🥃 Malting
Turning grain into malt: barley is soaked, germinated for 4–6 days and dried; the malt enzymes then convert the mash's starch into sugars for whisky and beer.
Malting is the conversion of grain, most often barley, into malt: the grain is soaked, allowed to germinate and dried with hot air. During germination the grain develops enzymes which later convert starch into sugars in the mash, and yeast ferments them. Without malting there would be no malt whisky and no most beers.
Steeping. According to the Maltsters' Association of Great Britain, barley is first dried to below 14% moisture and rests for at least six weeks until the embryo leaves dormancy. Then two or three immersions in water, with air breaks over 2–3 days, raise the moisture to about 46%; Difford's Guide gives a water temperature of around 16 °C.
Germination lasts 4–6 days. The grain, now called green malt, is turned so that the rootlets do not tangle and overheat. The oldest method is floor malting, in beds 15–50 cm deep on stone floors; in Scotland only seven distilleries have their own malting floors: Laphroaig, Bowmore, Highland Park, Kilchoman, The Balvenie, BenRiach and Springbank. The rest buy malt from industrial maltings with drums.
Kilning. A kiln lowers the moisture to 3–6% in 24–48 hours: first air at about 60 °C, then 70–90 °C. If peat is burned under the grain, the malt absorbs phenolic smoke and the whisky becomes peaty — from light (1–5 ppm of phenols) to very heavy (over 50 ppm). At the end the rootlets, which go to animal feed, are separated from the malt.
Why it matters to you. The word «malt» on a label says only about the raw material and how starch is turned into sugar, not about the quality or health benefit of the drink. Whisky made from any malt contains the same ethanol. The WHO reminds us that there is no safe level of alcohol consumption.
Facts
| Raw material | barley (less often other cereals), water; for peated malt, peat in the kiln |
|---|
How it connects to Spirits
🥃 Malting → kind of → ⚗️ How spirits are made → kind of → 🥃 Spirits
Links
- Next step
- 🍷 Alcoholic fermentation, 🥃 Peated whisky, 🥃 Single Malt Scotch Whisky, 🥃 Laphroaig, 🥃 Bowmore, 🥃 Highland Park, 🥃 Kilchoman, 🥃 The Balvenie, 🥃 BenRiach, 🥃 Springbank
- What it affects
- 🍷 Alcohol and health
- Part of
- ⚗️ How spirits are made
- Similar and different
- 🥃 Barley and malt in whisky, 🥃 Maltster, 🥃 Maltster, 🥃 Mashing, 🥃 Mashing
Frequently asked questions
Is it true that all Scottish distilleries malt their own barley?
No. According to Difford's Guide, only seven distilleries have their own malting floors; most buy ready malt from maltings.
Why is barley germinated?
During germination the grain develops enzymes which convert starch into sugars in the mash; without them the yeast would have nothing to ferment.
How long does malting take?
Steeping 2–3 days, germination 4–6 days, kilning 24–48 hours; on floor malting the whole cycle takes about a week or more.
Where does the smoky aroma in malt come from?
From peat burned in the kiln: the malt absorbs phenolic compounds, measured in ppm — from 1–5 in light malts to over 50 in very peaty ones.
What is green malt?
Germinated, still moist grain before kilning; the kiln stops germination and makes the malt suitable for storage.
What to read next
- 🍷 Alcohol and health — Alcohol in any drink is harmful in large amounts, and the risks grow with the quantity.
- 🥃 Barley and malt in whisky — Malted barley is the base of whisky: malt enzymes convert starch in the mash, and EU whisky is distilled below 94.8% vol.
- 🥃 Single Malt Scotch Whisky — Scotch from a single distillery: only malted barley, water and copper pot stills; at least 3 years in oak, 40% vol. or more.
- 🍷 Alcoholic fermentation — Yeast eats the sugar in the must and releases alcohol and carbon dioxide.
- 🥃 Peated whisky — Whisky with a smoky aroma from malt dried over a peat fire; it is a style, not a separate legal category.
Similar
🥃 Maltster · 🥃 Aqua vitae · 🥃 Ethyl alcohol of agricultural origin · 🥃 Double distillation · 🥃 Heads, hearts, tails · 🥃 Triple distillation
⚠️ Spirit drinks contain alcohol and are for adults only. Alcohol harms health. Do not drink during pregnancy or before driving; check the label for ingredients and possible allergens.
Sources
- Difford's Guide: Single Malt Scotch Whisky Production — Malting (steeping 12 % → 43–46 % moisture at c. 16 °C; germination 4–5 days, floor malting c. 7 days, beds 15–50 cm; kilning 24–48 h, 60 °C then 70–90 °C, to 3.5–6.5 %; peat levels in ppm phenols; Saladin boxes and drums; seven distilleries with floor maltings — Balvenie, BenRiach, Bowmore, Highland Park, Kilchoman, Laphroaig, Springbank; UK c. 1.5 Mt malt a year from seven large and seven smaller maltsters, distillers 48 %, brewers 40 %; maltsters buy c. one third of the UK barley crop)
- Maltsters' Association of Great Britain (MAGB): How Malt is Made — drying below 14 %, dormancy c. 6 weeks, steeping 2–3 immersions over 2–3 days to c. 46 %, germination 4–6 days, kilning to 3–6 %, deculming (rootlets to animal feed)
- Gazetteer for Scotland: Port Ellen Maltings — Diageo; industrial production from 1974; supplies most of Islay's nine distilleries and Isle of Jura; barley kilned over peat from Castlehill Moss, up to 2,000 t of peat a year
- WHO/Europe: No level of alcohol consumption is safe for our health (04.01.2023)