Sunday, 5 June 2016

Bière de Coupage: Boxed Lambic

In the previous two posts in this series I described my experiences making bières de coupage with both kettle-soured and mixed fermentation home-brew.  The inspiration behind all of this was the ongoing tradition of using aged beer from lambic breweries for blending, and when I conceived of this series of posts I knew that I wanted to look into making such a blend myself.

First, I needed to get my hands on some lambic.  As these advertisements from old volumes of Le Petit Journal du Brasseur show, lambic brewers have a history of selling aged lambic for blending, which continues in the present day sale of `bag-in-a-box' lambic from certain breweries.  These boxes are occasionally available from Belgian webshops that ship to the US, but the price of shipping makes them prohibitively expensive, to the point where for a while I felt that I couldn't justify the cost (they would be much more affordable if I still lived in England!).  I had all but given up on the idea, when a fellow brewer from my homebrew club offered to split the shipping on an order with me: it only saved a little bit of money, but combine that with an upcoming birthday and I had all the excuse I needed to ask for a box of lambic, along with a few examples of bière de coupage not available in the U.S.

My original plan was to purchase a single box of Oud Beersel lambic, which I would then split between two 11.4 litre (3 gallon) batches of beer.  Each box contains five litres of lambic, so subtracting about ~400ml for tasting and other analytics, that would leave 4.6 litres to divide between the two batches, or 2.3 litres each.   Although I was tempted by the idea of just adding the lambic to each batch at bottling, and relying on the fermentation of residual sugars for carbonation, this felt like too much of a risk for such an expensive batch of beer, so I instead decided that I would simply remove 2.3 litres of beer from each carboy, and replace it with lambic, giving me a blend of approximately 20% lambic to 80% home-brew.  I could then leave the beers to undergo a secondary fermentation for a few months before packaging.

The Home-Brew

The first thing to do was to make the home-brewed beers.  I settled on two recipes, one for a 'basic' saison made with 100% pilsner malt, and the other a variation on a spelt saison that I've been making a lot recently.

Spelt Saison

Grist: Pilsner (60.6%%), Unmalted Spelt (24.2%), Vienna (15.2%)
Hops: EKG
Yeast: Saison Blend (Yeast Bay Saison Blend II, Wyeast 3726)
O.G.: 1.044
IBUs: 28.3

I have a separate post scheduled about the spelt saison recipe, so I won't write much about it here.  It typically includes between 20-25% spelt, often with something like Vienna or Munich malt to give it some additional character.  In this case I went with Vienna, and backed down slightly on the IBUs.  It was fermented with a blend of The Yeast Bay's Saison Blend II, and Wyeast 3726.

Basic Saison

Grist: Pilsner (100%)
Hops: EKG
Yeast: Saison Blend (Wyeast 3724, 3726)
O.G.: 1.060 (Predicted: 1.055)
IBUs: 36.6

I've been mostly using cheap North American pilsner recently, but I decided to splash out on some Weyerman Bohemian pilsner for the basic saison.  This is supposed to be slightly under-modified compared to many other modern pilsners, and I've enjoyed its more pronounced flavour when I've used it in the past.  I put the grist through the mash-steps I use for adjunct-rich beers, with rests at 131F, 145F, and 154F.

Since I knew the beer was going to be blended with lambic, I also decided to do a longer boil, hoping to match the richer colour and perhaps some of flavours of the lambic.  In the end I settled on a three hour boil, which was shorter than the one I used for this bière de garde, but still long enough for a noticeably darker colour (relative to both the start of the boil, as shown in the picture below, but also to the same volume of wort of comparable strength made with a shorter boil).

The rest was all quite straight-forward: EKG early and mid-boil to around 36 IBUs, and a blend of Wyeast 3724 and 3726 for primary fermentation.  The original proportions were approximately 70% 3724 to 30% 3726, but this was the second or third generation, so I have no idea how that balance had changed.  I was aiming for a O.G. of around 1.055, but between the longer boil and the step-mash with an unfamiliar malt I ended up overshooting by 5 points.

