How we will be producing our Lambic

The more I think about it, the more difficult it is to compose the series of posts around the Lambic Project. For one, I’ve put so much thought and research into it, that it’s hard to talk about one aspect without mentioning all the others. So apologies if some of these posts contain redundant info, I’d rather that than one book-long mega-post.


De-mystifying Lambic

If there is a style of beer that is shrouded in myth and legend to a level of sheer ridiculousness, it’s Lambic. There’s something very Sword in the Stone about it all. Lambic is generally regarded as the most difficult type of beer to brew. If it’s not for the incredibly long wait for maturity, it’s the “turbid” brewing process itself, which can take something like 12-14 hours to complete. While this is certainly the way most Lambic breweries are producing it now, there has been pretty strong evidence that this is not a necessary step in producing a beer true to style. In one of my favorite of his posts; “Brewing Lambic: Mythbusters Style“, Michael Tonsmeire lays out a pretty decent argument:

While a turbid mash does extract starches into the wort, it is no more necessary for brewing a lambic than a decoction is for a Bohemian Pilsner. In Belgium, 30-40% unmalted wheat is part of the legal definition of the lambic/gueuze style, so that is a large part of why there is so little variation. Luckily, there is a beer like Cantillon Iris that proves a 100% malted barley wort can work equally well. While turbid mashes are employed at most of the best lambic wort producers, this may be a result of the fact that brewers who value traditional wort production are also the ones who value adequate aging time, and appreciate classic dry flavors.

This past Saturday I helped brew lambic at Dave and Becky Pyle’s house. If you don’t remember, I attended a blending session they hosted a couple years ago, and their lambic earned them NHC Brewer of the Year honors in 2005. Their wort production method doesn’t deviate far from a standard ale. This batch was half Pilsner malt and half malted wheat, mashed for 75 minutes in the low 150s F. There was no intensive near boiling sparge, and it was followed by a standard 60 minute boil.

The real kicker in this argument, for me, was the mention of Iris, which I had completely forgotten was not actually made with Lambic. The times I’ve had it recently, it came off as Lambic in my mind (you know, despite the generous hopping!). That sensory proof is enough for me honestly.

But what of the koelschip?

De Dolle koelschip, photo: Bernt Rostad

De Dolle koelschip, photo: Bernt Rostad

Lactobacillus, Pediococcus, Brettanomyces

Lactobacillus, Pediococcus, Brettanomyces

This brings us to another problematic aspect of the Lambic lore. The microbes. It’s well known that Lambic brewers allow the wort contact with the air for cooling, using a koelschip, and that some of their microflora are derived from that process. This has lead to a lot of people trying to spontaneously ferment beer in the states, with varying degrees of success. While it is possible to obtain wild yeast from the air in the US and other places however, there is a lot more going on in Lambic. And it’s arguable that the other resident microbes like Lactobacillus and Pediococcus have as much to do with Lambic’s flavor profile as Brett.

Unfortunately this lore of magic yeasts from the air has lead to many people producing “spontaneously fermented” pLambic that really doesn’t have the flavor profile of true Lambic due to the lack of these other characters. I blame this on too much emphasis on one aspect of the tradition, while forgetting one of the most important of the others; barrels positively teeming with all of the necessary microflora to produce Lambic. If you compare the amount in cell count, and types of microflora in the wort in a koelschip, to what is resident in the barrel, the barrel will win every time. Meaning, the barrel with it’s resident flora is more important to the flavor profile of Lambic, than the koelschip.

So then, why so much emphasis on the koelschip? I think it’s because this willful disregard for sanitary measures is so anathema to modern brewing practice. Plus there’s that whole shiny copper pool thing that looks so cool. Either way, for our Lambic we will not be relying solely on spontaneous fermentation, but instead, a mix of cultures. Something that I’d like to dedicate a full post to sometime soon. More on that later.

Tradition, in moderation

While this may seem like we are just breaking all of the Lambic rules, that’s definitely not the point. At the end of the day, we want this beer to taste like Lambic, so to get there, we’ve tried to understand why it tastes the way it does. While some of the practices of traditional Lambic brewing may not be completely necessary for success, we do think there are some notable places where choosing to let tradition dictate is the best course of action.


This one seems obvious, but wood should be involved in any Lambic production. Whether it’s tannins, because the microbes like chomping on it, or for the O2 transfer, wood is too closely tied to Lambic to be left out. In our case we have chosen to work with barrels. While I don’t think it’s 100% necessary, It’s an experience we wanted to have.

Aged hops

While some would swear that these are absolutely necessary, I think I’d agree with Tonsmeire’s article linked above that you could produce convincing Lambic without them. That said, again, I wanted to work with them for this attempt to know what it was like… to have the experience. Also, though because it’s not completely understood if they may impart something in the end. Tonsmeire later writes:

However, the large quantity of aged hops may provide other compounds, glycosides, which can be stripped of their glucose molecule by certain strains of Brett and contribute unique aromatics.

