What is bock beer?

Only beer with an original extract above 15 percent may be called bok or bock in the Netherlands.

That rule is in Article 7g of the Warenwetbesluit Gereserveerde aanduidingen. It applies to every name of which bok or bock is a part, so herfstbok, lentebok and dubbelbock all fall under it.

Original extract is the amount of dissolved substances in the wort, before the yeast goes to work. The higher that number, the more sugar there is to ferment. For pilsner the same decree requires 11 to 13.5 percent, so a bock starts where a pilsner ends.

On colour, yeast type or alcohol percentage the law says nothing. A bock beer may be dark or blond, top- or bottom-fermenting.

Most bock beers are between 6 and 8 percent alcohol.

The style guidelines of the Beer Judge Certification Program give 6.3 to 7.2 percent for dunkles bock and 6.3 to 7.4 percent for helles bock. A doppelbock runs from 7 to 10 percent, an eisbock from 9 to 14 percent.

Dutch law sets a requirement on the original gravity and not on the alcohol percentage. How far a brewer lets fermentation go determines how much of that original gravity becomes alcohol and how much residual sweetness remains. Two bock beers with the same original gravity can therefore differ by a percent.

Een bok is dus stevig vergeleken met een pils. Verkoop en schenken zijn vanaf 18 jaar: NIX18.

The bock beer season begins in the Netherlands in late summer and runs on into winter.

The fixed marker is the Nationale Bokbierdag in Zutphen. It has existed since 1995 and the next edition falls on Sunday 11 October 2026. In the weeks around it, the Dutch breweries release their autumn bock.

The bock also has a spring version. Helles bock, also called maibock, belongs to spring and the month of May according to the style guidelines. Autumn bock and spring bock are therefore the same type of beer at a different time of year.

Herfstbok is dark and appears in the autumn, lentebok is lighter in colour and appears in the spring, and dubbelbok is the heavier form.

Colour comes from the malt and not from strength. For dunkles bock, the dark autumn form, the style guidelines give 6.3 to 7.2 percent alcohol at a colour of 14 to 22 SRM. For helles bock it is 6.3 to 7.4 percent at 6 to 9 SRM.

A doppelbock or double bock is higher, at 7 to 10 percent. That style comes from München, where the monks of the Order of St Francis of Paola brewed the beer around 1700 and drank it during Lent.

The strongest form is the eisbock, at 9 to 14 percent. A doppelbock is frozen and the ice removed, leaving the flavour and alcohol concentrated in what remains.

The name goes back to Einbeck, a North German town that was a major brewing centre in the Hanseatic era.

Einbecker beer was exported to many cities from the fourteenth to the seventeenth century. In Munich the style was brewed in imitation in the seventeenth century, and there the beer got the short name it still carries today.

Bock also means ram or billy goat in German. That is why many labels show a goat, although the animal has nothing to do with the recipe.

In Dutch, both bok and bock are in common use. For the law the spelling makes no difference, because article 7g names both forms.