Decoction Mashing

Brewing processes and methods. How to brew using extract, partial or all-grain. Tips and tricks.

Moderator: slothrob

Post Reply
Dr Strangebrew
Pale Ale
Pale Ale
Posts: 77
Joined: Tue May 13, 2003 7:01 pm
Location: Lincoln, NE, US

Decoction Mashing

Post by Dr Strangebrew »

I am planning on brewing a Maibock for this spring. I am interested on hearing from those of you who do it why you do it. I am also interested to hear from those of you who have tried it, but don't use a decoction mash habitually for German lagers.

I plan to use the following grain bill:

10 lbs Weissheimer Pilsener Malt
4 lbs Vienna
1 lb Crystal Malt 10L

I have used this pilsener malt before with a single temperature infushion mash and achieved 81% mash effeciency so I am not worried about conversion. I am just trying to determine if the extra effort to perform a decoction mash will result in a beer with a NOTICEABLY better malt profile. I suppose better is a vague term how about this. What are the benefits of a decoction mash and with the modern malting developments is decoction mashing neccessary to produce a accurate representation of German lagers?

Thanks,
Nate
Raydownunder
Pale Ale
Pale Ale
Posts: 52
Joined: Mon Jul 31, 2000 5:09 am
Location: Wollongong Australia
Contact:

Give it a go! But read below before you start.

Post by Raydownunder »

Hi all

Having had the last 18 months exploring decoction mashing I hope I can answer this question.

1. You can brew superb German or any beers using current well-modified malts from around the world with single infusion mashes.
2. Decoction mashing IF done correct will increase the malt character and improve efficiency.
3. With the current well-modified malts you have to be careful with decoction mashing. As I will explain through experience and chatting to those who know.

NEVER do an acid rest (54C) or there about with these malts as it will make your beer too thin and all the effort of your decoction will be destroyed.

Mash in at 64C for 60 minutes. Take out 30 to 40% of the thick mash with some wort and transfer to a 20L pot. (You should have your grains in the mush tun covered with some wort). Add heat slowly over 30 minutes till it reaches the boil. Boil the decoction for only 10 minutes (you need to be stirring the decoction most of the time so it does not burn the bottom of the pot). Then transfer this decoction back to your mash tun slowly with heaps of stirring.

Once back to the mash tun you should have a mash temperature of about 70C. Leave the mash at this Temperature for 30 minutes. Then run-off and sparge as normal.

IMPRTANT!
This is important with decoction mashes or any mashes that are constantly stirred.
To eliminate any astringency from your beer through Decoction mashing add 1/8th of a teaspoon (the size of a green pea) of sodium metabisulphite in your mash tun. It will not affect you beer in any way other than saving a days work.

Need any more questions please let me know?

Ray Mills
drudolph
Posts: 2
Joined: Fri Jan 02, 2004 11:22 pm

Decoction Mash

Post by drudolph »

I agree with Ray Mills assesment of decoction mashing and would add:

1. Allows you to raise mash temps without adding direct heat or boiling water (which can thin the mash). Great for those of us with modified cooler-type mash tuns.

2. For the mash out, I also do a second decoction with the thin portion of the mash (mash liquor) by boiling that until a hot break forms (about 15-20 minutes) and returning to the main mash. This denatures the enzymes, reduces viscosity for the sparge, and keeps some break material out of the kettle.

3. Decoction mashing does coagulate some proteins and reduces the amount that goes in the kettle. Down side is it can clog up the grain bed and lead to stuck sparge.

4. I have never added sodium metabisulfate and do not have problems with astringency (tannins that are oxidized while hot can cause this, and can cause premature staling). In fact, it could affect the hop character of your beer .. especially if it is a pilsner. Just be careful not to introduce too much air while stirring and pouring.

Hope it helps, and happy brewing!

Don Rudolph
Dr Strangebrew
Pale Ale
Pale Ale
Posts: 77
Joined: Tue May 13, 2003 7:01 pm
Location: Lincoln, NE, US

???

Post by Dr Strangebrew »

Thank you both for your replies. One last question. When I remove a portion of the mash to boil it do I take the grain with it?
Thanks again,
Nate
drudolph
Posts: 2
Joined: Fri Jan 02, 2004 11:22 pm

Answer

Post by drudolph »

Yes, remove mostly grains for the first decoction. I use a strainer or colander to leave liquid behind. On the second (make sure your mash is converted!), remove only liquid.
Post Reply