Writeup: Dark Grains - Cold Steep vs. Full Mash

drew's picture

Happy Black Friday y'all - how about some advice on making a black colored beer?


You'll often hear advice about mashing your dark grains differently. Instead of incorporating them in when you mash some, like Gordon Strong, recommend adding them during the sparge (aka capping). Others recommend, for the smoothest possible character, adding them as a cold steeped extract. Today's experiment is all about the cold steep

IMPATIENT RESULT: Yes. In the triangle test we put before the audience at the Australian National Homebrewer's Conference, an overwhelming number of tasters could detect the odd beer out. This was single trial with clear cups, but visually when I did it, I couldn't detect a color difference in the environment.


Executive Summary

The idea behind both of these alternative dark malt mash methods is to reduce the amount of acrid astringency found in the final product - does it work? From what you'll see in the next table, it does indeed create a noticeable difference, but the tasters were split on which beer they actually preferred.

And since this is a one brewer operation, we'll cede the floor to our brewer, Helen Hewson, who volunteered to make beers for two travelling knuckleheads in need of a point to make!

The Experiment

As we said before, Helen was asked to brew a Schwarzbier - a beer which thanks to it's lagery supression of esters and phenols should highlight a dectable difference in roast character. (Recipe below). Helen brewed two batches (plus grabbed emergency ingredients) - one with all the grains incorporated into the mash for the full period, the other, she held the roast grains out and cold steeped them to make a "black malt tea" and added that to her beer, speaking of which, let's turn this over to Helen. 

Editorial notes

1) When Helen says "unsteeped", that means the full mash versions - all the grains in the mash tun

2) Helen did an awesome job with this - really funny to see the various stages of panic.

Helen's Brewing Experience

That Time I Brewed a Schwarzbier for Denny and Drew

by Helen Hewson

The Brewer
Helen Hewson works part time at Grain and Grape (the best homebrew store in the known universe), is a beer lover, beer judge, and a lazy homebrewer based in Melbourne Australia. Her brewing equipment consists of a pot and a bag. She refuses to spend any money on upgrading this equipment until she can
afford a Braumeister. She has reconciled herself to brewing with a pot and bag for the foreseeable future.

This is her recollection of that time she brewed a Schwarzbier for Denny and Drew....

The Background
Homebrew legends, podcasters, authors and all round nice guys Denny and Drew of Experimental Brewing are visiting Australia at the end of October 2018 to do presentations and record a podcast at ANHC. ANHC (Australian National Home Brew Conference), is a bi-annual conference that aims to share brewing knowledge and experience, improve the quality of homebrewed beer and raise awareness of homebrewing.

I'm on the organising committee for ANHC. During a committee meeting in mid-August, the following exchange occurred:


    Denny and Drew need someone to brew a couple of Schwarzbiers for the conference. Helen, you brew Schwarzbier. Can you brew the beers?

    Sure. Do you have any details?

Inner voice:
    Crap - I've brewed one Schwarzbier! Last weekend. Yup, first time. Double crap - I've never fermented a lager before. Crap on a cracker, what could go wrong? Wait, how much can go wrong?!!

The Experiment

Brew two identical Schwarzbiers:
    Beer 1: Brew with all grain in the mash (Un-Steeped)
    Beer 2: Steep the dark grains separately for one and add the liquid after the mash (Steeped)

Dark malts gain colour and flavour due to the high kiln temperatures, but lose diastatic power due to that process. Adding them to the mash primarily provides colour and flavour, but can also impart undesirable acrid astringent notes. Cold steeping dark grains extracts the colour and flavour without the undesirable acrid astringent notes which should result in a smoother flavour. The same principle is used for cold steeping coffee.

I've used the steeping method previously for a couple of stouts and a porter with the aim to produce smoother beers. Smoother beers were produced, but my advice to myself for future brews is to increase the quantity of dark grains to gain more intensity of flavour.

The Emails

I need a recipe and some details to proceed. There's an exchange of emails with Denny and Drew, but by the end of August, I still don't have recipe details. These Schwarzbiers will need time to lager, time that they won't have!

11 September 2018
    I email a recipe to Denny and Drew advising that if I don't hear back by the end of the week, this is the recipe I'll be running with. Sometimes you have to prod the bear! [Drew: yes, yes you really do. Sorry, Helen!]

