Zuur Tafelbier - Hybrid turbid mash & souring with acidulated malt

Tafelbier or Table Beer is the term used for Belgian and Dutch beers that have an ABV between 1-4%. As the name implies, these are traditionally consumed at mealtime by the whole family. Yes, even the kiddies get to drink it.

One of the main features of these table beers is that the mouth feel is higher than one might anticipate, usually because of unfermented sugars/malt sugars. Traditional versions do not use artificial sweeteners nor are they excessively sweet. More modern versions of this beer incorporate sweeteners such as sugar and saccharine added post fermentation to sweeten the palate and add to a perception of smoothness. A mild malt character can be evident. Aroma/flavor hops are most commonly used to employ a flavor balance that is only low in bitterness. 

One of the methods used traditionally to make Tafelbier is whats called a turbid mash. It is also common for Lambics. This is a fairly complicated process. If you want details on the the full mash schedule check out this page: http://bergsman.org/jeremy/lambic/making.html

Not only was I interested in making a Tafelbier, but I wanted to incorporate some sourness into it. Essentially a petite sour beer. One great thing about a Tafelbier is the quick turnaround. Souring with Lactobacillus would have really slowed the turn around down. So I decided to try to use Acidulated malt to get a nice tartness.  In an effort not to impact the mash PH too greatly I held out the acid malt until late in the mash. The acid malt made up around 25% of the malt bill. This malt was added to the mash 30 minutes into the saccharification rest. I continued the sacch rest for another 25 minutes after the acid malt was added.

Back to the turbid mash. This is normally done using infusions to raise the temp. It begins with a very thick mash. It is similar in a way to a decoction. The difference with decoction is your mainly pulling your grist out of the mash and boiling it. With a turbid mash you are looking to pull liquid only.

The idea behind using the technique today is that you pull a % of wort before the enzymes have been activated. Then quickly heat this portion to around 180 degrees to denature it, or destroy the enzymes. Then at some later point in the process this denatured wort is added back into the mash. For lambics and other wild ales this provides long term food for the brett and other bacteria since saach yeast cannot consume these large complex sugars. In the production of table beers, this process can help too add to sweetness, mouthfeel, and body.

For this beer I was interested in doing a turbid mash. However I did not want to follow the Cantillion process step by step. This is an experimental beer and I was trying to just come up with a hybrid method to hit the main point of the turbid mash which is to keep additional unfermentables in the wort.

Once I finished the boil and chilled the wort I separated it into two fermenters. In one I pitched GigaYeast GY048 - Golden Pear Belgian. In the other I pitched White Labs WLP670 - American Farmhouse blend. The blend also contains some brett. I plan on bottling some of this one for a longer term aging to see if I can get some additional funkiness from the brett and the turbid mash.

The Hybrid Turbid Mash

The 3 quarts I removed from the mash and added  to the kettle 

To start I mashed in 11 pounds of grain with 7 gallons of water. I recirculated for around 5 minutes and pulled off 3 quarts of wort. At this point the mash was thick. I moved the 3 qrts into my boil kettle where I quickly raised the temps to over 180 degrees. I kept this mash liquid in my kettle until I was ready to mash out. I just kept an eye on this and never let it boil.

At the same time I was heating the pulled wort I continued with my main mash. Here are the steps to with the main mash:

1) 20 mins @ 122
2) Raised to 157 over about 15 minutes
3) 30 Mins @ 157
4) Slowly added 4# acid malt over 10 mins
5) 20 Mins @ 157
6) Added the 3 quarts back into main wort for mash out
7)  Raised temp to 168 for 10 mins (mash out)
8) Drained to kettle
9)  Added 11.5 gallons of sparge water.  Recirculated for 15 mins
10) Drained to kettle
11) Collected 15.25 gallons of wort

Zuur Tafelbier

Belgian Table beer

Type: All Grain	Date: 02/02/2014
Batch Size (fermenter): 11.00 gal	Brewer: Michael
Boil Size: 15.48 gal
Boil Time: 90 min	Equipment: 26 gallon- All Grain
End of Boil Volume 12.48 gal	Brewhouse Efficiency: 80.00 %
Final Bottling Volume: 10.25 gal
Fermentation: Ale, Two Stage
Ingredients
Ingredients Amt Name Type # %/IBU 7 lbs Pilsner (2 Row) Bel (2.0 SRM) Grain 1 46.7 % 4 lbs Acidulated malt (Add late in mash) (1.8 SRM) Grain 2 26.7 % 2 lbs 8.0 oz Caravienne Malt (22.0 SRM) Grain 3 16.7 % 1 lbs Oats, Rolled (1.0 SRM) Grain 4 6.7 % 8.0 oz Aromatic Malt (26.0 SRM) Grain 5 3.3 % 2.00 oz Saaz [3.75 %] - Boil 60.0 min Hop 6 14.3 IBUs 1.0 pkg American Farmhouse Blend (White Labs #WLP670) [50.28 ml] Yeast 7 -
Beer Profile
Est Original Gravity: 1.037 SG	Measured Original Gravity: 1.036 SG
Est Final Gravity: 1.009 SG	Measured Final Gravity: ? SG
Estimated Alcohol by Vol: 3.7 %	Actual Alcohol by Vol: ? %
Bitterness: 14.3 IBUs	Calories: 0.0 kcal/12oz
Est Color: 6.0 SRM
Mash Profile
Mash Name: Temperature Mash, 2 Step, Full Body	Total Grain Weight: 15 lbs
Sparge Water: 11.5 gal
Mash Steps Name Description Step Temperature Step Time Protein Rest Add 7.00 gal of water at 130 F 122.0 F 20 min Saccharification Heat to 157.0 F over 15 min 157.0 F 60 min Mash Out Heat to 168.0 F over 10 min 168.0 F 10 min
Sparge Step: Batch sparge with 1 steps (11.5 gal) of 168.0 F water Brew day Notes: Mashed in at 131 w/ 7gallons Dropped to 122 Recirculated 5-6 mins, drained 3 Qts of wort and added it to kettle (raised temp to 180) Recirced for 20 mins @ 122 Raised temp to 157 over 15 minutes Held temp at 157 for 30 mins Added 2# acid malt recirc 5 mins Added 2# acid malt recirc 20 mins Added 3 qrts of wort back to main mash Mash out @ 168 10 mins Drained Tun, added 11.5 gallons from HLT Recirc 15 mins at 168, drained Collected 15.25 gallons of wort in Kettle. Boiled for 90 mins Added 2 oz Saaz hops @ 60 minutes Chilled, filled two 5 gallon carboys. Pitched American Farmhouse in one Pitched Gigayeast Golden Pear in other

Early in protein rest

Rev Brew lab Brewery

Update 4/18 - Let's chalk this brew up as a good starting point, but needing some sweeping changes. The good: What an amazing full mouthfeel for such a small beer. The tartness was also pretty spot on for what I was hoping for. The Bad: I knew this would forever be cloudy, but it took quite awhile to not look like milk (ewww). The smell was so strong of yeast it was hard to handle.

The version with the gigyeast strain did not stick around long. After several weeks in the keg I tossed it out.

The farmhouse blend was much more promising. I so wanted to like it. It really was just the nose that was such a turn-off. I ended up dry hopping it with 2 oz of citra in the keg to try and mask it as much as possible. That helped a little, but I also just recently gave up on that version as well and dumped it. I was a little sad about it, especial after I dumped it and noticed that only about 10-15% of the hops I put into the keg made contact with the beer. Oops, I guess I need to get some marbles of something to weigh those down in the future.

I will try something like this again, but I will most likely cut back on the 'turbid' amount I remove from the protein rest.