Bière de Coupage: Kettle Sours

Since writing the first post in this series, I've been slowly making my way through copies of the correspondence pages from early volumes of Le Petit Journal du Brasseur (provided by Dave Janssen of Hors Catégorie Brewing).  One common question about bière de coupage is whether there might be any shortcuts that would allow a brewer to produce them more quickly or cheaply than by buying or ageing beers for blending.  The answer to questions framed in this way is usually a resounding 'no': if you want anything of the complexity and character of an aged beer, you have to use a well-made beer of that sort. But the authors do often make suggestions about how brewers could accentuate or imitate certain elements of blended beers (e.g. by adding acetic acid), and its in that spirit that I planned the beers for this post.

Most of my attempts at making bière de coupage have involved using aged sour beers, usually drawn from a solera, because I was looking for both tartness and complexity.  But if the only thing you want is to add a bit of tartness to a beer, aged sours are not a necessity: all you need is a beer with a clean and pleasant acidity.  An increasingly popular and reliable way of achieving this is by a process of kettle-souring, i.e. pitching lactic acid producing bacteria into the wort in the kettle, boiling to kill them off once the desired level of acidity has been reached, and then fermenting the beer with a regular strain of saccharomyces.

From my experience, I'd say that beers made in this way tend to be a bit one-dimensional and boring by themselves, and I often find commercial versions to be overly acidic.  But these are all characteristics that make such beers excellent candidates for a certain kind of blending with clean beers: where the acid component can provide a controllable degree of tartness, the clean component can provide the further array of flavours we associate with beer, which are often suppressed (in the case of yeast-derived flavours) or overwhelmed in a straight-forward kettle sour.  This is essentially what Off Color does for their gose Troublesome, and what New Belgium does for their wheat beer Snapshot.

With that in mind, I had the idea of brewing a large batch of kettle sour, and storing it in a keg for regular blending.  My thought was that this would allow me to measure out different volumes of the acid beer as required: a few ounces if I just wanted to a small amount of tartness to a beer, or a gallon or more if I wanted some prominent acidity.

Kettle Sour

Grist: Pilsner (80%), Wheat Malt (20%)

Hops: EKG

Yeast: Safale US-05

O.G.: 1.042

IBUs: 20

ABV: 4.4%

Process

I made a litre starter for the Omega lactobacillus, and let this sit (without agitation) for 24 hours before pitching.  Since each half of the brew-day would be relatively short, I managed to fit them in across consecutive week nights.  On the first day I made the wort, doing a BIAB mash with as much of the total liquor as I could fit in my kettle, then liquoring down after mashout to reach my full boil volume.  At that point I raised the temperature up to just below boiling, then quickly cooled it to around 95°F before pitching the lactobacillus starter.  I wrapped it up in some insulation and a sleeping bag (the same stuff I use if I want to hold my mash-temperature for more than an hour) and left it to sit until the next evening.

The Omega blend performed as advertised, taking the wort down to 3.33 in around 18 hours.  Once I'd confirmed this drop in pH, the rest of the brew-day was quite straightforward: just a normal boil, cooling the wort, and pitching the yeast.  I was a little worried that the low pH would inhibit the US-05, but when I checked the next day there was visible activity after about 14 hours.

Once the beer had fermented out, I transferred it to a five gallon keg, added finings, and put it on my balcony overnight (the 'Chicago winter cold-crash') before transferring to a second keg the next day.  Its been sitting there under pressure ever since: whenever I need some for blending, I just attach the keg to some tubing and measure out the proportion I need.

The beer came out as expected: clean, lemony sourness, without much else going on.  My idea was to use it in varying proportions to add some degree of acidity to different beers, from a tart acidic bite at the end of an otherwise normal beer, to a pronounced but balanced sourness.

Blending

As of writing this post I have used this batch in three different beers, each with varying proportions of acid beer blended in.  For the first I made a dry stout, since I've been brewing them a lot anyway, and I thought it would do well with a small percentage of acid beer.  The second was a wheat saison, to which I was hoping to add a more noticeable acidity.  And third, a wheat beer, which would be the most acidic of the lot.

I came up with some rough percentages before brewing, but also took the time to test them after the beers had fermented out.  One thing I'll say is that this time around it was very clear to me that the perceived acidity increases once a beer is cooled and carbonated.  I tested these blends at rooms temperature, and in every case the final beer ended up a bit more acidic than I'd anticipated.

The proportions for each blend were as follows:

Dry Stout: 5% acid beer.

Wheat Saison: 12% acid beer

Wheat Beer: 33% acid beer.

