Extract from Adjuncts

Discussion points on unmalted cereals & copper sugars

General Considerations

Cereal adjuncts may be used at mashing; sugars or syrups may be added to the copper. Which is selected depends on brewing facilities, e.g. milling and mashing equipment and the ratio mashing to fermentation capacity.

With unmalted cereals consideration should be given to the species used. the character of the starch and whether pregelatinisation is required. The character and degradability of cell walls and whether the material is so finely ground as to hinder wort-separation must also be taken into account. Unmalted cereals contribute virtually no amino-nitrogen to wort but some can provide valuable foam active materials. The proportions of individual carbohydrates from unmalted cereals are broadly the same as from malt.

Malt extracts are traditional, but not essential, ingredients for brewing cask conditioned beers. They are a source of both carbohydrates and nitrogenous components and can be used to extend brewhouse capacity. Extracts made from malt with a high diastatic power and processed to preserve this may be used with advantage during mashing, particularly when high proportions of unmalted cereals are employed.

Copper sugars can be used to make mall-wort more fermentable. They contribute no nitrogen and. by altering the balance of carbohydrate to nitrogenous nutrients, affect beer flavour.

Syrups added to the copper again contribute no nitrogen to wort but quality can be specified either to increase or not to alter wort termer-liability

The specification of mall must lake account of the adjuncts employed so as to provide adequate carbohydrate fermentability and sufficient of the amino acids In wort.

Range of Values

Analytical values of unmalted cereals and of copper sugars are given in Table 5.

Operational Protocols

Cereal Adjuncts
Maize and rice must be degermed to remove fatty substances and should be pregelatinized (by flaking after mild steam treatment or micronising) just sufficiently to make them extractable at mash tun temperatures.

For wheat and barley adjuncts conversion in the mash tun is enhanced by mild cooking (torrefied, micronised or flaked products) or fine milling (wheat flour). Processing should be optimised to give minimum wort viscosity.

Copper Syrups
These should have the specified fermentability and a high enough content of solids to avoid microbial spoilage.

Condensation in storage vessels should be avoided to ensure microbiological stability and suitable cleaning procedures of storage vessels are necessary.

When mashing cereal ad.unc.s attention must be given to milling torrefied and pelleted products and to the appropriate mashing conditions.

Measurement Protocols

Wheat and barley flours and gelatinised flakes are analysed by the Institute of Brewing Recommended Method 4.1
Viscosily of cereal adjunct extract; wort is produced by the Institute of Brewing Recommended Methods 1977 and its viscosity is measured by the Recommended Method 8.2.

Sugars, syrups and caramels are analysed by the Institute of Brewing Recommended Method 5
Fermenlability of sugars, syrups and caramels is measured by the Institute of Brewing Recommended Method 7.1

 

Typical Ranges of Values for Malt Specifications

Characteristic Range Tolerance
Hot Water Extract (° per kg dry basis) Min 302 (High TN Malt, ca 175 mgs/ltr) to 312 (Low TN Malt ca 140 mgs/ltr) -4
Moisture (%) 2·7 – 3·3 +0·2
Colour (° EBC) 4 – 6 ±1
Total Nitrogen, TN (% dry basis) 1·45 – 1·75 + 0·03 (Low TN) + 0·05 (High TN)
Soluble Nitrogen Ratio 38 – 40 ±2
Free Amino Nitrogen (mgs/ltr @ 1040 gravity) 140 – 175* ±10 (Low TN) to ±15 (High TN)
Screenings, < 2·2 mm, % 1·5 – 2·0 +0·5
Corns > 2·5 mm, % 93 – 95 dependent upon variety and season -3
Ungerminated grains, % Target 0, dependent upon season +2
Cold Water Extract, % 18 – 19 ±1·5
Diastatic Power (° IoB) 35 (Low TN) to 55 (High TN) ±7 (Low TN) to ±12 (High TN)

Precise specifications, which should be balanced, will be agreed between supplier and customer. It is important that analyses are consistent between batches.
* As measured in laboratory worts which, because of factors such as mash thickness, contain less FAN than do the brewery worts. These values are consistent with a FAN content of 160 – 190 mgs/ltr in the brewery wort.