Friday, 6 April 2018

A Modern Lager Brewery - malting

We're back looking at a modern Lager brewery. Or at least what passed for one in 1917.

This passage on malting has some useful tidbits. But also confused the hell out of.  In particular, the bits about using hot air for kilning.

"Malting.—The Continental system of pneumatic transport is now familiar to every English brewer, while barley cleaning and grading machinery offers a very limited scope for invention in any country. That steep aeration is advantageous is generally conceded and the foreigner has undoubtedly given much attention to this matter, for the latest form of aerating appliance not only forces fresh air into the grain, but draws away the bad air and effluvia present among the corns, it being claimed for this combined treatment that it ensures a quicker start and more uniform growth, together with sweeter and healthier floors.

All systems of germination are employed—the old-fashioned floor, the Henning Drum and the Saladin Box, to mention those best known, while the Kropff system is said to be yielding satisfactory results in respect of economy of working, increased yield and mellowness of the malt produoed. Mechanical floor turners are in use at the Brasserie Maxeville, at Nancy, France, where "two of these machines have successfully dispensed with the services of ten men.

The kilning of the malt differs from the system in vogue in England. In the first place always two and sometimes three floor kilns are used, while hot air only is employed for drying and curing, the products of combustion not passing through the grain. Two forms of kilns are employed, one with horizontal heating tubes, known, curiously enough, as the English kiln, and the other, the Calorifiere, with vertical tubes. By a convenient arrangement of dampers and shutters, hot, warm or cold air may be passed through the upper or drying floor, and almost any degree of heat obtained on the lower or curing floor, whereby all classes of malt, from the palest Pilsener to the darkest Munich may be produced.

Interesting as a description of the making of the various malts would be, space will not permit of more than a passing glance at the general outlines of Continental practice."
Journal of the Institute of Brewing, vol. XVII, 1920, page 490.

Why did the hot air confuse me? Because the implication is that it isn't how things were done in Britain. But I thought kilns using indirect heat had been first developed in the UK. Am I missing something here?

Johnny Foreigner paying lots of attention to steep aeration? There must be something dodgy about it, then. I don't really have an opinion on the topic, myself. Knowing bugger all about malting, as I do.

Want to know some more details of steeping and kilning? Of course you do.

"Steeping and Kilning.
A Moravian barley will be steeped 88 hours.
Temperature of water 50° F.
Water changed 8 times.
Growing period 10 days.
Turned 25 times.
A short growing period would be 7—9 days.
A medium growing period would be 9—11 days.
A long growing period would be over 11 days.
Sprinkling, if needed, may take place on the 5th, 6th, or at latest 7th day.

Atomising the water into the form of mist over the growing pieces is much practised on the Continent, being obviously less conducive to irregular growth than sprinkling with a can.

The finishing temperature (in the malt) for the three types of malt employed in lager brewing vary as under:—

Pale 140° to 178° F.
Medium 196° to 207° F.
Dark 201° to 212° F.

Particulars of treatment on the kilns:—
For pale and medium malts... 12 hours on upper (drying) floor.
                                                12 hours on lower (curing) floors."
Journal of the Institute of Brewing, vol. XVII, 1920, pages 490 - 491.

I'd love to tell you how that tallies with UK practice. But I can't be arsed to look it up. That would entail walking upstairs to the library. Maybe tomorrow.

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