Dry Stout

A dry stout seemed like an obvious candidate for this kind of blending, and as I mentioned in the first post of this series, there is considerable historical precedent , which is nicely captured in this rather poetic description of "first-class Irish stout" from the 1920s:

There is something at unspeakably seductive and evasive of true description about a first-class Irish stout, It is extraordinarily full and round, mellow and succulent. Yet is it bitter - but that somehow you don't notice. Behind it and enriching the whole lies that soupcon of strange lactic-like sub-acidity. 

The author continues in the same vein, suggesting that its this "strange lactic-like sub-acidity" that is the key to a great stout:

To the mind of the writer it is the will-o'-the-wisp sub-acidity that does the trick in Irish stout. Take it away and you've little left but a black, heavy, dry, but very soft and full mild ale with a lot of hops in it — nothing very characteristic or outstanding. Curious that no one has succeeded in fathoming and grasping that extraordinary suggestion of a rare old vintage wine — something lactic it exposes to us — hidden away in the chocolate-coloured depths. In the export variety you get too much of this sub-acid touch and consequently too little of the limpid polished fullness. But the home consumption product has a veritable perfection of nicety of balance in this respect : it is indeed a wonderful work of the Art of Brewing.

Of course, the beer being described was probably much stronger than the one I brewed, and the acidity likely came from a beer that had been 'vatted', rather than a pasteurized kettle sour.  Still, the basic idea is the same: some small amount of sour beer blended in to add a slight but noticeable acidity to the finish.

Grist: Golden Promise (57.6%), Torrified Wheat (17.4%), US 2 Row (11.5%), Roasted Barley (7.7%), Chocolate Malt (3.8%), Dark Crystal (1.9%)
Hops: EKG
Yeast: Wyeast 1318
O.G.: 1.034
IBUs: 33.2
ABV: 3.1%

Kettle Sour: 3-5%

I'm still working on this recipe, but I felt like the beer came out rather well.  The torrified wheat gives the beer a fuller mouthfeel that belies its very low ABV.  At test-blending the addition of 5% kettle sour seemed to mainly accentuate the bitterness while adding a slightly tart snap at the end of the palate.  However, once the beer was cooled the acidity became more prominent, giving the beer a more noticeable tartness.  I enjoyed it a lot, and the keg didn't last long (why would it, at 3.1% ABV?), but I felt there was room for improvement.  I wanted a little more roastiness and bite, so for the re-brew I increased the O.G. and bitterness, along with the percentage of roast malts, and added a small late addition of Challenger.  I also reduced the kettle sour down to about 3% of the blend.

Tart Saison

For the next beer, I wanted to try making a simple and drinkable saison with a touch of tartness.  To this end, I came up with a recipe for a wheat saison, fermenting it with The Yeast Bay's Saison Blend II and their Lochristi brettanomyces blend.  After primary fermentation was complete I blended the beer with around 12% of the kettle sour (proportions were roughly measured for this one), and allowed it to sit for another month while the brettanomyces and saison yeasts continued to ferment the residual sugars in both components of the blend.  Once it had reached a gravity I was happy with, I packaged it in heavy bottles with priming sugar and allowed it to continue fermenting for another three weeks.

Grist: Pilsner (75.5%), Wheat Malt (18.9%), Torrified Wheat (5.7%)
Hops: Saphir, Bramling Cross, Sterling
Yeast: Yeast Bay Saison Blend II, Lochristi blend
O.G.: 1.038
IBUs: 23.8
ABV: 4.4%

Kettle Sour: ~12%

The final beer is almost exactly what I was hoping for.  The aroma is very fruit-forward, with a mix of citrus from the saison blend and the distinctive aromas of the Lochristi strains.  The beer itself is crisp, tart, and very easy to drink.  Not tremendously complex, but with enough going on to keep you interested.  I think the tartness works particularly well with the more fruity yeast flavours, and I don't know if I'd like this beer as much if I'd used more phenolic yeast strains.  At first I felt the beer was too tart, but as its aged the edges have smoothed out a little and I'm enjoying the slight sharpness.  Still, I'd like to experiment with smaller amounts of acid beer for a more subtle tartness in the finish.

Tart Wheat Beer

For the final beer, I knew I wanted to use a larger proportion of kettle sour, so I decided to try making a wheat beer that I could serve quickly from a keg.  The base was a pretty standard wheat recipe, with lots of European hops rather than citrus and coriander.  I fermented with with Wyeast 1318---an odd choice perhaps, but it was what I had available.  I think in future I'd use a more characterful yeast here.  

