Keptinis Inspired Brown Ale Recipe - Brain Sparging on Brewing


Sour beer, saisons, farmhouse beer, homebrewing, ramblings

December 16, 2018

Keptinis Inspired Brown Ale Recipe

Some of the most interesting research in beer and brewing right now is coming out of the important work of a handful of people exploring and writing about brewing traditions in northern and eastern Europe and west Asia. There are many pre-industrial brewing traditions in these areas which are largely undocumented outside of their local oral histories. Not only is this research interesting in its own right, but it's extremely important because many of these beers and brewing traditions are dying off. Once people stop brewing these traditional beers they are usually lost to time. At best might be preserved by a mention or two in a beer history or brewing book.

Among these traditional beers and brewing practices are brewing techniques involving baking the mash either to maintain heat or to caramelize the mash to create darker beers. Maybe the most extensive writing on the subject (at least in English) comes from Lars Garshol's excellent blog. He made the point on an episode of the Milk the Funk podcast that historically a large metal kettle for brewing would have been prohibitively expensive for most people so either adding hot stones to a mash vessel or baking the entire mash was a more affordable option. (This is probably true for most of Europe at least at some point in time.) Not wanting to play with red hot stones, I thought playing with baking a mash might be a safer option to take a first hand look at these alternative mash techniques.

Brewing a keptinis inspired beer

This beer will roughly follow the instructions Lars provides for keptinis, a Lithuanian farmhouse beer that is close to a porter or brown ale through baking a mash of light malt. This style of beer is raw ale. It won't be boiled although a hopped sparge addition will add bitterness and protection against infection. Lars takes instruction from an experienced brewer who uses more rustic methods than I do here. The process is simple:
  • Mash in as usual
  • Bake entire mash for extended period of time
  • Boil sparge water with hops
  • Break up baked mash and transfer to mash tun
  • Sparge as usual
  • Collect runnings and pitch yeast
The recipe posted on this page calculates out to a higher ABV beer than I want to make so I've adjusted down from what beersmith calculates as a 9% beer to a 5.7% beer. I won't know how much this brewing process affects mash efficiency. 

Figuring out the mash

One challenge with this process is not knowing how to emulate the oven conditions of the Lithuanian brewhouse. The recipe calls for a starting temperature around 700F which is a little high for my kitchen oven. I'm also not entirely sure how much adding the cooler mash would drop the temperature or how much it would fall over the course of three hours. I would also need to account for the difference in mash size and how that would change the cooling of the oven.

As a compromise I've adopted a modification of my baking procedure for bread. I'll preheat the oven to 500F and then cut it to 450F when I add the mash. I'll drop the temperature periodically if it seems the mash is drying out or turning too dark too quickly. My suspicion is that in the case of the much larger (50kg) mash in the Lithuanian recipe the oven is losing a fair amount of temperature to the initial presence of the mash. The temperature of that mash is probably closer to 450F than its higher starting point. I figure this temperature does a good job baking bread from fairly wet dough and creating a nice caramelized crust so it's at least a good starting point.

Keptinis Inspired Brown Ale Recipe

Batch Size: 3.1 gallons
Est. ABV: 5.7%
Est. IBU: 33.3
Est. OG: 1.061
Est. FG: 1.018
Est. SRM: 4.2
Expected Efficiency: 72%
Grain BillPoundsOuncesSRMPct. Grist
Pils malt702100.00%
Water Profileppm
Bru'n Water Brown Malty
PH: 5.8
Water AdditionsMashSparge
Epsom Salt0.7g0.2g
Canning Salt0.5g0.1g
Baking Soda
Calcium Chloride1.1g0.3g
Pickling Lime
Lactic Acid
Mash ScheduleStep Temp.Step Time
Single infusion mash
Mash volume: 14 qt
Sparge volume: 0.86 gal
Infuse 14qt at 159F14960
Preheat oven to 500F
Once mash temperature stabilizes dropoven to 450F
Bake mash 3 hours at 450F?
Boil 0.45oz Belma with sparge water212F30
Sparge 0.86 gal180F
Boil ScheduleVolumeUnitTimeIBU
Fermentation Schedule# DaysTemp.
Yeast: WY1318
Pitch Slurry from prior batch
Pitch at 64F767
Bottle to 2.2 volumes

Brewing the Beer 

Brewed 11.14.18.

