Decoction Woes

[Hopsta]

I brewed a belgian blonde today using wyermann bohemian pilsner malt and some wheat malt. I did a bit of research here on the bohemian pilsner malt and decided it would probably be best if i did a decoction. So i thought as its my first time (and only my 4th AG brew) i'd just do a single decoction. Following beersmiths instructions i pulled 7lts of grist and was supposed to let it rest at 70*c for 15mins but i stuffed up and rested it at 80*c for 15mins then boiled it as per instructions.

What effect will the the higher decoction rest temps have on the final product?

I also noticed a thick grey layer of gunk on top of the grain bed in my mash tun, is this just the extra protiens because bo pils is not a highly modified malt?

Another thing i noticed was my at the end of mash time the PH was high between 5.8-5.9 usually its down around 5.5? Maybe i shouldn't have skipped the mash out step, it just took so long to do the decoction i didnt think id need to bother?

Anyway the decotion added an extra 50mins to my brewday and it is a lot of stuffing around trying to get temps right etc, i use an igloo mash tun, im glad i had my immersion element without it i'd be stuffed.

The run off from the sparge was really clear so i shouldnt end up with a cloudy brew, i hope not anyway, thats the only reason i did the decoction in the first place.

So next time i need to use bo pils or any other "low modified" (if thats the term?) malt i think i'll try a step mash instead.

Cheers,
Hopsta

 

[DJR]

If you were mashing first-off at normal sacc temperatures, the rest being at 80C won't have made much difference. Most of the saccarification has already happened in the main mash, and will complete in the 2nd mash after you return and mix back. The rest at 70C just lets alpha-amylase do its job, but that will happen anyway in the main mash when you return it (and it will convert the extra starch released from the husk by boiling) so it's not really that necessary. As long as you rested long enough afterwards then it won't matter.

The Bo Pils is modified enough for a single or step rest, after my experiment with double decoction (53-66-72) i don't know if i'd bother doing it again. I'd just add some carahell and melanoidin malt to the grist and do a single infusion or 65-72 step rest.

Gunk may well have been proteins, the bo pils does benefit from a slight protein rest. I don't think the decoction will do much for clarity to be honest, with modern malts mashed correctly you won't experience much chill haze, and if you do, just include a protein rest as part of your schedule.

 

[Hopsta]

If you were mashing first-off at normal sacc temperatures, the rest being at 80C won't have made much difference. Most of the saccarification has already happened in the main mash, and will complete in the 2nd mash after you return and mix back. The rest at 70C just lets alpha-amylase do its job, but that will happen anyway in the main mash when you return it (and it will convert the extra starch released from the husk by boiling) so it's not really that necessary. As long as you rested long enough afterwards then it won't matter.

The Bo Pils is modified enough for a single or step rest, after my experiment with double decoction (53-66-72) i don't know if i'd bother doing it again. I'd just add some carahell and melanoidin malt to the grist and do a single infusion or 65-72 step rest.

Gunk may well have been proteins, the bo pils does benefit from a slight protein rest. I don't think the decoction will do much for clarity to be honest, with modern malts mashed correctly you won't experience much chill haze, and if you do, just include a protein rest as part of your schedule.

Yeh firstly i gave it a protien rest for 35mins at 50*C then i went through my decoction and added it back to the mash tun and rested it at 68*c for 45mins. Im looking forward to the final product should go down well in the warmer weather. :chug:

 

[Ray_Mills]

Hi
For your 4th Mash to jump into decotions you will have a million questions as your jumping into the very, very dark side.
I have posted this many times. with today's well modified malts it's really just adding an extra 2 hours a day to your brew day without much difference.
If you need to do a decoction just be carefull with the amount of grains you pull out to boil. Too much and your beer will be too thin.
You also really need to know what your brewhouse efficency is to make a Decoction work for you. When you do you can add the % increase to your recipe formulation, if you dont it will be way off your FG mark.
My mash efficency is 65% and with a single decoction it goes up to 75%.
I have not bothered with decoction mash's for some time as the extra hours involved really dont add up to much in the finall product.
Cheers
Ray

 

[Hopsta]

Thanks for the tips Ray. All valid points, i dont know what my exact brewhouse efficiency is and i was way off my FG mark! I think i'll leave decoctions till i know my brewery a bit better.

Cheers,
Hopsta

 

[Tony]

I only decoction mash beers i want to have a really full malty flavor.

It works well in wheat beers IMO and euro amber lagers but as ray said...... it really isnt necessary.

My efficiency is usually about 75% but goes up to 83 - 86% with a double decoction at 52, 66 and 76.

One thing i have found is that you dont need to mash as high temp to get a ballanced ber when doing a decoction mash because the grain is raised through the higher end of the temps a couple of times and provides the less firmentable dextrins that add body to the beer.

If u was doing a decoction mash say for an octoberfest type beer i would hold the sac rest at 65 to 66 as aposed to the 67 - 68 deg i would use for a single infusion mash.

hope this helps a bit

cheers

Edit:

One thing i forgot to add....... make sure your decoction is mainly grain with only just enough liquor to keep the grain fluid and sitrable. You are boiling the grain to break it down, not boiling the liquor.

The liquor you leave in the mash ton holds most of the enzymes and boiling too much of it will kill to many.

Here is a pic of my decoction boil from my pics in the gallery.

http://www.aussiehomebrewer.com/forum/inde...=si&img=505

cheers again B)