I blended the beer in a keg, with two parts wheat beer to one part acid beer, letting it sit for a few weeks at room temperature and then hooking it up to the CO2 in my beer fridge.  I felt that the beer was a bit one-dimensional at blending, so at the least moment I decided to add a small dry-hop of Citra.  This ended up dramatically changing the character of the beer, which I think would have been a bit flat without it.

Grist: Pilsner (51.4%), Torrified Wheat (20.1%), Wheat Malt (14.3%), Munich (8.6%), Flaked Oats (5.7%)
Hops: Saaz Special, First Gold, Styrian Goldings, Citra
Yeast: Wyeast 1318
O.G.: 1.049
IBUs: 21
ABV: 4.8%

Kettle Sour: 33%

The photo on the left was taken quite early on, and the beer cleared up slightly over time, though it always had a bit of haze.  It was fairly tart, but I didn't think the acidity overwhelmed the rest of the beer, which seemed quite well-rounded and moreish.  I think the higher F.G. played a role here. The character from the dry-hop seemed to increase over time, and I wonder whether the acidity played a role in that.  Ultimately, it tasted like a dry-hopped kettle sour, but I found it much more drinkable than the straight-up kettle sours I've tried, which can be hard to stomach after a glass or two.  

I'll be making this recipe again this summer, using Safale T-58 in place of the Wyeast strain, and backing down on the proportion of acid beer to get something closer to a tart wit.  I think these higher proportions would work well in a gose or other adjunct-complimented sour.  Based on my experience with this beer, I think I definitely prefer a blend of clean and acid beer to a straight kettle sour.  If nothing else, it allows for more control over the acidity of the final beer.

My First Kegged Beers

Its taken me a while to get a kegging system, mainly because I don't have the space or the money for the kind of multi-keg setup I'd like.  But after my trip home this summer I decided it was time to look into something basic, if only so that I could brew the kind of fast, low-ABV beers I missed from home without the hassle of bottle-conditioning.  I already had a very small fridge that I'd picked up for cheap from a graduating student---barely enough for one three gallon keg and a five pound CO2 tank, but I had to start somewhere!

I actually bought this fridge over a year ago, and it was only when I noticed the relatively cheap prices for new three gallon kegs at RiteBrew that I finally decided to put it to use.  I bought two kegs, even though I knew I could only fit one in the fridge.  My idea was to prime most beers with sugar, allowing one keg to condition at room temperature while the other served beer from the fridge.

This has worked well so far, and is even easier now that I've built a basic spunding valve to regulate the pressure in the keg.  It also fits with one of my ambitions with these kegs, which is to come as close as I can to something like cask-conditioned beers from back home.  I took my lead here from Terry Foster's advice in his book Pale Ale:

An argument against the use of kegs is that you have to push the beer through the serving line and tap by carbon dioxide pressure.  This might be all right if you are operating at CO2 levels of 2.0 or above, but it is not so good if you want a less gassy beer... There is a very simple way round this that I use.  When I fill the keg, I set the regulator to around  5 pounds per square inch and let the beer equilibrate over a few days.  I draw off a pint or two, set the regulator to 10 pounds per square inch, open the valve, allow the pressure to balance, and then turn off the valve.  The valve is opened only when the flow of beer slows while serving, and it remains open for just a few minutes.  In that way, the pressure in the keg always remains close to 5 pounds per square inch and the beer is perfect, no gassier than real ale served from cask by a beer engine.

So far I've found that I don't need to close the valve: setting the regulator to around 5 lbs per square inch is enough to serve most of the keg, and I can just turn it up for a minute if the flow stops entirely.

The results so far are still a way from cask-conditioned beer, though certainly closer than anything I managed with bottles.  For one thing, the serving temperature is too cold---I've bought the parts to build a temperature-regulator for the fridge, but I need to borrow some tools from a friend to do the wiring, and haven't got round to it yet.  Another problem---obvious in the pictures below---is that all of the beers I've brewed so far have chill-haze, meaning they are not at all bright.  I suspect this is a result of my BIAB process, combined with the shorter conditioning time.

Below are descriptions and photos of the first three beers I served from the keg: all dry and bitter, with a low-ABV.  I expect I'll mostly be brewing beers along these lines, sticking to bottle-conditioning for my saisons and sours, but serving almost everything else I brew (almost all of which is what people call 'session beer') directly from the keg.  In fact, I have a kolsch lagering in the fridge right now while I take a few weeks off booze.

