Decoction at a Full Sized Brewery

I've become a true believer in decoction mashing for traditional German beers. But I am not here to restart that debate.

I am wondering how a full sized brewery does a decoction. I admit this is a bit embarrassing as I worked at a German brewery about 9 years ago for a summer. In my defense I only worked in the brew house for 2 days, then spent the rest of the time cleaning, bottling, and delivering (since most of the bottles were reused bottles, one job was actually watching the cleaned bottles go by to make sure they were not broken or dirty, you were only allowed to do this job in 30 minute shifts).

I don't remember them pulling any of the mashed grain out. My thinking is maybe what you do is actually pull most of the liquid out and then boil all of the grain before mixing everything back together? But would the pulled liquid conserve enough enzymes to convert the remaining starches?

Honestly don't remember and can't come up with anything much better

There are basically two kettles/mash tuns. The mash is started in one. After a rest the more liquid part is pumped over to the other kettle and continued to rest while the thick part boils. The thin part is pumped back for the next rest and so on until mash out when only the thin part is boiled. Most of the enzymes are in the more liquid part. That's why it's not boiled until the end.

Malticulous said:

There are basically two kettles/mash tuns. The mash is started in one. After a rest the more liquid part is pumped over to the other kettle and continued to rest while the thick part boils. The thin part is pumped back for the next rest and so on until mash out when only the thin part is boiled. Most of the enzymes are in the more liquid part. That's why it's not boiled until the end.

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So they are boiling all of the grain then? I remember there being a false bottom in only one of the kettles along with a mixer (using chains).

I've only seen one and I'm sure they are not all the same. Your right it only needs one mash tun but both need to be able to boil.

gometz said:

I don't remember them pulling any of the mashed grain out. My thinking is maybe what you do is actually pull most of the liquid out and then boil all of the grain before mixing everything back together? But would the pulled liquid conserve enough enzymes to convert the remaining starches?

Honestly don't remember and can't come up with anything much better

Click to expand...

This sounds like the decoction schedule I do. Look up the "Schmitz Process". I do it all in one kettle with a stainless steel mesh basket and drain most liquid into a cooler after my first beta rest then boil all the grains in the basket for 30 minutes, cool it down then add the liquid back to the kettle/basket for a second alpha rest. I don't mash out or sparge, just lift out the basket and let it drain then boil.