Turbid Mash Spontaneous Ale: Year 3

By: anthony On March 18, 2022

Living in Connecticut has a massive perk - four full seasons. More importantly, three of those seasons run cool. Cool nights allow for me to be able to do a coolship, leaving my kettle out overnight to collect yeast. I have done this in mid-Spring, and now have done one to usher in Fall. The ultimate goal is to get a couple more turbid mash brew days done this season so I can start building up a larger stock of spontaneous ale for the future.

Doing a spontaneous ale requires planning. You can't just wake-up and decide you want to do one on any given day. Careful attention must be paid to the weather - you need clear skies and cold temperatures. The optimal temperature range for a coolship is anything below 44ºF overnight. Anything higher, and you risk nasty bacteria getting into your wort. I got lucky on this brew day, with a daytime temperature of about 55-60ºF, I wasn't brewing in the blistering cold with the extended mash and boil I had to do.

Turbid Mashing may seem intimidating to a first timer, but if you've done a decoction, it's no harder than that. At it's most basic, a turbid mash is a step-mash with two decoction pulls of thick, turbid wort that is kept above 176ºF to halt enzymatic production. I, for ease of brew day and lack of a second burner, throw a second kettle inside the kettle that holds my strike water and treat it as a double boiler. The turbid wort in this kettle tends to float around 195-200ºF.

However simple a turbid mash may seem, the complexity comes in if you don't know your system that well. If this is your first time doing one, I'd recommend keeping a couple gallons of cold water on hand in case you need to cut the temperature of your mash.

The Recipe

The recipe for a spontaneous ale, or lambic, is the simplest part of the entire brew process. Recipes traditionally call for unmalted wheat, but I utilize flaked wheat. It's just a bit easier for me to source than unmalted. Spontaneous Ales are a style of beer that represents a place, so if you're able to source locally malted grain, you should. For this recipe, I used Thrall Family Malt Pilsner, grown and malted here in Connecticut. The Flaked Wheat, however, was not local. Hops used were five-year-old locally grown Cascade.

Bill PercentageFermentable
61%Thrall Family Malt Pilsner
39%Weyermann Flaked Wheat
Whole Leaf Cascade (2015)1201.5oz6

This recipe is scaled for 10 gallons to fermenter. However, due to weather conditions being aridly dry and windy - I ended up with a final output of 7 gallons and a starting gravity of 1.061 instead of 1.051. Please be sure to adjust your water additions if you plan on doing 5 gallons.

One note on this process and coolshipping, plan to brew 2-3 gallons more than you want in fermenter, as an extended boil and overnight cool will evaporate more beer than you expect. I had intended to have 10 gallons into fermenter after the brew day was complete, but I got just enough to fill a 6.5 gallon carboy the following morning.

The Process

As I mentioned earlier, turbid mashing has some complexity, but it's less intimidating than it seems. In fact, if it wasn't such a long process, I would most likely do it for most of my beers.

The first step is a dough-in and acid rest, you're using just enough water to get the grain damp. For this step, I used 6qts of 145ºF water to get the grain to 113ºF. Be wary if you use a stainless mash spoon, as you'll most likely bend the thing. The grain to water ratio is so small that there should be no free liquid, just damp grain. Proceed to get your strike water up to a boil. It'll remain at boil for the remainder of the mash. Rest here for 20 minutes.

The second step, a protein rest, occurs next. I added enough water to raise the temperature of the mash to 136ºF, for me - 8 quarts. Rest here for 5 minutes.

After this rest is the first turbid pull. I removed 2 quarts of liquid and immediately placed the smaller kettle within my hot liquor kettle to get it above 176ºF. I've found, at this step, you can let the turbid wort get to a boil but it requires keeping an additional eye on it, as it can boil over.

From here, I proceeded to add enough water to get to 150ºF. In my instance, it was 10 quarts. Rest here for 30 minutes.

At the end of this rest, I pulled an additional 8qts of turbid wort and added it back to the double boiler.

After pulling the second turbid portion, I added enough boiling water to get to 160ºF. This step was 8qts. Rest here for 20 minutes.

Once the 160ºF rest is complete, I removed the turbid wort from the double boiler and added it all back into the mash, raising the temperature to 167ºF. Rest here for 10 minutes.

After the 167ºF rest is complete, I began a short vorlauf and began collecting my first runnings.

After collecting first runnings, I collected enough sparge water to get me to 13 gallons.

I measured out 1.5oz of aged Cascade hops to use during the entirety of the boil. These hops had been vacuum sealed since 2015. As it's impossible to know their alpha acid percentage, I assumed it was less than half of what it originally was. The hops were added to a muslin bag and the bag was held in the wort using an incredibly high tech piece of equipment - a barbeque skewer.

I brought the water to a boil and proceeded to add the hop bag. Originally, I had intended to do a 3 hour boil, but as I had mentioned, it was an arid and windy day and caused a bit more of a boil off than I had expected. I ended the boil at two hours.

After boiling came the most dangerous step of this process. One that, if you're brewing a larger volume, I'd strongly recommend having a second person. I had to walk the boiling hot kettle 20 feet to where it would cool overnight under my willow tree.

Last time I had attempted to move a boiling kettle I ended up in the hospital with second degree burns all over my ankle and foot. I was definitely apprehensive, but took my time and made it in one piece. It was basically a waddle the entire way there.

I covered the kettle in cheese cloth to prevent any solids from falling into it or unwanted guests getting in to drink it. The wood beams were added to keep the cheese cloth in place.

The following morning, I woke up and began to fill the carboy with the cooled wort. It was bitterly cold out and this took longer than I had hoped. After filling, I moved the carboy to its resting place to allow it to warm up and get comfortable for the next year or so of its life.

The thing about Spontaneous beers is that you never know what you're going to get, or even if it will ferment. I've experienced lag times as long as up to a month. However, this one has begun active fermentation after just 48 hours. A record for my spontaneous beers.

Spontaneous beers are my favorite style of beer to make. The yeast culture from the first one I had ever done has become my house wild ale culture and now lives in a 15 gallon solera. This one was cooled at a different time of year and in a different area of my property, so who knows what this will evolve in to. All I do know is the wait to finally crack the vessel open and try it in six months will be awful. I'm impatient and spontaneous ales have taught a less in patience and allowing a beer to breathe and become a product of time and place.

Once this beer is ready, in a year or two, I'll provide an update on it. But for now, we wait.