Tuesday, February 9, 2016

Post-Fermentation Malt-Infused Porter

Tried five different roasted grains I had on hand.Why can’t beer just taste like beer anymore? Maple beer, passion fruit beer, elderflower beer... even new hop varieties are marketed as smelling like "coffee" and "garlic." What about a beer flavored with malt? Sure the Reinheitsgebot was an artificial constraint on the ingredients available to German brewers, but it focused their creativity on process (think: decoction, acidulated malt, first wort hopping).

With the ever increasing prevalence of weird-ingredient beers, American brewers (both craft and home) are overlooking the possibilities that weird process provides! Whether that is dry hopping before fermentation, concentrated Maillard-intensifying boil, or adding malt after fermentation (which is what I'm investigating with this post)!

The second filtration was likely unnecessary, but couldn't hurt.The concept for this porter was to age it for six months (while the other half was on tap), and then add cold-extracted dark grain to refresh the dark malt flavor and aroma. I've used cold-extracted dark grains before, but only before fermentation (like Dark Saison IV). Over the years I've drank a few stouts and porters (fresh Deschutes Abyss comes to mind) that have exhibited a hint of dough-in: that wonderful combination of fresh coffee and bready malt. That's what I wanted to accentuate. While not as sensitive as hop compounds, malt aromatics are driven off by the boil and fermentation and muted and muddled by age and oxidation. This isn’t always a bad thing, but it can be boring when that is what all malt goes through on the way to the glass!

The base for this experiment was the “plain” half of the chocolate-butternut squash porter that I brewed in early August. It had some roastiness, but after five months in the keg it was beginning to show its age, too dark-fruit forward. Dosing into a glass let me play with different rates and malt combinations without risking the whole batch. After testing a variety of dark malts in small scale infusion I settled on equal parts Weyermann Carafa Special II and Chocolate Rye. Both are husk-free, and provide a softer flavor contribution than black malt and roasted barley.

Paper filter after it was done with the extract.To make the extract for the full-batch infusion I ran the grains (2.5 oz each) through my Barley Crusher. While you can use a blade-style coffee grinder for dark malts, the fine particulate makes the spent grain sludge difficult to separate from the liquid. I combined the grain with 48 oz of filtered water in a sanitized growler, shaking occasionally to aid extraction. After 10 hours I decanted the liquid through a mesh coffee filter to remove large pieces of grain that hadn't settled. I then passed it through a paper filter to remove any dust (stouts and porters often taste better after roasted particulate is allowed to drop). Despite being a second pass this still took about 30 minutes.

I pasteurized the resulting inky black concentrate at 170F for a few minutes. While I doubt it would have caused a microbial issue going into cold/fermented beer, the extra effort was worth the peace of mind. Heating the extract also helps to reduce the amount of dissolved oxygen, although not as much as boiling would have. After cooling, I did another taste test to dial in my ideal ratio, and then dosed 23 oz directly into the depressurized mostly-full keg. This technique might also benefit from combination with water adjustments, but I didn't find that necessary flavor-wise (beers on nitro often benefit from slightly lower pH to replace the absent carbonic acid).

No idea what this glass is intended for, $.79 at Goodwill.ReMalted Porter

Appearance – Doesn’t look much darker than it was prior to the cold extraction, but when held at an angle to the light it is less translucent (still transparent, but brown rather than red right at the edge). Nice big tan head, a bit voluminous though, needed to settle and top-off to get a full pour.

Smell – Not quite brew-day morning, but much fresher grainy-roasty flavor than the beer was prior to the transfusion. Still has some dark fruit behind the coffee and roasted grain. On the upper-end of mocha for a porter. No hop aroma.

Taste – Roast is mellower on the palate than it was in the nose. Smooth cold brewed coffee, minimal roasted bitterness. Hops were never prominent, but by now they add just a slight bitter edge. Smooth, although a bit dry for my tastes. Fermentation seems clean, no noticeable off-flavors.

Mouthfeel – Not quite as full as I prefer for a cold-weather rye porter, although the creamy head helps with that body while it lasts. Low carbonation after running through the stout faucet. Amazing how much mouthfeel the butternut squash added to the other half!

Drinkability & Notes – This method breathes malty freshness into an aged beer, the malt equivalent of a hop tea. Adding more dark malt after fermentation certainly improved this beer, but at this rate it doesn’t provide a showcase character. It would be interesting to taste a dark beer with all of the roasted grain added like this! It could also be an easy way to make a split batch without having to divide the wort pre-boil. You could even try a shorter/hotter extraction if you wanted to see how that changes the roast impression. Lots of options, and certainly not the last of my attempts to use traditional ingredients in new ways!


Taylor said...

Do you have a preferred method for adding roasted grains to a recipe? E.g. For the entirety of the mash, during vorlauf, cold steeping and adding post mash, cold steeping and adding after fermentation, etc. I understand it may depend on what you're desired finished flavor profile is, but I'm curious to know how each method influences the finished aroma/flavor profile.

