In article ,
David W.E. Roberts wrote:

Then when you mash it, the maltose has to be extracted within a very
tight temperature band, about ±1°F for lager malt and ±1°C for English
type beer malt.

Here is where Rusty/Jaques and I part company.
Real home brewers use fresh malt, and can make outstanding beer with home
mashing. You can get mashing tubs with electric heaters and thermostats
which can turn the art into more of a science. You may not get the same
extraction rate as a commercial brewery, but then you just accept that you
are going to be a little less efficient and allow for that in the
quantities.

Indeed. I used to use malt extract for making my own beer, but now work
entirely from crushed malt and (IMHO) the results are far superior.
Most of the home brewing books I've read suggest that the mash can be
carried out in an unheated, insulated plastic brewing bucket, so I
cannot believe that the mash is that temperature sensitive.

Just checking though the closest book to hand, it suggests an acceptable
temperature range for mashing of between 62C and 69C.

It is much more sensible to buy spray-dried malt extract.

The (not good but vaguely competent) brewer in me recoils from this heresy
:-))

Ditto.

James