The Lambic

While I was doing all of this, my friend placed his order at Belgium in a Box, and it arrived about a month after I brewed these beers.  As I said above, I only ordered a single box of Oud Beersel lambic, and had planned to split it between the two beers.  However, when my friend dropped off my order, he had added an extra box of Timmermans from his own stash!  Incredibly generous, and very exciting for me.  (Thanks Tarsicio!)  That made me re-think my plans slightly.  I knew I wouldn't have time to brew many more beers before leaving for the summer, so I decided to make an additional blend with beers I had in my brew-closet.  But first, the lambic...

I've copied out my tasting notes for each box below.


Gravity: 1.009
Tasting Notes: Nutty aroma, almost like marzipan.  Assertive, lemony sourness.  Nice but one-dimensional.  Will add a pleasant acidity.

Oud Beersel

Gravity: 1.006
Tasting Notes: More complex than the Timmermans, with a mix of bright fruitiness and light funk.  Sulphurous note that is a bit overwhelming at first.  Bit of plastic with the fruitiness.  Only lightly tart, compared to the pronounced lemony acidity of the Timmermans.  Preferred blending component.

The Blends

Since I had more lambic than I had anticipated, I let myself take larger samples from each box for tasting, gravity readings, and blending experiments.  Luckily I had just made some pulls from two of my soleras (ECY20, Roeselare), so I had some aged pale sour on hand in carboys and jugs.  The ECY20 pull has a pronounced lemony sourness, along with a bit of hay and light funk.  I decided to keep this for blending with other home-brew, as I like the acidity it adds, but that wasn't needed here.  The Roeselare pull (which has had a lot of dregs added over the year) was more funky, with a softer acidity.  I felt like this worked better with the boxed lambics. I also had five gallons of an adjunct sour that I made a few years ago.  For a long time this suffered from a strange minty/herbal taste that I attribute to 'aged' hops that added more bitterness than I expected, but that flavour was finally beginning to fade, and I found that the beer added a nice complexity in blends.  So that gave me the following components to play with:

  1. Basic Saison
  2. Spelt Saison
  3. Roeselare Solera
  4. Adjunct Sour
  5. Oud Beersel Lambic
  6. Timmermans Lambic
Blending these together was fun, but only moderately informative.  As with my previous blending session, I found that I got palate-fatigue pretty quickly, and that it was hard to make well-founded decisions between different possible blends, beyond ruling out the ones that I felt had obvious flaws.  In the end things went the same way as last time: I was testing out pre-conceived blends to see if they would work, rather than coming up with a blend on the spot.

I decided to stick with a variation of my original plans for the saisons.  Instead of splitting the Oud Beersel between both batches, I used it in the basic saison, and used the Timmermans for the spelt saison.  I racked out approximately 2 litres from each saison, and replaced it with an equivalent amount of lambic, for a blend of ~18% lambic to ~82% saison.

This left me with approximately 2.5 litres of each lambic (subtracting the 0.5 litres I took for sampling and testing blends).  I combined this in a five gallon carboy with 11.4 litres of pale sour racked from my Roeselare solera, along with the 2 litres of basic saison described above and approximately 2.5 litres of two year old adjunct sour that went unused in my Autumn blending.

All three blends have been sitting in carboys since blending, and each has shown some signs of fermentation. The Oud Beersel box was clearly alive and fermenting on arrival, as the bag was swollen to the point where I was worried it might burst, and continued to swell after I had let out some of the gas.   I didn't see any comparable activity from the Timmermans, but a pellicle has formed on the blend, so I think it also contained active yeast and LAB.  I haven't taken new gravity readings, but I know that I won't be able to package these beers for a while because I'm running low on heavy bottles.  I'm hoping I can bottle them before I leave for England in July, but it may have to wait until the end of the summer. 


  1. Really interesting idea - how did you go about transferring from the box? Straight from the spout or with a piece of tubing?

    1. Good question. I opened up the top of the boxes and cut a corner off from the top of the bag, then racked the beer out using an auto-siphon.

  2. I know this was an awesome blending day! So awesome to use commercial Lambic in the blend. I love these posts btw. Great writing and great information.