The Brewer's Analyst: A Systematic Handbook of Analysis Relating to Brewing and Malting, Giving ... by R. Douglas Bailey

Author:R. Douglas Bailey
Language: eng
Format: epub
Publisher: D. Van Nostrand company , 1907
Published: 1907-03-25T05:00:00+00:00

Per cent on malt Matters soluhle in cold water 16*06

Per cent on malt.

Soluhle albuminoids . .2*66

Mineral matter or ash . .1*08

Acidity 0*13

3*87

12*19

The ready-formed soluble carbohydrates on 100 parts of malt^ 12'19, so that 10 grams of malt contain 1*21 to correspond with 100 cc. of wort.

7. Soluble ProteidS or Albuminoids.— These are determined as in malt analysis, under Soluble Albuminoids.

10 c.c. of the 10 per cent, cold-water extract evaporated to dryness in a boiling flask ; 10 c.c. of strong sulphuric acid and 5

^ This figure, it will be noticed, is rather low.

grams of potassic sulphate added, the contents warmed and then

boiled until the solution is clear; then added to a distilling flask

with about 100 c.c. distilled water, about 40 c.c. sodic hydrate

added together with a few pieces of pumice, the flask connected

with the distilling apparatus and the contents distilled, the

N distillate being collected in a flask containing 50 c.c. — sulphuric

acid.

100 c.c. of the distillate having been collected, the acidity is tested:—

N N

Example. —50 c.c. —- acid required 44 c.c. — alkali to effect

neutralisation.

50 - 44 = 60 c.c X 0007 = -00420 x 10 = 04200 x 6-33 = -26 albuminoids in 100 c.c. of cold-water extract.

8. Specific Rotatory Power of Cold water Extract—A

small quantity of the extract is boiled and then cooled to 68* F. (20" C). A 2 decimetre tube is then filled with the same, placed in the polarimeter, and a reading taken. The reading, divided by 2, gives the reading of a 1-decimetre tube.

Ezample.-'Optioitj in 2-decimetre tube - 0*60". 0*60 -r 2 = 0*30*.

9. Cupric Oxide Reducingr Power of Cold water Extract.

—Determined as with the 10 per cent, hot mash wort (p. 213).

Example, —CuO obtained = -282 amount in 20 c.c. -282 x 5 = 1*41 gram on 100 c.c. of 10 per cent, malt extract to correspond with 100 parts of wort.

10. Mineral Matter or Ash. —Determined as per Malt Analysis. 50 c.c. of the 10 per cent, cold-water extract evaporated to dryness in a tared platinum dish, after sulphating; then ignited to ash, cooled, and weighed : —

Weight of platinum dish -t- ash . 16*394

Weight of platinum dish .... 16*340

•054 •054 X 2 = '108 per cent, on wort.

We now deduct the figures obtained from experiments with, our cold-water extract from the corresponding determinations of our hot wort, thereby arriving at figures due entirely to stcurch products. Our results are therefore worked out as follows:—

«T . Cold-water Conversion Products ^ ^^ Extract due to Starch.

Cupric oxide reducing power 7*35 - 1*41 = 5*94

Specific rotatory power . 900 - 0*30 = 8*70

METHODS OF ANALYSIS

217

Each gram of cuprio oxide, according to Fehling^B factor, equals '7435 gram of maltose; we therefore obtain the amount of maltose in the wort by multiplying the cupric oxide obtained by this factor.

5'94 (CuO due to starch products) x 7435 » 4*44 maltose in the wort expressed in percentage on the wort.

The specific rotatory power of 100 grams of maltose, when observed in a 1-decimetre tube, is [ajog-w—^^^*^'> therefore 1 gram = 1*359'*.

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