At what temp would you consider your wort to be at a good "rolling boil"

Hey, I've made 8 batches so far and just trying to make my process better. I so far have done only extract partial boils and i want to make the best brew possible. What temperature do you boil your wort at and at what temperature do you consider it to be a "rolling boil"

I know i start to get a rolling boil at about 210 but would consider it a light rolling boil. I use a standard candy clip on thermometer when boiling my wort and it does not go very deep into my kettle. since it is only about 6" long only about 2-3" are in the boil. The kettle is a 3 gal all clad pasta pot, so i know the temps near the bottom will be higher than at the top. I do have one of the floating thermometers but don't use it since there isn't enough depth to float it in my setup.

Water boils at 212F, period.

Okay, that's a half-truth. It's true for pure water at sea level. Higher elevation means lower boiling point (at 3500' where I live, it's about 209F I think). Conversely, dissolving stuff - like sugars - in water generally raises the boiling point. But when it boils, it doesn't really get any hotter except maybe in some local spots within the vessel.

The key isn't temperature, it's the boil itself. Is it rolling? Percolating doesn't count. It should be turning itself over pretty well. Here's an example: . . . though if you're low on head space in your boil kettle that might be a bit scary for you. The real danger is at the beginning when you get the hot break, as the foam really piles up until it starts to roll and really settle in.

Anyway, don't watch the thermometer. It's not a magic temperature, it's a function of how vigorously the liquid is boiling. In Denver, that might happen at 208F, in Seattle that might be 211F.

Here's a good boil temp...

SilverZero said:

though if you're low on head space in your boil kettle that might be a bit scary for you.

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Yeah i def need a bigger boil kettle

scottab said:

Yeah i def need a bigger boil kettle

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I just got myself a 15-gallon pot yesterday. No more boil-overs for me! :rockin:

212 F (or lower based on elevation)

Once it gets hotter than that, it turns to steam.

Some of the brewing podcasts have gone into this. (My kettle can barely fit my batches, so I paid attention)

They all seem to agree, that as long as it's turning over, that's enough. One of them even noted that commercial breweries don't have big roiling boils going. Just a gentle, bottom to top rotation, with the occasional bubble, and a good amount of steam rising. Not a direct quote, but that's what I took away from the show.

I've done hard boils, and gentle boils, and I couldn't tell any difference.

I've always hoped for a 250 boil, but, alas, have been stymied by science...every...single...time!!!

Boiling temp is boiling temp. Once your wort starts to boil it doesn't increase or decrease in temp according to the vigor of the boil. You can have a vigorous boil at 212 or a gentle boil, again at 212 (It's different for me because of my elevation). The amount of heat (energy) you apply to the kettle will determine the vigor of the boil. Basically the vigor of the boil is how quickly you are converting the liquid to steam. Add more energy and your get a more aggressive boil, but not a higher liquid temp.

Hope that makes sense.

I live at around 5500 feet, so my wort boils at around 204 F.

I guess what i am really after is if the boil of a "rolling" boil is very vigorous like white water rafting or more gentle like tubing down the river.

scottab said:

I guess what i am really after is if the boil of a "rolling" boil is very vigorous like white water rafting or more gentle like tubing down the river.

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Vigorous would mean that the liquid is very turbulent and the surface is all bubbly.

Gentle would be a few scattered bubbles on a mostly calm liquid surface.

The rolling boil really describes the surface of the wort in the kettle from my perspective. If it is a placid surface without much boil action then you need to turn up the heat!

In cooking, a rolling boil is defined as a condition where stirring the pot does not decrease the activity noticeably. This is more vigorous than I care to mess with, because you are on the edge of a boil-over.

This thread reminds me of that Michael Keaton quote in Mr. Mom: "Yeah, 220, 221. Whatever it takes."

Classic.

There are many reasons to boil beer.

1) Hold the wort at a high temperature long enough to kill bacteria and the like. This does not really require boiling. Holding at 205 for an hour will accomplish the same thing.
2) Isomerize the hops. This happens at high temperature, but again, not specific to "boiling".
3) Remove DMS from the grain. For this, you need the high temperature and the movement of the wort.
4) Concentrate the liquid. This can happen at any temperature (evaporation), but is MUCH faster when boiling.

There might be others, but I can't think of them off-hand. Please add any I miss. The only one's that are directly affected by the vigor of the boil is 3 and 4 and 3 is a stretch.

This is one of those questions where it's valuable to know why you're doing what you're doing. For instance, sometimes I crank the boil WAY up if I'm high on volume or vice-versa. If I want a super delicate aroma from an herb or even hops, I may drop it way down for the last few minutes when I add it (more of a steep almost). If you've already accomplished your "boiling goals", why not?

ajwillys said:

.
2) Isomerize the hops. This happens at high temperature, but again, not specific to "boiling".
3) Remove DMS from the grain. For this, you need the high temperature and the movement of the wort.

