Brew # 7 - German Lager

Ingredients

• 2x Morgan's Master Malt Extra Pale Ale malt extract 1.5kg (each)
• 400mL liquid rice malt syrup
• 375g Munich malt
• 35g Tettnanger hops (3.7% AA) (Boil)
• 15g Hersbrucker hops (3.5% AA) (Aroma)
• 5g Irish moss powder
• 3x SafLager W-34/70 dry yeast (11.5g)

Targets

OG: 1.050 - 1.054
FG: 1.014 - 1.018
ABV:  4.2 - 5.25%

Method

Brew day

• Fill basin/bowl with hot tap water and add one tin of the LME to soften (turn occasionally)
• Fill stockpot w/ 12L cold filtered water and start to heat
• Boil 1.5L water in kettle
• Empty one of the Extra Pale Ale LME tins into the pot and rinse tin with boiling water (try to limit the extra water, if possible)
• Stir so LME doesn't stick to bottom of pot
• Tie one end of the grain sock closed, fill with grain, then knot the bag closed, allowing as much room as possible for the grain to move
• Tie the grain sock to the stockpot handle
• Fully immerse the grain bag in the wort to steep
• Continue to raise temp of wort until within the 49-77C range and steep the grains for 30 mins at this temp (hit 49C at 11:38)
• Remove the grain bag, giving it a light squeeze, but do not fully drain the bag (removed at 12:08 - temp 75C - turned the heat down slightly at the end to assure it didn't exceed 77C within the 30 minutes)
• Cover the stockpot and bring to the boil
• After 10mins at boiling temp, add first hops (Tettnanger)
• Boil for 50mins (watch for boil over) - the new stockpot has enough head room to make this unlikely if I leave a 1cm gap in the lid
• I brushed the hop "tide mark" on the sides of the pot back into the wort a couple of times
• Add 1/2 - 1 tsp Irish moss to boil for last 10 mins
• Add second tin of LME to hot water to soften
• Turn off heat (I'm using induction cooktop, so I just 'turn off')
• Add final hops (Hersbrucker)
• Add liquid rice malt extract and second tin of LME, stirring continuously
• Aroma hops, rice extract and LME are allowed to sit for 15 mins to pasteurise, but do not boil
• In the meantime, put ~5-10l of cold water in a sink (sealed with plug) and add two bags of ice
• Whilst the second ME addition is standing, add 10L cold filtered water to sanitised FV (aiming for a total volume of ~22L as some of the wort water would have boiled off)
• Place stockpot in ice bath in sink
• Stir gently, no splashing, ensure no water drips in wort especially water from the ice
• Once wort and FV water temperature equilibrium is ~25C, pour wort into FV using sanitised funnel and filter mesh (I noticed using the funnel and mesh filter gives really good oxygenation - lots of bubbles in the wort)
• I had to add a further 1L of cold filtered water to reach 22L total wort
• OG reading with hydrometer was 1.045 @ 24C (~1.047 with temp adjustment)
• Aerated wort in FV by sloshing around, then place in the fridge

Yeast prep and pitching

• Boil 500mL of water, pour into sanitised container (jar), and cover (Glad Wrap)
• When boiled water temp cools to < 25C, sprinkle dried yeast on top - do not stir - cover
• After 15 mins, gently stir without splashing and place in the warm fridge for min 15mins
• Once wort and yeast temp have equalised (ambient temp), add 500 - 1000mL oxygenated wort to the yeast using the butterfly valve attached to a sanitised spout and length of vinyl tube
• Cover yeast starter and place back in fridge

Fermenting

• Reduce temperature of the fridge with wort and yeast starter to ~12C (0.8C per 90 minutes x 12)
• Oxygenate the wort (slosh around some more)
• Swirl the yeast to suspend the pitch in the liquid, then pour into wort
• