Brewery tours

Find one near you at www.german-breweries.com or www.beerme.com.  I can vouch for the Welde tour in Schwetzingen (near Heidelberg).  It was reasonably kid friendly and every second tour is in English.  "When should we arrive" is a bit hard to pin down but there's usually not more than a half hour wait (enough to let the tour starting just ahead of you get going and out of your way).   The free drinks at the end include a good selection of sodas and plenty of pretzels. The beer garten and free sample room are on different floors so you can't spend the afternoon eating while drinking free beer.  The Schwetzingen gardens are a short drive away and absolutely gorgeous before everything dies off for the winter.