General Considerations
- The extent of malt milling is of crucial importance in brewing with regard to the efficiency of mashing and extract yield.
- There is generally no preferred method of milling for producing cask conditioned beer, providing that cloudy worts are avoided.
- Mill settings (ie. gaps between rollers) will be influenced by the corn size of the malt.
- The optimum particle size of malt grist depends on the mashing and wort separation system employed.
Range of Values – Typical values for the sieve analysis of grists used in different systems are as follows:
| Sieve mesh size (mm) | Mash Tun | Lauter Tun | Mash Filter |
| 1.3 |
53 | 27 | 9 |
| 1.0 | 14 | 12 | 4 |
| 0.6 | 16 | 28 | 9 |
| 0.25 |
6 | 15 | 28 |
| 0.15 | 3 | 4 | 6 |
| Flour |
8 | 15 | 14 |
Values represent the percentage of the grist retained on each sieve. A high proportion of husk is retained on the sieve of mesh size 1.3 mm.
Operational Protocols
- Sieve analysis should be carried out on samples of grist at least every 7 days. Check sieves for wear after approximately 500 analyses.
- The gaps between the rollers of mills should be checked at several points across the rollers when there are changes in grist analyses or mash tun performance. Replace or regrind worn sets of rollers.
Measurement Protocols
- A set of feeler gauges, range 0·25 – 1·75 mm (10 – 70 thousandths of an inch), is required for checking mill settings.
- Suitable sieves for grist analysis are available from Endecotts Ltd., 9 Lombard Road, Wimbledon, London, London, SW19 3TZ