13 September 2018
    The prodding worked. Receive an email from Drew with a recipe for Blackwater V2.

    Blackwater v2 for 20L
            3.5kg (~7.75 lbs) Pilsner
            870g (~2lbs) Munich
            220g (~0.5 lbs) Cara Aroma (or equivalent ~256EBC crystal malt) 330g Carafa Special II (capped or in mash)

        Single infusion mash - 67°C (153°F)
            34g (1.2oz) Hallertau (4.8%AA) 60 minutes 
            14g (0.5 oz) Hallertau (4.8%AA) 20 minutes

        Ferment with a German lager strain.

    I'm working on Saturday, so I'll organise the grain and yeast then.

The Brew Process

16 September 2018

    Commence steeping the grain in 2.5l of cold untreated tap water for use tomorrow, allowing 24 hours of steep time. Resembles ground coffee.

    Commence two starters using a couple of packs of Wyeast 2206 Bavarian Lager and 1 litre of wort for each starter. No fancy equipment for the starters. Shook them very hard at the start, and everytime I thought about it, I'd give them a good swirl.

17 September 2018
    I have to brew outside as I have no covered or sheltered area to brew in. This means I am a fair weather brewer. If it's too wet, too hot, too cold, I'm too lazy or it's too windy there's no brewing.
    Today has dawned fine, but very cold and extremely windy. I have no choice - I have to brew as this is the only day I have available for the next couple of weeks. It's just under 6 weeks until ANHC which will allow only about 2 weeks of lager time.

    My brew days go usually go something like this.....

    BIAB brewing is simple - it's like brewing a pot of tea. Put the required amount of water in the pot, raise the temperature to around 71 degrees (160F), fix the bag to the pot, pour in grain stirring along the way. The temperature will have dropped to around 66-67 degrees (150-152F). Put the lid on, wrap the pot in blankets or insulation, and come back an hour later. Remove the bag and commence boiling and required hop additions. With 10 minutes to go, I'll always add some brewbrite and yeast nutrient. After flameout, I let the wort sit for 5 minutes, whirlpool, put the lid on and leave for about 25 minutes before putting into a cube for fermentation the next day (no-chill method).

    Note, Melbourne has good brewing water and the only treatment I use is a campden tablet to remove chlorine.

    This brew day didn't go quite to plan...... [Drew: Ain't that always the case?]

        Started on the un-steeped beer first. It's about 10 degrees (50F) and blowing a gale. I can't find the campden tablets, so proceed with no water treatment. Mash as normal, and commence boil, but due to the wind, the boil is not constant, and I'm fiddling with the gas burner for the hour. When I put the wort in a cube, I have too much wort left in the pot which indicates my boil-off rate was substantially less than normal. Crap. Why haven't I put marks on the pot? Why don't I have a measure stick? Why this beer?!!

        Start on the steeped beer. It's mid-afternoon, the day hasn't warmed up and it's still very windy. I've found the campden tablets, but don't use one as I want to replicate the un-steeped version as closely as I can. I use less water to mash in to compensate for the extra that will be added from the steeped dark grains. I know the boil-off rate is lower, but don't compensate by using less water or boiling longer. With 10 minutes to go, I add the brewbrite, yeast nutrient and strained steep dark grain liquid.

    Un-steeped OG 1045 Steeped OG 1045

    The low boil off rate has given an OG of 1045 instead of my planned 1048. Boo! At least the OG is consistent for both beers.

        The un-steeped is noticeably darker than the steeped beer
        The un-steeped has a more noticeable roast character.
    (1) Un-steeped, (2) Steeped without the dark grain, (3) Steeped dark grains, (4) Steeped

18 September 2018
    Transported the cubes, fermenters and starters to a friend's house as he has a temperature controlled fridge he's not using at the moment.
    Commence fermenting at 11 degrees (52°F).

29 September 2018

    I'm panicking and I need a contingency. What if this beer doesn't work out? Denny and Drew need beer and I can't just pluck that out of the air. I grab the identical grain and some ale yeast. If the original beers are no good, I'll rebrew them. I can do that and have the beer ready to go two weeks out from ANHC if need be.

02 October 2018

    Un-steeped FG 1014 Steeped FG 1014
        Near identical. The camera can't pick up any difference. 
        Smooth with hints of coffee and chocolate. Un-steeped is slightly more roasty.

    Two weeks in. Gravity not as low as I wanted, but it's tasting good. Hopefully I won't need my contingency! Will commence the diacetyl rest tomorrow.