Aprendiz said...

Silly question: Is there any minimal change in gravity?

Unknown said...

I've been pondering how to slightly "malt up" a favorite mild recipe. I've tried the usual "add this or that to the mash" and I keep missing the mark (missed pretty badly last time, but luckily I had an imperial stout I wasn't please with and guess what? 50-50 mix of sad stout and meh mild was a hit with the family). The mild really won't handle much in the way heavy-handed dark malts, so perhaps a cold steeped concoction of carafa or medium crystal? Anyway, this was a really fun read. Kick-ass glass, too.

The Mad Fermentationist (Mike) said...

I usually just add the roasted grains for the entirety of the mash. I'd rather adjust the pH with them, than deal with the pH change adding them at recirculation/sparge. If you are getting astringency I'd look at pH and grain choice before I resorted to late additions.

The addition was less than 5% by volume, so even if the gravity was 1.100 that would only add .005. Not all gravity is created equal, the contribution of these roasted grains didn't add any perceived sweetness.

Seems like a fun idea. The crystal won't be especially fermentable without mashing, which may be just what you need! Best of luck!

NJ Beer said...

Do you think this technique could be a viable way to bottle condition older stouts and porters?

As a side note, when you were describing your target flavor profile "hint of dough-in" the first beer that came to mind was Lil' B fresh on tap. It tastes (to me at least) just like cooled wort coming out of the heat exchanger on a brewday. It was really uncanny the first time I tried it; I thought they might have mistakenly kegged it without pitching yeast! Worth a shot if you see it around.

The Mad Fermentationist (Mike) said...

As in that the yeast would ferment the sugars from the roasted grains? Seems too unpredictable to me. I'd assume most of the extract gained from steeped grains in this way would be unfermentable.

It's tricky, I'm not looking for worty-sweetness (which I've gotten in a few beers) I want that fresh grainy flavor/aroma without the sugars.

Jeff said...

Have you thought about fermenting the "blonde" portion of a given porter/stout recipe (base malts, light malts), then mini-mashing all of the dark grains and adding them once the fermentation has calmed down? The reduced fermentation activity might result in less of the aromatics being driven off? Also, mashing the grains rather than steeping would allow you to up the addition without the fear of adding too much unfermentable content.

Unknown said...

You know when you get your score sheets back from a BJCP competition and the judge notes that it needs more malt aroma? I've always wondered how I could improve my malt aromas. You may have hit the nail on the head there. I know this is a way Gordon Strong noted to do dark grains in his beer, but I believe he adds the liquid the boil.

I also cold steeped carafa to do a black wit to not get any roasted character, just to change the color of my wit.

I want to go on your train of thought about making a malt tea. What if you wanted to raise the toasted character of the beer, let's say your porter here. Would a cold steep work with a lighter/toasted malt? Or shall we steep the grains in warm water and hold it at 170 to pasteurize? You have given me a lot of ideas to play with here.

Thank you, I enjoy reading your articles, even though I don't comment.


The Mad Fermentationist (Mike) said...

You'd need to mash the dark malts or cara-malts with a base malt if you wanted conversion, and you'd likely want to boil them rather than just pasteurize to concentrate the gravity at that point. Certainly could be worth an experiment, but it also is starting to sound like adding a second brew day to the batch!

The issue with paler malts is that they need conversion with enzymatic grains to avoid adding starch to the beer. You could do a small mash, quick boil, and then add the fresh wort towards the end of fermentation to allow the yeast to work on the added sugars. You might also look at recipe tweaks that might up the malt character on brew day (swapping American 2-row for something more characterful for example).

CRUSADER1612 said...

Would this type of thing work with adding lighter specialty malts?
e.g I have a Weizenbock, I want to do 1 5 gal batch, but want to do half with rye malt and half with smoked malt.
assess the differences etc. Would this work?

I brew in a Grainfather, and it would be difficult to switch them over accordingly. So a malt infusion, post fermentation, or post boil/pre-fermentation would work well i think.


The Mad Fermentationist (Mike) said...

Lighter malts typically need to be mashed to convert. Really dark grains are converted by the high heat rather than enzymes. You'd likely do better mini-mashing the grains, quickly boiling, chilling, and adding that during the fermentation. Best of luck!

dogum said...

Silly comment... but nice looking glass! Where can I aquire one of those?

Troy_Brews_Beer said...

Thanks for this post. I just tasted an RIS I did and it's lacking some of the darker roast flavors so I'm going to try this method out with roasted barley to try and round it out a bit.

Adrian said...

Awesome! So I brewed a bock, but the color is quite pale and the ABV is a bit lower than what I wanted, I was thinking of doing this but with vodka, have you ever tried this?

The Mad Fermentationist (Mike) said...

Doesn't sound like a great idea to me. I'm not sure what sorts of flavors vodka would pull from the malt. I'd do the malt and alcohol boost separately. There is nothing to say infusing vodka won't work, but I'd lean towards adding more fermentables (malt extract or sugar) to boost the alcohol by fermentation.