The optimal gap size will depend on your grain type and volume of grains.
If brewing with a Grainfather Brewing System, we recommend starting at Gap Setting 5 for most pale malts and adjusting as necessary after your brew session. For more information about why it is important to get the crush right, see here.
Please see below or in your Grain Mill Instructions for a guide on general Gap Setting/Size recommendations:
| Gap Setting | Gap Size (mm) * | Recommended Grain ** |
|
1 2 3 |
0.8 0.85 0.95 |
Use for other grains and specialty malts that need a smaller gap, and brewing systems than can manage a finer crush, and more malt flour. |
| 4 | 1.1 |
Dark Malts (>450 EBC/150L): Black Patent, Carafa, Chocolate, Roasted Barley, etc. |
|
5 6 |
1.3 1.5 |
Non-Barley Malts: Millet, Rye, Wheat. Base Malts: American 2-Row, Munich, Pale Ale, Pilsen (pilsner), Vienna, etc. Large Size Continental and Heritage Malts: Koln (Kolsch) Golden Promise, Marie Otter, etc. Specialty Malts: Caramel Crystal, Biscuit, Brown, Golden Naked Oats, etc. |
|
7 8 9 10 |
1.7 1.85 1.95 2
|
Use for other specialty malts that need a wider gap, and brewing systems that require a high wort flow (a coarse crush). |
|
* This is an estimate, each mill may vary slightly. ** These are general guidelines, malt size and specifications varies by barley variety and malthouse. If you experience issues, increase the gap size and also, increase the speed setting to 6. Flaked grain and corn products are not recommended and could cause damage to the grain mill. |
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NOTE: Rolled and flaked adjuncts (e.g. oats, rice, corn) do not need to be crushed before brewing. We do not recommend crushing a mixture of grain that contains a high amount of these adjuncts.