03 October 2018
    Raise fridge temp to 14 degrees (57°F)

06 October 2018
    Raise fridge temp to 16 degrees (61°F)

09 October 2018
    Un-steeped FG 1014 Steeped FG 1014 Gravity has remained steady.
    ABV 4.07% 
        This is too low for the style. The OG was too low and the FG too high.

        The un-steeped is slightly darker. Maybe different light from previous pic taken 2nd October.

        Despite the low abv, pleased with the outcome. They taste similar, but slightly different. The un-steeped has less nose, but a more roasty flavour. The steeped version has more nose, is slightly smoother, but the flavour is a little less. If nothing goes drastically amiss between now and ANHC, the beer will be ok. No contingency brewing required. Woohoo!!

    Lower the fridge temperature to 3 degrees (37.4°F) for lagering.

21 October 2018
    Time to keg and get carbonating.

26 October 2018
    The two kegs are delivered to ANHC and go to the cool room.

27 October 2018
    It's been a hectic couple of days. I find out that the Schwarzbiers are to be served during the recording of the podcast at lunchtime and that I'm to be interviewed about the beer. Crapity crap crap.

The Podcast Unveiling

The beers are being dispensed and I've forgotten how to brew. Denny and Drew do a couple of interviews, and the beers are delivered to the delegates in the room. Now it's my turn to be interviewed. As I gaze at the audience and see the beer being sampled, I freeze like a kangaroo in the headlights. My inner voice confirms I've forgotten how to brew, the science behind the experiment and basically how to speak. Denny and Drew are gracious professionals and cover up my mumble mouthed responses. [Drew: I like to think we're semi-professionals and Helen still did great]

    Three beers are presented in a triangular testing. In this case, two are the same and one is different. The results are blurry for me (You'll need to listen to the podcast to find out what really happened - I've just made stuff up). A small number couldn't pick up a difference, but most could. Then about two thirds identified which was different. When it was established which was different, it was about 50/50 as to who preferred what. 

    The observation I made when the beer had finished fermenting about the nose and flavour still held true for me - the un-steeped had less nose, but more flavour and the steeped had more nose, but slightly smoother. Some thought the coffee chocolate character was muted in the steeped version. The steeped version had better head retention, although I'm surprised it had any considering how it was served.

    Overall, I was pleased the beer was drinkable and that the experiment led to invigorating discussion, not only about steeped vs. un-steeped, but simple brew techniques and the no-chill method for wort after the whirlpool.

    Thanks Denny and Drew - your presentations were insightful, educational and entertaining, and despite the trepidation, I thoroughly enjoyed being part of Experimental Brewing for a short time. I'll remember with fondness that time I brewed a beer for you guys.

    Keep it Simple!


    I borrowed the Grain and Grape Braumeister for a brew session (Pils) and fell instantly in love (if instantly is a 4 year infatuation before I finally got to caress it's stainless steel dimples). Next blog.... How to Fund a Braumeister on a Six Month Two Minute Noodle Diet.
Cheers and Happy Brewing!

The Tasting

As Helen said, we tasted this beer during the podcast segment you can hear on Episode 79 - Live from Down Under. Samples were served to the audience and we had people blind taste them. For extra fun, Denny and I both knew what the experiment was, but no clue on the pouring setup. Aka we didn't know ahead of time which beer was the odd duck out - e.g. full mash or steeped nor which glass they were in. 

IGOR         Panels Tasters Correct %age p-Value
Helen Hewson 1 57 34 60% 0.000 SIGNIFICANT

So, first question down - yes, our tasters could tell the difference between the beers (for the record, two were the full mashed beer, the odd beer was the steeped grain beer)

When the audience was asked, after the experiment explanation - so the different beer was it steeped or full mash, overwhelmingly (~80%) said steeped and were correct.

When asked which they preferred, the audience overwhelmingly preferred the full mash beer because they liked the most assertive roast note. (For the record, I preferred the steeped version since it felt more like a schwarzbier to me)


Seems like a fairly clear result - when presented with these beers, the tasters could tell a difference between Helen's two beers with the variable of how the dark grains were introduced. Overall impression was a stronger roast character with the full mash and a softer more chocolate like tone to the steeped dark malt version. 

While the audience preferred the full mash version, which do you think you'd prefer?

cold steeping comments

Excelent blog, but I have the following questions / comments: 

  • steeping without the roasted grains produces a different mash pH - should an adjustment have been made?
  • you alluded to increasing the roasted grain amount when steeping, but did not adjust.  I have heard doubling is a good start. 
  • your recipe used Carafa, noted for avoiding tannins / astringency.  Why not use roasted grains?