Sunday, 9 November 2014

German brewing in 1966 - malting again

This time it's the final bit about malting. You're doubtless finding this as dull as I do. But once I've started something I feel compelled to finish.

Unless I can't be arsed. Which is quite often the case because, at heart, I'm bone idle.

Right, confession out of the way, we can get on with the tedious task at hand: trying to make automated maltings sound like fun.

"Mechanized maltings.—There is a limit to the mechanization of floor maltings. As labour requirement for floor maltings is high they are being replaced more and more by Saladin boxes or germination streets on the Wanderhaufen principle. The automated Saladin box with air conditioning by direct ammonia-cooling, or Freon evaporation cooling, permits the use of measured return air. Particularly in the case of single box units it is possible to adapt the malting process to meet all requirements. The emptying of the boxes is completely mechanized as a result of developments during the last ten years, thereby doing away with the strenuous and unpopular manual emptying.

Developments here range from the bulldozers of varied construction to the mechanical or pneumatic emptying system with a special turner, which provides a horizontal screw conveyor above the screw turner and thereby transports the green malt to a suction unit or a mechanical green-malt transporter. At the same time there are turning units with provision for direct emptying when the screws are stationery. Similarly, casting by means of moveable floors is becoming more popular. A new idea is the emptying of the total content of the box, by tipping floors, into a Redler transporter which takes the piece to the next box in the series. The turning in this case is very intensive.
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 16.

Saladin boxes had been around since the late 19th century, and were one of the earliest moves away from floor malting. I'll be honest with you: I don't understand this stuff well. So I'm going to let someone who does explain it a little more.

"In floor malting the steeped grain is spread on a floor in a room having a cool, humid atmosphere. Germination is controlled by turning the `piece' (batch) and thickening or thinning the layer of grain to allow temperature rises or falls as needed. Fine malts can be made in this way, but only in small quantities (ca. 10 t/batch) and with substantial manpower. Modern maltings are of the pneumatic type, in which the grain is turned mechanically and the grain temperature is controlled by forcing a stream of attemperated and water-saturated air through a bed of grain. Newer germination vessels are usually rectangular `Saladin boxes' or circular compartments. In these vessels steeped grain is formed into a bed, usually 0.6-1.0m (approx. 2.0-3.3 ft.) deep. The grain rests on a perforated deck, through which the conditioning airflow is driven. Some of the air is recirculated and mixed with fresh air. The air is driven by a fan and is usually humidified by passage through sprays of water. Air temperature may be controlled, by regulating the water temperature, sometimes augmented with heating or cooling by heat exchangers. The grain lifted and partly mixed, and the rootlets are separated by passing a row of vertical, contrarotating helical screws through the bed. The bed is `lightened' and the resistance to the airflow is reduced. Bed temperatures of 15-19 ºC (59-66.2 ºF) are common, with temperature differentials between the top and bottom of the bed of 2-3 ºC (3.6-5.4 ºF). The turner arrays are usually fitted with sprays to allow the grain to be moistened."
"Brewing: science and practice", by Dennis E. Briggs, Chris A. Boulton, Peter A. Brookes and Roger Stevens, 2004, page 21.

Is that all clear now? I though not. Let's quickly move on.

Here's another type of mechanised malting: a germination tower:

"Finally, the germination tower has been described a number of times, and this new type of unit is working very well in two maltings. When a few minor improvements have been made, we shall probably see more installations of this type.

The tower provides for aeration of the vertically stacked, slotted germination floors by means of ventilators. As the air has direct cooling, every possible range of the ratio of fresh air to return air can be employed. Additional jets must be provided to saturate the return air. The return air is controlled in order to provide the required temperature on each floor, i.e., for each germination day. As the CO2 in the return air slows down germination, one can work with 15-20 cubic metres of air per 100 kg. of barley per hr. This is considerably less than the average value for Saladin boxes (50-70 cubic m. per 100 kg. barley per hr.). Nevertheless, it is advisable to allow for a powerful ventilator, suitably regulated.

Loading and emptying is made completely automatic by specially designed tipping floors, and therefore no manual work is carried out. Control of temperature is carried out by the cooling unit. The aeration provides for a gradual increase in temperature from the top to the bottom, as the exhaust air of one floor is the new air of the next floor. In practice it is possible to start with a temperature of 12-13° C. and increase by 1-1.5° C. per day so that the oldest piece will be at approximately 20° C. after 7 days. If it is required to start germination at a higher temperature it is possible to reduce the temperature after the third or fourth day by means of a second air-conditioning cycle. The resulting malts are at least equal to box malts and full allowance must be made for the lower malting losses."
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 16.

Let's see if I've got this right. A germination tower worked totally automatically and the losses during malting were smaller than with a Saladin box. Sounds perfect.

As a special treat, here are the specs of Weyermann's base malts.

Weyermann base malts
malt colourEBC use amount comment
Premium Pilsner Malz 2.0 - 2.5 Premium Pilsner with an extra pale colour 100% made from the best domestic 2-row summer brewing barley
all other types of beer by selecting particularly suitable raw materials and applying a specific malting technology particularly extra pale  and bright wort and kettle colours are achieved
Pilsner Malz 2.5 - 4.0 Pilsner 100% made from the best domestic 2-row summer brewing barley
every other type of beer for brewing all pale beers
as base malt for special beers
Pale Ale Malz 5.5 - 7.5 suitable for all beers 100% produces excellent lager and ales
Wiener Malz 6.0 - 9.0 Exportbier 100% producing "golden beers" and promoting body
Münchner Malz I 12 - 18 dunkle Biere up to 100 % Underlines the typical character of the beer by flavour enhancement
Festbiere  Achieve a strong beer color
II 20 - 25 Starkbiere
Buchenrauch-Gerstenmalz 4.0 - 8.0 Rauchbiere up to 100 % gives the typical smoke flavour
Lagerbiere rounded beech smoke flavor with slight honey and vanilla notes
Eichenrauch-Weizenmalz 4.0 - 6.0 Weizenbiere up to 80 % made from quality wheat
Rauch-Weizenbiere fine oak smoke flavor with honey and vanilla notes 
Grätzer Bier
Weyermann product brochure, June 2014.


1 comment:

Ed said...

Seems perfectly clear to me.