Malt Glossary: What Is Mashing? Sparging, EBC & Diastatic Power Explained

Malt terminology — EBC colour, diastatic power, mashing, sparging — covers both the malt itself and the process of turning it into wort. This glossary explains both. For a full side-by-side comparison of malts by colour and type, see our Malt Selector.

What Is Mashing?

Mashing is steeping crushed malt in hot water (typically 63–69°C) so the grain's natural enzymes convert starches into fermentable sugars. This happens over 60–90 minutes and produces a sugary liquid called wort. It's the step that separates all-grain brewing from extract or kit brewing, where this conversion has already been done for you at the maltings or extract plant.

What Is Sparging?

Sparging is rinsing the mashed grain bed with additional hot water after mashing, to wash out the remaining sugars that are still trapped in and around the grain husks. Done well, it maximises your extract efficiency (how much sugar you actually capture) without over-diluting the wort or extracting harsh tannins from the husks — which is why sparge water temperature (usually kept under 78°C) matters.

EBC (Colour)

EBC (European Brewery Convention) is the scale used in the UK and Europe to measure malt and beer colour — low numbers are pale (2–5 EBC for base malts), rising through amber and crystal malts (20–150 EBC), up to very dark roasted malts (900+ EBC for black malt). It's a straightforward way to estimate how much colour a given weight of malt will contribute to your batch.

Lovibond / SRM

Lovibond (and the related SRM scale) is the US equivalent of EBC for describing malt and beer colour. Conversion is roughly EBC = SRM × 1.97, so a malt described as ‘60L’ (60°Lovibond) is roughly 120 EBC. Most UK maltsters publish EBC; most US recipes and software use Lovibond/SRM — worth knowing when following recipes from either side of the Atlantic.

Diastatic Power

Diastatic power measures how much enzyme content a malt has available to convert starch into sugar during mashing. Base malts (Maris Otter, Pale Ale malt, Pilsner malt) have high diastatic power and can convert their own starch plus a proportion of added unmalted grain or specialty malt. Crystal, chocolate, black and other heavily kilned or roasted malts have little to none — their starches were already converted or destroyed during production, so they contribute flavour and colour but can't help convert other grains.

Base Malt vs. Specialty Malt

Base malts (Maris Otter, Golden Promise, Pilsner/Lager malt) make up the bulk of a grain bill and provide most of the fermentable sugar. Specialty malts (crystal, chocolate, black, amber, biscuit) are used in smaller amounts to add colour, flavour and body — they're rarely more than 5–15% of a recipe, since they contribute little fermentable extract on their own.

Crystal Malt vs. Caramel Malt

These names are largely interchangeable in UK and European brewing — both refer to malt that's been stewed to convert its starch to sugar, then kiln-dried so the sugar crystallises inside the grain. ‘Crystal’ is more common in the UK; ‘caramel’ (often abbreviated CaraXX, e.g. CaraMunich) is more common with German/Belgian maltsters. The process and result are the same family of malt.

Kilning

Kilning is the heat-drying step after malting (germination) that stops the grain sprouting further and develops its colour and flavour. Light kilning gives pale base malts; progressively higher kilning temperatures give amber, brown, and eventually black malts — with diastatic power dropping off as kilning intensity rises.

Husk

The husk is the grain's outer shell, left largely intact through malting and crushing. It acts as a natural filter bed during mashing and lautering/sparging, but can release harsh, astringent tannins if oversteeped or sparged with water that's too hot or too alkaline — part of why sparge temperature control matters.

Malt Modification

Modification refers to how fully a grain's internal starches and proteins were broken down during malting. ‘Well-modified’ malts (most modern base malts, including Maris Otter) convert easily with a simple single-temperature mash. Under-modified malts (some traditional Continental base malts) sometimes benefit from a multi-step mash to fully convert.

Frequently Asked Questions

What temperature should I mash at?

63–69°C is the typical range — lower for a drier, more fermentable wort, higher for a fuller-bodied, less fermentable one. 66–67°C is a common all-purpose starting point.

Why does sparge water temperature matter?

Sparging too hot (above roughly 78°C) risks extracting harsh tannins from the grain husks, giving an astringent, papery character to the finished beer.

Can I substitute crystal malt for caramel malt in a recipe?

Generally yes, matching by EBC/Lovibond colour — they're the same style of malt under different regional names. Check the specific EBC rather than relying on the name alone.

Do I need to mash crystal or chocolate malt?

No — these have already been converted during production and can simply be steeped, which is why they work in extract and kit brewing as well as all-grain.