Beer Forum

OK, so I decided to attempt a decoction mash since I have been brewing all grain for over 4 years now and have a firm grip on the normal mashing process.

Grain Bill:
6 lbs German Wheat Malt (2L)
5 lbs German Munich Malt (33L)

My first attempt was precluded by a some research and watching Braukaisers You Tube videos (thanks dude). I also watched the Northern Brewer video on decoction mashing. I proceeded with the knowledge I needed, but still had a few issues that brought me great strife.

My first problem is I seemed to run out of thick mash before I collected the extra mash that was recommended (Northern Brewer suggested 1qt thick mash per pound of grain) and I only collected about 9 or so quarts. My mash tun temp may have dropped during the decoction. When adding the boiled thick mash back to the mash tun my temps did not rise enough. I only hit 148F when I needed 154F. I decided to pull a gallon of thin mash and reboil to raise the temp...this only raised the temp by about 2 degrees, so I repeated with 2 gallons of thin mash. This time my temps came up to where I needed them after adding a gallon, so I started my saccharificaion rest and added the rest of the thin mash when the temp cooled to 154F.

The next problem was that during the ramping up and boiling of my thick mash I managed to scorch and burn some of the grist on the bottom of my kettle. I thought I was ramping up slow enough and the total time to reach a full boil was well over an hour at this stage. I have to admit that a few times during ramp up my thick mash boiled in the very center and I stirred it to even out the heat. I kept ramping up until I had a pretty constant 210F in the kettle and added it back to the main mash. I was stirring this thick mash nearly continually, but even still I seemed to have the hot spot in the center of my kettle and scorched the mash.

Another issue during my brew day was I forgot to do a saccharification rest on my decoc during ramp up.

I also did a thin mash decoc for my mash out rest.

Well, after all was said and done and my brew day was completed I decided to check my starting (post boil) gravity and taste the wort. This was when I really got discouraged because the burnt decoction mash really gave my wort an awful burnt flavor. After an epic 12 hour brew day I am left deciding whether or not I should dump this batch.

I plan on letting it finish fermenting and giving it another taste, but I'm already planning on re-brewing this same recipe next weekend and re-pitching the yeast from this failed excuse for a Dunkelweizen.

Does anyone know if the yeast from this "burnt" batch will pick up any flavors I might not want in my next batch? I would much rather just do another starter and pitch that than risk ruining a second batch of beer. Any recommendations for my next attpemt that might help me to avoid these issues is very welcome.

Does anyone have input or advice regarding the yeast and if it will pick up the burnt flavors and affect my next batch?

By all means be direct and call it like you see it if you wish to give me advice or criticism.

This was certainly a learning experience and I gained a lot of knowledge and understanding about the decoction mashing process. I can't say that I am turned off on or discouraged by the whole experience, but now that I realize how much extra work goes into doing a decoction, and the chances of scorching your wort, I might not be so quick to brew a batch that "requires" decoction mashing.

I don't have direct experience with 'burnt decoction yeast' but I do have a bit of experience rinsing/washing yeast. I have noticed that in a heavily hopped batch, not only do the residual oils effect the yeasts performance, but there does seem to be a lingering flavor from them as well. However we're talking oils in that instance. The cell walls are permeable, so I wouldn't be surprised if that flavor lingered, but to what extent I couldn't even begin to guess.

Sorry I can't be of more assistance.

Burnt flavors will fade over time... an early batch of the guy I learned homebrewing from, he ended up scorching his grain bag on the bottom of his kettle. They named it "Burnt Sock Ale"... he said while it was a straight drain pour initially, after months and months in the bottle, it was almost drinkable..

Ozwald wrote:...The cell walls are permeable, so I wouldn't be surprised if that flavor lingered, but to what extent I couldn't even begin to guess...

Thanks Ozwald, I guess it's better to just pitch a fresh yeast slant / starter than to risk the flavor carryover into my next batch. I am planning another attempt at this Dunkelweizen decoction, or maybe I will play it safe and brew my Cream Ale recipe.

I wonder how WLP300 would do on a porter recipe? That might cover up the burnt flavor if it did carry over.

spiderwrangler wrote:Burnt flavors will fade over time... an early batch of the guy I learned homebrewing from, he ended up scorching his grain bag on the bottom of his kettle. They named it "Burnt Sock Ale"... he said while it was a straight drain pour initially, after months and months in the bottle, it was almost drinkable..

LOL Spider Maybe I will take the time to bottle this batch and just hide it in a closet somewhere. I usually keg, but maybe this batch will go into bottles after it's carbonated.

So far I've decocted 4 batches . I'm no expert but here is my 2c .
When you pull your first amounts of grain . Have a helper stirr . During this moment never stop stirring . Then when you add back to main mash stirr . Wait 2 min then check temp . You might be checking hot /cold spots . If you have a way to heat mash do that to raise temp like normal . If you boil the thin part of the mash you might lock in the starches and not get full conversion . But I wouldn't worry too much . Finally don't sweat the small steps . It's still beer . You can also use the beer as a learning tool for others that are interested in decocting and what burnt grains taste like

I almost forgot . I use my 4 gal extract pot for decoction . That way if I do burn the grain I won't have to scrub the crap out of my boil kettle before I have to sparge . More mess less hassle

For a first decoction mash one needs two extra arms and two extra eyes. Eventually you will get to the point where you can get by with one extra eye and one extra arm. You can't reasonably expect to get it right the first time out. In fact when it comes to hitting temperatures it's not likely that you will ever get it exactly right so you must be prepared to make adjustments for over/under shoot. For undershoot direct heat is, IMO, the best choice because an infusion will dilute the mash too much if the required temperature correction is anything other than very small. For overshoot cold water is about the only thing you can do and while here too there will be dilution there isn't much you can do about it.

Scorching of the decoction is extremely common. The only solution for this that I have found is to heat with steam rather than direct heat but I recognize that steam isn't probably the most practical heat source for most home brewers.

The scorching problem can be ameliorated somewhat by adding some water to the decoction right after you pull it. The object in pulling a thick decoction isn't to have a thick decoction so much as it is to leave the majority of the enzymes in with the rest mash. An oatmeal like decoction will burn with direct heat even if kept in constant motion - it only takes a second's inattention.

As for the yeast picking up scorched flavor - I can't see it but who knows. If you are worried about that you could make up a little wort, pitch that with some of the yeast, let it ferment and then taste.

For getting scorched grain off the floor of the decoction vessel I found a putty knife very effective.