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These would seem to be the important points, however since i have not been mashing grain would extract have much in the way of dms?
Isomerization should happen as long as there is enough heat so at a slow roll i would think this would still be accomplished...
so a vigorous turbulent boil may not be necessary to producing good beer from extract?
How about the protein extraction in the hot break, is this accomplished by vigorously boiling?

Removing oxygen from water is one great consequence of a boil as well. Something was stated above about removing bacteria via boiling and that ought only take 10 minutes or so.

scottab said:

How about the protein extraction in the hot break, is this accomplished by vigorously boiling?

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That's a good point. I don't have any data or real knowledge about it, but from my experience, a good rolling boil at the beginning does seem to help the hot break form. I also like how it pushes all to one area!

As for the extract issue, I have no idea. DMS would certainly be produced during the wort production phase, but might be removed during the evaporation/drying phase. I know people do late extract additions on partial boils (to aid in hop isomerization) all the time and it doesn't seem to be much of an issue.

maltoftheearth said:

Removing oxygen from water is one great consequence of a boil as well. Something was stated above about removing bacteria via boiling and that ought only take 10 minutes or so.

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Agreed, we don't want Hot Side Aeration (oxygen in hot wort). Of course, once the wort cools and we're ready to pitch, we want all that oxygen back.

For those of you scared of a boil over,Fermcap. Most brew shops should carry it.

It is food grade silicon that prevents foaming and thus boil overs.2 drops per gallon. It promptly sinks to the bottom and to is left behind when you rack your beer. You only have to really watch the boil at the beginning as the silicon is at the bottom and hasnt been stirred up with the action of the boil yet. Once the boil is established, you can walk away and only return for your hop additions. A boil over is still possible if you put a redonkulous amount of BTU's on it, but we are talking serious overkill to achieve this. Cheap and effective way to get a safe rolling boil without any chance of a boil over.

I find that a gently turning boil does the trick for me. Certainly less vigorous than what's in the video above. Try it both ways and see what tastes the best to you and yours. If you brew great beer nobody's gonna give a rat's rectum how hard you boiled your wort.

SilverZero said:

I just got myself a 15-gallon pot yesterday. No more boil-overs for me! :rockin:

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I thought that the first time I used a 15 gal. kettle for a 5 gal. batch. Guess what happened?

Denny said:

I thought that the first time I used a 15 gal. kettle for a 5 gal. batch. Guess what happened?

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Fair warning.

prrriiide said:

I find that a gently turning boil does the trick for me. Certainly less vigorous than what's in the video above. Try it both ways and see what tastes the best to you and yours. If you brew great beer nobody's gonna give a rat's rectum how hard you boiled your wort.

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I have been using the gentile rolling boil since i don't want a sticky napalm fire in my house... guess i will have to wait till i can upgrade my equipment to see if there is any difference.

TheCatman said:

I live at around 5500 feet, so my wort boils at around 204 F.

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This! It's the same for me but I've observed more like 202°F at about 5500 feet. But then again 212°F it's for pure, distilled water. Wort is a slightly different beast.

Rough rule on elevation (for those that are interested) is subtract 1°F for every 500 feet over sea-level.

Denny said:

I thought that the first time I used a 15 gal. kettle for a 5 gal. batch. Guess what happened?

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I've boiled over in a keggle before. Thankfully, in a garage, not a house. Thankfully even more, in Yeager's garage, not mine!

Boil over people. Try this.

Vigorously boil 2 gallons of water with a thermostat in place. Gradually reduce the temperature until you can maintain a temp of 100*C. Use a sharpie to mark the location on your propane regulator where it maintains 100*C.

If you do this right, you will never have a boil over again.

Perhaps instead of temperature evaporation rate would be a better measure. Either way just get it boiling fairly violently and either buy fermcap or use a spray bottle with water in it. Works like a charm.

scottab said:

I have been using the gentile rolling boil

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Better than the genital rolling boil!

The Jew rolling boil is more economical.

Denny said:

I thought that the first time I used a 15 gal. kettle for a 5 gal. batch. Guess what happened?

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the_bird said:

I've boiled over in a keggle before. Thankfully, in a garage, not a house. Thankfully even more, in Yeager's garage, not mine!

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Been here as well. First AG batch with a keggle boiled over. Even with a big boy kettle, set it and forget while bringing wort to a boil is still means for potential disaster.

maltoftheearth said:

Better than the genital rolling boil!

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The words genital and boil should never be used together in a sentence!

Oops i meant something other than auto-correct gentile! LMAO! Gentle, gentile, tomato, tomahto