Hops being added to the boil kettle, Photo: Cantillon

Hops being added to the boil kettle, Photo: Cantillon

Aside from the above arguments, aged hops are not that hard to come by these days. Hops Direct has them for a pretty reasonable price.

For what it’s worth, I’m not using aged hops in my starter batches. Instead I’ve been hopping to 10IBU with EKG. I think it should be just fine for starter purposes, but I will be keeping most of the beer to age, so we’ll see how it pans out after a year.

The recipe

Nothing fancy here. We’ll be sticking pretty close to the ratio that Jean Van Roy uses; 65% Pils, 35% wheat. Of course in our case that will be malted wheat instead of unmalted, but that’s as far as we’re going. I’m opting out of the kilned malts some home brewers use to make up for the lack of a long boil. I’d rather not mess with any caramel in my Lambic. Instead, I’ll be looking to wood and fermentation to bring the color into the appropriate range for the style, though I do expect ours to be somewhat lighter in color than some of the traditional examples.

An overnight rest

I don’t have a koelschip, and as I’ve laid out above, I don’t think one is entirely necessary, however there is one aspect of the rest in a koelschip that I think may be useful, and that is simply the overnight rest itself. It’s not that I’m expecting some magic yeast to come take residence in my beer, quite the contrary, I’m looking for stuff no one usually wants; Enterobacter. Jim Liddil breaks it down for us in his essential document here:

It can be argued that without enteric bacterial growth and the subsequent depletion of glucose and production of metabolic byproducts lambic would probably not have the depth of flavor and complexity that it does. Because homebrewers have been “afraid” of enteric bacteria they are missing an integral part of the production process. Studies indicate that the enteric bacteria have a profound effect on the subsequent growth and flavor development in real lambic. In order to achieve the same flavor profile it would seem important to have this initial growth of these bacteria.

For this reason, we will be waiting until the next morning to pitch yeast. Hopefully we will attract some of these bugs to the party.

A long wait

I’m sure it goes without saying but the part of this process I least take for granted is time. We will be waiting a year before we even consider bottling, and I know we may have to wait even longer. I’ve said it before, and I’ll say it agin, I wish I’d started this when the idea first came to me, but hey, better late then never.

An overview of the process

After all of that, the brewing process is going to end up being pretty simple. Instead of the complex turbid or pseudo-turbid mashes we will be doing a couple of infusions over two hours time. First, a one hour rest in the low fifties, as this is generally considered good practice. I doubt however, that our mash tun can hold that temp for the two hours rest, so we would have to use a water addition to raise the temp anyway, I figure we could use this opportunity for a slightly higher temp rest in the mid fifties. At the end of two hours we will vorlauf, run this wort off, and preform a mashout/sparge with water in the 190’s. Due to the long maturation, any tannins extracted will not be an issue, and I want to strip as much fodder for fermentation from the grain bed as I possibly can.

We will start heating the first runnings as soon as we have enough volume to not scorch the wort. Once boil is reached, we will add the hops in large strainer bags. Once the boil is complete, we’ll be struggling to bring the temp down I imagine. We’ll have a fairly large thermal mass, much larger than we usually have as home brewers, and our typical immersion chillers are not going to cut it. I think the best course of action will be to acquire a counterflow chiller, and recirculate the wort until it’s cool enough to put to bed.

Our barrels, soaking, and leaking.

Our barrels, soaking, and leaking.

When ready the wort will be run into a large drum, where it will sit overnight, hopefully collecting some of that enterobacter from our barrel steward’s laundry room. (The barrels will be stored in a walk-in closet adjacent) The following morning we will pitch the yeast into the barrel and rack onto it. The barrel will be fitted with a loose bung while fermentation ramps up, which will be allowed to fall once fermentation is at it’s height, for which time the barrels will remain open. Once primary fermentation is complete, the barrels will be bunged for their long sleep.

While this is an ambitious project by any measure, by far the most difficult aspect of all of this will be the sheer volume of liquid we are working with. We will be attempting to fill three 63 gallon wine barrels in the course of a month. A pretty crazy task. Thankfully we have a 1.5 BBL system at our disposal to help with it, but still, working with such volumes will surely present complexities thus far unknown. All I can try to do is think through every aspect as thoroughly as possible, either way I’m sure we are in for a learning experience.



  1. Ryan Williams · · Reply

    Agreed…don’t need a cool ship. It’s a shame publications and fanboys with little brewing experience are pushing this hard because it’s seems like a huge investment and might discourage brewers from getting in this game. Just brew a good lambic, age it, establish a good culture and perpetuate it in preceding batches of lambic. Coolshiping is also extra handling and could be inefficient time wise. To each their own though. I’ve Been a cellarman at place that has gotten some good results without coolshipping. Just barrel care, good brewing.”””blending If you brew a good lambic and are careful with your barrels you can’t fail. Used barrels might get you a good result off the start but you may get some bad ones and have to establish a way to test and weed those out.

    1. Yeah, agreed. It’s much more technique than magic.

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