I've always had a luke-warm opinion of gruits (in the general sense gruits are beers that are bittered with herbs other than hops). In particular the bottle of 13th Centurary Grut Bier I tried came off as a muddled mess of spices and herbs. I did enjoy an aged-out bottle of Two Druids Gruit a couple years after Heavyweight Brewing folded; more recently I've had a couple interesting samples from Thornbridge Brewery (Merrie), and Williams Brothers (Grozet) both on cask, but none of those was something I wanted more than a few ounces of.
While I was up in Boston for Night of the Funk in November I sampled a lot of weird/unique/intereting beers, but there were only a handful that I would call inspiring. Cambridge Brewing's 2006 Heather Ale was one of those, it had a nice tartness (from time spent in a Chardonnay barrel with Lactobacillus) and a soft honey/hay aroma from the fresh heather tips (as well as lavender and sweet gale). CBC does a couple of other gruits, but this is the only one I've tried with a sour character.
I have enough long aged sour beers already aging so I wanted to brew something for quicker consumption, to accomplish that I borrowed a few moves from my Berliner Weisse method. I did a quick mash with Marris Otter and wheat malt, followed by brief a 15 minute boil (just enough to ensure the wort was sanitary). I didn't add any herbs to the boil because I'm planning to split the batch, half with lavender and heather, and rest with other flowers (hibiscus, jasmine, and chrysanthemum). I'll make teas with each of the flowers and then dose the beer(s) to taste, allowing me to fine tune the extraction time and flavor contribution for each one (more on that later).
With the "plain" wort cooled I pitched a cup of yeast slurry harvested from the 90 Shilling Stout I brewed two weeks earlier along with some of the multi-strain Lacto culture I keep going. A quarter ounce of boiled/drained oak went into the primary to impart a slightly rustic woodsy character. Hopefully this beer will have lots of subtle complexity, something I can drink an entire bottle of without waiting years for the herbal flavors to mellow.
Experimental Tart Gruit
Batch Size (Gal): 4.75
Total Grain (Lbs): 8.00
Anticipated OG: 1.044
Anticipated SRM: 5.8
Anticipated IBU: 0.0
Brewhouse Efficiency: 70 %
Wort Boil Time: 15 Minutes
75.0% - 6.00 lbs. Maris Otter
25.0% - 2.00 lbs. Wheat Malt
Profile: Washington DC
Sacch I 30 min @ 155
Sacch II 10 min @ 162
Collected 5 gallons of wort
Pitched 1.5 cups of surry from Scottish Stout plus a cup of lacto starter. .25 oz of french oak boiled for 3 minutes, then drained and added as well to primary. Primary ~63 Fambient. Good fermentation after 12 hours.
3/5/11 Blended with teas made from flowers. 2.75 gallons bottled with 2.5 cups of strong heather tea (made with ~2 oz of heather flowers steeped for 6 minutes), a 1 tbls of lavender tea (made with 2 tbls of English lavander). 1 5/8 oz of cane sugar added for carbonation.
2 gallons bottled with 1.5 cups of hibiscus tea and 1.5 cups of jasmine tea, both with about 1 oz of flowers. 1 1/8 oz of cane sugar added for carbonation. FG 1.011
3/30/11 The heather half of the batch turned out well. Nice balance, good heather flavor, not too sweet.
3/31/11 The jasmine-hibiscus half is really quenching, light, and bright. The flavors work well together, should be perfect for summertime.