The first thing I can say about this beer is that it is an impressively messy brewing process in a home kitchen. I underestimated the translation of mash tun volume to the pots and pans I could fit in my oven which required me to top up the baking mash after an hour to fit everything due to the water volume. Pulling out baking pans full of boiling mash is not a fun or clean task. Neither was adding more of the mash which splattered all over the inside of the oven. I expected the baked vessels would need a hardcore cleaning but I didn't expect to have to do the same for the oven. I would definitely recommend testing out what you can really get in your oven before committing to the mash.

I ended up using a mixture of pyrex baking dishes, a dutch oven and a small metal bread pan. This presented its own challenge because the different size, surface area and material resulted in the several vessels reaching their final destination at different times. I also think I took the recommendation of adding a lot of water to the mash a little too seriously because even the smallest vessel (the bread pan) needed more than three hours to bake.

One of the finished baked mashes on my dirty stovetop

The entire mash and sparging took seven hours which is about as long as a turbid mash brewday. There's no boil time to add on top (although the wort still needs to chill) but I'd venture a guess I'm going to spend more than ninety minutes cleaning the mess left behind. Had I added less water to the initial mash I think I could have cut a couple of those hours off but it will take some fine tuning to assess how low the water volume can be to avoid too much burning or scorching to the baking mash.

Baked mash mixed together in the mash tun awaiting sparge
Steamy brown first runnings

Despite the mess, the baked mash really works. From 100% pilsner malt I developed a solidly brown wort that tastes a lot like something in the brown ale to porter category. Adding the hop tea cut the sweetness and gave it a slight vegetal taste.

Tasting Notes

Reviewed 12.1.18.

Appearance: Beer pours a rich dark brown with a thick appearance slowly building a tan head. The head first appears thick but deflates back into the beer to remain a thin off-white cover. The beer is quintessentially brown like a dark caramel. The appearance is dense and opaque. Not murky like a questionable hazy IPA but opaque like a brown fog.

Aroma: The aroma is aggressively caramel right up front like hot caramel sauce ready to pour over ice cream. It is sweet and rich with a candy-like quality. Other aromas sit well in the background of toasted bread crust, orange, papaya and cassia. 

Flavor: The flavor is complex with immediate competition of caramel sauce, toasted bread, orange, cassia, walnut, molasses and a surprising woodiness. There is a hint of butteriness and breadiness that follows that this yeast strain can throw. As the beer warms the caramel gives way to more burnt notes that are not acrid but more like the deep caramelization on grilled fruit. With further warmth walnut and molasses take over the flavor. The beer is sweet, although less sweet as it warms, but it is not cloying. This beer tastes like it should be really sweet but somehow it just isn't.

Mouthfeel: The body is full and soft but not heavy like it's appearance or flavor suggests. It reminds me of a beer with a generous amount of oats but it's just pilsner malt. 

Overall: I'm honestly blown away but how good this beer is. The flavor is so deep and complex it's crazy to look at the sack of pilsner malt and think that made this beer without any help from specialty malts. I'm a fan of brown ales but this beer is radically different from any brown ale I've ever tasted. It aligns very well with how Lars describes what he tried from experienced brewers and I'm particularly grateful for his clear explanation of how to brew this beer. 

This is definitely the most unusual process for brewing I've ever attempted and that includes turbid mashing. Baking the mash for this beer is strange and challenging for a regular kitchen but the raw ale aspect is just as unusual. There is no weird fermentation character or sourness to suggest not boiling the wort had any detrimental effect on the quality or cleanliness of the wort. I am absolutely intrigued by both the mash procedure and the raw ale process involved here. I have a lot of beers in the pipeline for now but I definitely need to work in some other raw ales.


  1. Would a brew in a bag be easier? Just place the baked mash back in the bag so you don't have to sparge.

    1. I think you need to sparge to loosen up the mash and extract the sugars, color and flavor out of the grain. When it comes out of the oven the mash is fairly dry and sticky. There is very little liquid left by the time you finish baking the mash.

  2. Instead of 14 qts for 7# of malt, if you used a thicker ratio like 8 or 9 qts for 7# of malt, it would take less space and time but do you think the color and flavor would suffer too much?

    1. Yeah I don't think this is a brewing technique that necessarily benefits from speed. I'm not sure the longer bake is necessary for flavor development but there is also the matter of obtaining complete hydration and conversion in the mash which can be hindered by not starting with enough water.

  3. What is the rationale for the water profile you targeted?

    1. For most beers I use Bru'n Water and target the color and bitter/balanced/malty profiles built into the software because the creator is better at water engineering than I am. I knew this beer would end up malty and brown so that's the profile I selected in the software. I'm not sure if balanced or bitter would have been a better choice but I don't feel bad about the malty selection.