The aim of the wort production for these spontaneous fermentation trials was to produce a wort akin to that produced at Cantillon. By using a modified turbid mashing schedule, enzyme saccharification is controlled to produce a range of short and long chain sugars/starches to provide plenty of carbohydrates for the captured yeasts and bacteria to consume over the duration of the fermentation.
The specific method of wort production was derived from ‘Wild Brews: Beer Beyond the Influence of Brewer’s Yeast’ (Jeff Sparrow, 2005) whilst the grist and hopping rates were derived from Cantillon’s procedure.
- 5.1 Kg Weyermann Pilsner Malt (65% of grist).
- 2.74 Kg Unmalted Wheat (35% of grist).
- 7.84 Kg Total grist weight.
- 140g aged hops (equates to 350 g/hL – based on Cantillon’s method – 25 Kg of hops/brew with a yield of ~70 hL wort into barrels).
- Total vol. of liquor required for rests = 1.9 L Liquor/450 g grain = 34 L
- Initial dough-in liquor:grist = 0.87
- Expected OG = 1.050. Actual OG = 1.052
- Expected FG = 1.004
- Expeted ABV = 6%
- Pilsner and Wheat were mashed in at 64.5˚C with 6.8L hot liquor to reach a mash temperature of 50˚C. Lid was left off mash tun for the first 5 minutes of a 15 minute rest to allow the temperature drop to 45˚C.
- 6.8L of 100˚C liquor added to mash to raise temperature to 52˚C. Rest for 15 mins.
- 4.5L of wort transferred to the kettle and held at 88˚C. The kettle was already primed with 8L of liquor at 88˚C to cover the kettle elements – 12.5L total kettle volume.
- 10L of 100˚C liquor added to mash to raise temperature to 64.8˚C. Rest for 45 minutes.
- A further 10L of wort transferred to kettle and held at 88˚C – 22.5L total kettle volume
- 10L of 100˚C liquor added to mash to raise to 72˚C. Actual temperature hit 74.2˚C so mash was stirred for just under a minute to allow a drop to 72˚C. Rest 30 mins.
- 13L of wort transferred to kettle before all kettle wort was transferred back to the mash to hit a temperature of 76.8˚C. Rest 20 mins.
- Vorlauf to remove large debris.
- Wort cast to kettle and sparged with 88˚C liquor.
- First runnings after vorlauf were at a 1.042SG
- Mash was slightly oversparged – final runnings were at 1.0025SG
- 140g of aged hops were added to kettle and boiled for 2.5 hours to reach a final gravity of 1.052
- Cast to coolships (20 L/coolship).
- One located in brewery.
- One located in carpark.
- Cool overnight.
- Overnight cooling resulted in a temperature of 18.4˚C for the indoor coolship and 15.1˚C for the outdoor coolship.
- Collect cooled wort in fermenters.
Both inoculations had krausened within two weeks with expected drops in pH and gravity – I will have more information on these early stages once i have received further samples as I would like to provide this information as a collective rather than in dribs and drabs. samples from both inoculations have been suspended and observed under a microscope and it appears than the outside coolship captured more yeast than the brewery coolship, however the brewery coolship appears to have captured more LAB. Again i will give more information on this when I have the complete picture.
Once again, a massive thanks to Will and James for powering through the brewday and Will for the fantastic photographs!