1st (and only) Decoction in 30 years.

[razz]

Hi all. Just a quick post to talk about doing a decoction, the first I've done. I had a typical brew day, that is, most things went to plan with the occasional **** up!
I'll keep it in point form to make it easy to read.
I brewed a NZ Pils, mostly Weyerman ale malt with a little acid malt, hopped with Pacifica 3.8% AA pellets. 30 minutes and steeped addition 60 minutes.
A double decoction method with dough in at 65 degrees, decoction to get to 71 degrees and a second decoction to get to 76 degrees.
I conditioned the malt (2% hot water sprayed onto malt and left for 20 minutes) and while I got more flour than normal it doughed in well with no dry balls.
I used Beersmith3 and it was very accurate. The 1st decoction was spot on and had the mash sitting right on 71 degrees for the 2nd rest.
The second decoction I decided to draw off liquid rather than grain and that left me a few degrees short of the mashout temp, no problem I thought as I had just denatured a fairly good amount of enzymes. Beersmith obviously calculates for grain decoctions at each stage. Lesson learned.
A small amount of Phos acid in the sparge water and I got pH 5.6 and 1.020 at final runnings. Happy with that.
Collected 57 litres with a higher than expected SG, 50 minute sparge. I've had clearer run off, but after 5-6 litres of vorlauf it wasn't getting any clearer. Not an issue.
Accidentally added the mineral additions in at start of boil 120 minutes instead of 60 minutes.
Boiled down to 45 litres with a final SG 1.060, predicted 1.050. Chilled with immersion coil after steeped hop addition.
I fitted a sight glass to the pump outlet to watch the run off to fermenter, I ran off the 42 litres that I needed but the last few litres was pretty cloudy.
MHB was in my head saying "keep that crap out of the fermenter"
I think in future I will adjust boil volume and finish with an extra 7-8 litres and just run clear wort into fermenter. Damn you sight glass!
Tank water through the immersion coil was 13 degrees and I finally pitched 34/70 dry yeast into 15 degree wort.
So, there you have it. I've had a good day and learned quite a lot.
Enjoy your Saturday night, I'm watching the Roosters V Rabbitos.

 

[MHB]

I've never had a problem with Cold break going to the fermenter - just Hot break!
Decoctions are interesting, had a bit of a play around with them a few years ago, made a mash tun with a 50mm butterfly valve in the bottom so I could dump heavy wort into a 5L jug sitting on a set of scales....
Lager malt is more suitable for decoction (well you get more out of it), I would try Weyermann Floor-malted Bohemian Pilsner if I were to do another decoction.
That's an IF, educational, interesting... but Oh so slow and with modern malt I don't think we see the returns on the time invested that brewers would have in the past.
At least not as much of a gain in either extraction efficiency or flavour as under modified malts would yield.
However, the best home brewed Pilsner I ever tasted was a triple decocted Pils/Hallertau so maybe I'll have to revisit it one day.
Pluck the roosters
Mark