Doing some experiments in this area will seem silly to some. For example, I personally don't worry about evaporation rates much as I don't have a palate that is able to taste the difference between my single (19% evap) and double batches (9.5% evap) that are both done at a gentle to medium rolling boil.
ThirstyBoy spends a lot of time writing on here helping other brewers. Helping out other brewers can be a very enjoyable sub-hobby of brewing as you get to correspond or meet with a lot of great people. Giving bad advice is something that you never like to find that you have been doing especially with new brewers as they naturally take everything written on a brewing forum as gospel. That is why Thirsty wrote...
I like to be right.... And if I'm going to talk about this stuff and be arrogant enough to advise other people what I think they should do... I want to be sure what I am saying is true, not just that it makes common sense. I'm also arrogant enough to think that some people will be interested in watching me do it. Besides, playing with fire and boiling water is a lot of fun... Might make mud pies next (lol)
A new brewer often finds existing advice on evaporation rates and boil vigour daunting as some people will tell them to either do a good rolling boil, while others will say strive for 8-10% evaporation and brewing software will tell them it should be 15%. WTF does a new brewer do!
Many new brewers will also struggle with one of two things. A new stovetop brewer may struggle to get a good rolling boil going. Another with a large pot on gas might wonder why they are having to use heaps more water than everyone else.
This floatie idea of Thirsty's is a great idea. Mucking around yesterday on the stovetop was enjoyable and because I could "see into" the boil, I now know that putting a floatie in will decrease the amount of energy needed to create a rolling boil and it
did increase the vigour of the entire boil. And, so it should, as you have applied direct pressure to half the wort surface area. (Putting a lid 3/4 on a half-empty pot applies no pressure to the surface area and therefore doesn't do much to decrease required energy levels. Using a floatie may have also lowered the temperature at which the water boils - I never checked that (wink)).
What the above means I'm not entirely sure of because there isn't much literature out there on evaporation rates and boil vigour that is not based on commercial kettles. I don't know whether boil vigour is more important than evaporation rate or vice versa for example. What the floatie can do though is help us to get
both things right.
I of course, with my palate will not be able to taste any difference but maybe I'll save 5 cents or $5 on gas or something? I don't really care but I find exploring this stuff is enjoyable and occasionally does result in some forward moves. For example, a year ago a few brewers were enthusiastic and constructive enough to contribute some figures
here and from this we have been able to create some automatic formulas in BIAB "software" (though it can be as handy for traditional brewers) as to what evaporation figures they can expect from their particular kettle. In other words it gets them on track quicker.
So for those of you who find all this silly and/or pedantic, just know that there are a few brewers out there whose sub-hobby is exploring things like this and that sometimes it does make a whole new generation of brewer's life far easier and simpler which is obviously a good thing. (Most of the time it just keeps our over-active imaginations/minds amused and results in a shed full of shit
- you should see some of the stuff I have at my place
).
Evaporation rates and boil vigour
are confusing subjects for new brewers so any concrete and constructive exploration of these, I think, is a real plus. All these long posts
unsure
and arguments will eventually become some simple advice/formulas for new brewers. The current advice of turning down the heat and/or partially covering the kettle does not help a lot of new brewers. (It certainly didn't help me.)
I think the floatie will help them though so lets not sink it before at least taking it on a little voyage.
Hope this post wasn't too short or anything - lol,
Pat