One thing I'm particularly looking forward to is brewing some beers with American hops, something I haven't done for quite a while!  I gave up on making IPAs and pale ales early on, once I realised that it would be impossible to make really excellent versions until I could minimise the amount of oxygen the beer was exposed to.  To solve this, I picked up a cheap second-hand five gallon keg, and my plan is to use this as a primary fermentor for hoppy beers (another use for the spunding valve), transferring them directly to a serving keg (with dry-hops) with CO2.  I found this post from Ales of the Riverwards very helpful here.  But more on that in a month or two.

Bitter

Grist: Golden Promise (97%), Medium Crystal (3%)

Hops: EKG, Styrian Goldings

Yeast: Wyeast 1318

O.G.: 1.044

IBUs: 45

ABV: 4.4%

A standard recipe here, going for a lighter-coloured bitter without too much crystal malt character, nice and dry, with a moreish hop bite at the back end.  Most of the bitters I brew look something like this, though sometimes with slightly more crystal malt, and sometimes with a darker crystal malt.  Besides the bittering charge, this one had an addition of EKG at 20 minutes, and some Styrian Goldings at flameout.  In my experience, Wyeast 1318 tends to mute the hop character a bit, unless your dry-hop, so the end result was a sort soft hoppiness that blended well with the slightly fruity character of the yeast.  Very drinkable: this was my first beer in the keg, and it was a bit of a shock how quickly I finished it!

Dry Stout

Grist: Golden Promise (69%), Flaked Wheat (17.2%), Roasted Barley (6.9%), Chocolate Malt (4.%), Dark Crystal (2.8%)

Hops: Northdown, Challenger

Yeast: Wyeast 1318

O.G.: 1.044

IBUs: 39.5

ABV: 4.2%

What's not to like about dry stouts?  Bitter, roasty, and with a low ABV to boot.  I think I'll be making them a lot more frequently now that I have a keg.  I've been trying to come up with something a bit different from the standard home-brewer Guinness clone: something with a bit more hop character, bearing more than a passing resemblance to De La Senne's Stouterik.  The bitterness was nice in this one, balancing well with the fuller mouthfeel from the wheat, but I would have liked a bit more roast and/or chocolate.  Next time I might try pulverising the roasted barley and adding it post-mash, or perhaps backing down on the roaster barley adding more chocolate malt.  

One of my plans for this year is to try souring a batch of this recipe with the Omega Yeast lactobacillus blend.  My thought is that I could split this into small jugs, and then add it to regular batches to give a little lactic bite, either blending it in the keg and relying on the hops to keep the lactobacillus at bay, or maybe even adding it to the kettle for the last 15 minutes of the boil.  Watch this space.

Pale Bitter

Grist: Golden Promise (92.6%), Torrified Wheat (7.4%)

Hops: EKG

Yeast: Wyeast 1318

O.G.: 1.038

IBUs: 37.6

ABV: 3.7%

Here I was going for a pale beer, along the lines of the historical Boddington's Ordinary Bitter, or its modern counterparts like Marble Manchester Bitter.   Its supposed to be where Wyeast 1318 came from, after all! The original Boddingtons was reputedly intensely bitter, but I've also read that it didn't have much in the way of hop character.  With this in mind I decided to keep all my kettle additions before the final 30 minutes of the boil.  I did add a very light dry-hop to the keg though, giving it a delicate citrus aroma.  

I liked this beer A LOT, but I'm sure I'll tinker with the recipe a bit in future, perhaps trying a blend of different base malts.  To finish, here's a picture that gives a better sense of the colour of this beer (and also shows you where I write these posts!):

Tasting Notes: Belgian Dry Stout

I’m pretty busy with work and school at the moment, so I haven’t had a chance to write some of the posts I had planned for this week.  Hopefully I’ll get a chance to continue the Farmhouse Ales series this weekend with a post on blended beer.  In the meantime, though, I thought I’d post some quick tasting notes on the Belgian Dry Stout I brewed a while back.

A quick preview: the beer is OK---pretty tasty, in fact---but not quite what I was going for.  As I mentioned in the original post, it was inspired by De La Senne’s Stouterik, but as it stands its a very different beer.  For one thing, I’d be surprised if most people would pick up on the fact that this was brewed with a Belgian yeast, unless you told them.  I also think the creaminess from the flaked barley ends up suppressing some of the dark chocolate and roasted notes I wanted: they are there, but very subtle.

I’ll certainly be brewing this one again, but next time I think I’ll replace the barley with malted wheat, and perhaps add a dash of extra dark crystal or even some Special B.  I think such a beer would still fit the “Belgian Dry Stout” description: if anything, these changes bring it closer to something like Beamish rather than Guinness (see Michael Dawson’s `Beamishish’, featured in the most recent episode of Chop and Brew).

