Just a note - what you are proposing is certainly not what the wiki is suggesting. The wiki is suggesting raising the mash temperature from one step temp to another (eg. for a Hochkurz mash), not from room temp to mash temp.
Doughing in at room temp will give you a very gloopy mash, so you'd want to be sure that you're not going to scorch over the element. Depending on how rapidly or slowly you raise the temperature from room temp, you'll also get certain types of activity that you may not be after, eg. acid or protein rests.
There are lots of good reasons for mashing in cold, it was even common practice back in the old pre stainless steel and computer control (probably pre-electric) days. You actually get a better yield and better utilisation of all your enzymes.
Pre-hydrating (mashing in cold the night before) allows all the enzymes to go into solution (optimum temperature is about 48oC) allows the malt to fully hydrate, allows some otherwise reluctant starch granules to swell and burst making more starch available to enzyme attack...
Down side is its slower, in these days of 10 or more mashes a day in a big brewery it simply isn't possible, it also takes more energy (costs more). For a home brewer its a very valid option.
interesting points . my system has a grain basket with recirc into the basket was well as recircing wort around the 2 ULD elements. gloppy mash sounds like a precursor to a stick mash, I have rice hills that i could add to mitigate this. also yeah, the ultimate impact to flavour by the temp range. I can heat at 1c per minute or even faster. guess I'll give it a try and see?
This is a rule of thumb, but its a good one!
If you are heating faster than about 1oC/Minute you are killing enzymes.
It takes time for heat to cross materials, to heat the liquid and for the heated liquid to either move/be moved so more liquid can take up heat. if the energy is going in too fast the surfaces will be hot enough to denature enzymes at a minimum, to cause scorching and fowling of the heating surface at even higher rates.
There is also another mash regime that might surprise people.
If you mash in at ambient then heat to 80oC at 0.5oC/M (i.e. from 20-80oC over 120minutes) you will go through all the enzymes optimum ranges slowly enough for each of them to do all they are going to do. Think about it in design terms, just match the element power to the batch size, use a temperature (80oC) cut out switch, fill up, plug in turn on and come back in 2 hours. Stirring the mash or recirculating the liquor would improve consistency, but I have done this a couple of times on an electric stove top, set on low and just let it sit there for a couple of hours to pre-digest when working with a lot of adjunct.
Coalminer has the advantage of working on a Rolls-Royce system. when you are talking about Ultra low density elements, in a BM you can fill the unit with water turn it on, you can reach in and hold the elements in your fingers until the water is too hot to put your hand into (not recommended) without burning your fingers. That's real ultra low density elements and part of why a BM is more expensive - but you do get what you pay for.
When I home brewed on a BM, I took to mashing in with tap water (Cl removed) heating to 20oC if needed, doing all my water chemistry then just running up to first rest, consistently got over 80% efficiency in the fermenter. Worth noting that a BM will heat at pretty close to 1oC/minute.
Mark