeweizen is one of my favorites, and while I'm satisfied with what I've been able to do, I really prefer the lighter color and would be very hapy if I could lighten it up.

evandam · 01-27-2009, 01:51 AM

Going all grain is one way to lighten up the color of your beers. I was never able to get them as light as I do now that I'm brewing all grain (Even though I find myself darkening them up to the top of that style). You could try late malt addition (If I'm not mistaken, that is going to change you hops utilization).

As far as the insulation, that will help in getting to a boil, but water is going to boil at what it boils at, 212 at sea level. 213 degree water is called steam. I'm sure there will be a brainiac out there that will try and dispute this.

Tech211 · 01-27-2009, 02:13 AM

You only need a rolling boil. A monster boil won't improve things for you. If you are worried about color then very high heat is your enemy. It will darked the wort.

Your best bet all around is to go for a full volume boil. If you can get a pot that will fit over two burners then go for it.

KayaBrew · 01-27-2009, 10:48 AM

Boiling is boiling...212 F or 100 C at sea level.

KayaBrew · 01-27-2009, 10:51 AM

There was a post up here a while back...I'll try to find it, but in the meantime, the OP wrapped foil insulation around the brewpot and sealed it with foil tape. You could also insulate with auto insulation-the kind that lines the inside of your hood and is lining the firewall.

KayaBrew · 01-27-2009, 10:54 AM

Found it! Some good pics here

http://www.homebrewtalk.com/f11/improved-boiling-stovetop-53683/

**JPicasso** · 01-27-2009, 12:16 PM

The roaster shaped pot would lose a lot of water to boil-off.
The link above looks promising, with he foil-type insulation.

Also, propane turkey fryers can be had for $30-$50. I would consider that if you have the outdoor space.

DNW · 01-27-2009, 02:20 PM

Thanks for the tips and link.

Just to clarify, I guess what I meant was to increase the temperature of the boil cycle, not the actual boiling process. I understand that water boils at 212°F at sea level and the only way you can change that is to modify the air pressure (such as with a pressure cooker). I was more interested in finding ways to raise the temp TO boiling.

BTW, on my last batch, in addition to going to 3.5 gallons (from the 1.5 specified by the original recipe), I also did 3# of extract at 60 mins and the remaining 4 at 15 min. I'm hoping that those two factors will contribute to a lighter color.

I have considered all grain, and would consider it even stronger if I thought I could achieve a full boil on my stove top, using some of the tips here. I do have plenty of room outside, but last Saturday it didn't top 10°F all day - not the kind of environment I look forward to spending my afternoon in...

Again, I appreciate the feedback. Will continue to improve my brew methods and abilities no doubt due to my learning here.

planenut · 01-27-2009, 03:22 PM

any chance of splitting it up into 2 2.5 gallon batches to boil and then combine in the carboy before pitching yeast?

CBBaron · 01-27-2009, 03:32 PM

Several problems with insulating a pot on a gas stove top.
First the insulation has to be fire proof because it can be in contact with flame.
Second it is the exhaust from the burning that transfers the heat to a pot. This hot exhaust not only transfers heat during to the bottom but also the sides as hot air rises. Insulating the sides of the pot may actually make the problem worse.

One thought I had would be to increase the contact between the pot and hot exhaust by putting a shield around the pot. You would need to let air in at the bottom for the burner but it could be a metal shield around the pot keeping the hot gases near the sides of that pot. The outside of the shield could be insulated for even better performance but its probably not necessary.

I have thought about doing this for my outdoors turkey fryer but have not yet implemented it.

However I don't believe this will have much effect on the color of your beer. It can effect the over all quality by boiling off DME precursors and increasing the hop utilization but color is more a matter of caramelization and melodins. These are caused by high heat applied to sugar. Increasing the rate of boil will not affect that much.

Craig