Thursday 11th June 2015 - 200g DME + 2L water + 1.5mL 88% lactic acid (did not measure pH but intention was to lower to about 4.5). CO2 bubbled through to purge oxygen and 5 dl whole pilsner malt added at 45oC as lacto source. Oxygen purged again and added to insulated mash tun with 49oC water.
Friday 12th June - 8am = 37oC. Added fresh boiled water to raise water temp to 45oC. 4pm = 34oC. Added fresh boiled water to raise water temp to 49oC. Noticeable activity from the grain. Rewrapped with cling film to insulate as wont touch again till Sunday.
Sunday 14th June - 6pm = 22oC. Smells of ethyl acetate but didnt get much in the taste. Looks like acetobacter on top of the grain / liquid / air surface. pH = 3.5 but tastes much more intense than the last attempt... More "fruity" acid.
Strike at 75oC. Mash temp 70.6oC. Ooops.
Calcium Sulphate (Gypsum): 2g to strike water
Calcium Chloride 2g added to strike water as 33% solution (not as dihydrate) so scaling / correction factor = 110.98 g/mol (anhydrous) / 147.014 g/mol (dihydrate) * 3 = 2.26. 2g x 2.26 = 4.5 mL.
Lactic Acid (88%): 2.5 mL of 3.5 mL predicted added to strike water
Measured mash pH 5.5 (pH meter reading 0.1 unit high across the calibration range).
After mashing added more lactic acid to reduce the pH to <4.5. Ran out of acid at pH 4.8.
Mash OG = 1.043. Diluted with water to reach 48oC. Crappy thermometer read about 1.5oC lower than the actual temp. Added lacto starter after scooping as much of the surface scum off (strongly smelling ethyl acetate acetobacter scum?). Pitch temp = 46.5oC. Thermostat set to not get that warm this time.
Monday 15th June - 7am = 32oC so raised thermostat but forgot to keep an eye on it. came back and thermometer read 48.5 (so 50oC). Idiot. Turned thermostat back down. time to couple an stc1000 to this thing
Tuesday 16th June - 20L @ 1.045.
Mon 22nd June (Day 6) - 1.020. Brett blend still working very slowly... Fantastic fruit taste but a little light on the acid.
Sunday 28th June (Day 12) - 1.014. Dry hopped with 4 g/L DH.
Sunday 5th July (Day 19) - 1.011. 4.5% ABV. pH = 3.3. Tastes very promising. Clean, tangy dry hopped sour.
Monday 6th July (Day 20) - Added gelatine to the keg (chilled over night in the keezer after purging oxygen) and connected CO2 line at 2 bar.
