Wood-Fired Steam Oven @museum.de

Mmm, there’s always that wonderful early morning smell of fresh rolls in here!

Yes, all thanks to our good old steam oven! Which we've been firing up every morning for almost 40 years... actually, more like every night, to make sure the rolls are ready first thing. Four decades ago, when the oven was installed in here, it was the best that money could buy, and state of the art, too. Old Hildebrand, who ran the place at the time, spared no expense! But now... the old oven’s a bit outdated. And the steam ovens of yesteryear really aren’t that fashionable any more.

Why is it called a steam oven? Is there steam inside the oven? To stop the cake mixture drying out?

Yes and no.

What do you mean, yes and no?

Yes, you are right: the cake mixture mustn’t be allowed to dry out as it’s baking.

And no, the steam – at least the steam that gives the oven its name – is not inside the oven, but all around it.

All around it?

Yes. The oven is heated from the back, and the heat in the firing chamber is transferred to long pipes that are filled with water and tightly sealed. And those pipes extend all the way to the baking chamber.

And the water in the pipes gets hot, evaporates and heats the baking chamber.

Quite right! And when the water cools down, it condenses inside the pipes and runs back to the other end, where it’s heated up again...

...and turns into steam. I understand. But those pipes must be under a lot of pressure if they have steaming hot water constantly sloshing around inside them.

Indeed. Which is why steam ovens have occasionally been known to explode.

Oh, my goodness! Really?

Yes, but ours hasn’t. At least not yet. But... it's been in use now since 1892, so for, let me see, nearly 50 years. At some point, we’ll need a new oven. Maybe one of those nice electric ones they make now... one made by Neff. Brilliant appliances.

Except... how are we going to get a big oven like that in here? Certainly not through the narrow passage and the courtyard. You'd probably have to break open the back wall and bring it in through there... But that will be up to your aunt to decide, in any case. She's the manager here.

But why don’t you go and see if you can find the old oven’s firing chamber? Because though the steam oven is fired up every morning, it doesn’t happen here in the bakehouse. Which is just as well, because otherwise we'd have coal and ashes here in this small room, where absolute cleanliness is essential. So, Gardi, where do you think the oven might be heated from?

Hmm... I think... I have an idea!