Appearance: Looks black in glass, but more like reddish brown when held up to light.  Thin off-white head.  Moderate lacing.

Smell: Bready sweetness and some very light spice (could be from aroma hops or yeast).  Maybe some dark fruit, and very subtle roast notes, becoming more pronounced as it warms up.

Taste: Sweet at first, coating tongue, then more fruity with coffee-like roasted flavours, almost ashy, but very subtle; blending quickly into a nice bitterness in the mid to back palate.  Very slight tartness. 

Mouthfeel: Silky and full, especially for such a low gravity beer.  More than I would like in fact: I think it covers over some of the roast and chocolate notes, and makes the beer seem less dry.  This is one of the reasons I’m going to try wheat in place of flaked barley next time.

Drinkability & Notes: Like I said, a pretty nice beer, but not what I was going for.  I want more of the dark and chocolatey notes, and something drier and less silky.  I’m happy that it doesn’t scream “Belgian yeast!” at you, and I think I can push it further in the direction I wanted with a few modifications.

Brew Day: Belgian Dry Stout

I’ve brewed a few times in the last two weeks, using the pitch of 3522 that figured in this post about top-cropping.  The yeast I cropped there was for an experimental recipe: a belgian dry stout.

This is another beer inspired by Yvan de Baets and Brasserie de la Senne, but this time I decided to brew this recipe even before I tasted the beer that is its inspiration.  I have a slightly strange habit of trawling through brewery websites to read descriptions of beers I’ve never tried.  They often give me ideas for recipes, and it fits with the general idea of trying to make beers that I know I’ll enjoy without deliberately setting out to clone any particular commercial example.  I’d already heard Yvan and Bernard describe the beer in this video from Shelton Brothers, and the description of Stouterik on the brewery’s website was enough to pique my interest further: light, dry, and freshly bitter with complex roasted notes.

I decided to take a typical recipe for a dry Irish stout and ferment it with the Wyeast Ardennes strain.  This has a fairly subdued character if fermented in the 60s, and can add a slight tartness that I thought would complement the style.  The only other change I made was substituting chocolate for some of the roasted barley.  This changed the colour slightly, but I hope it will add to the complexity of the final beer.

One thing that struck me as I formulated the recipe was how similar a basic dry stout is to the saisons de Baets describes in Farmhouse Ales (see quote in this post).  Obviously dry stouts are dry(!), and have relatively low alcohol.  They are heavily bittered with a large dose of low alpha hops, and contain a substantial amount of adjuncts in the form of barley or wheat.

After formulating the recipe, I had to wait a few weeks before brewing, and in that time I had a chance to pick up a few bottles of Stouterik (along with a very different Belgian stout, Drie Fonteinen’s Zwet.be).  The De la Senne beer is lovely: dry and slightly fruity, with a subtle roastiness and firm bitterness, neither of which make it acrid or astringent.  It has some dark fruit notes, which makes me wonder if there isn’t also some crystal in their beer (it may also be their yeast).  Perhaps next time I’ll add 1-2% dark crystal or Special B to bring this out.  The Drie Fonteinen beer was also enjoyable: it had a fairly light, grapey sourness, some chocolate and roast notes, and that slight but distinctive burnt rubber aroma and flavour that this brewery’s beer often seem to have.  As it warmed it began to taste like a slightly sour chocolate, and the grape notes became more like currants or red fruits. Unlike the De la Senne beer, its not something I can imagine drinking regularly, but I’d certainly buy it again.

Anyway, below is the recipe as I brewed it.  This is a work in progress, and I expect to come back to it again based on how this one turns out.  Now that I’ve tasted Stouterik, I don’t think this will be much like it---I don’t think their yeast is the Ardennes strain, for instance, and for some reason I have in mind that their “English aromatic hop particularly appreciated by connoisseurs” is Challenger rather than Fuggles. But I think this recipe will provide a good starting point for further development.  If I decided I want to make it more like the original, I can always culture yeast from a bottle and tweak the recipe.  

Update: Tasting Notes.

Recipe:

   

Estimated O.G.	1.040
Measured O.G.	1.037
Measured F.G.	1.009
ABV.	3.7%
Mash:	150°F
Malt:
69% Maris Otter
20% Flaked Barley
8% Roasted Barley
3% Chocolate
Hops:
Fuggles	60	36.8 IBUs	(45g @4.1%%)
Fuggles	10	1.8 IBUs	(10g @ 4.`%)
Yeast:
Wyeast Belgian Ardennes (3522)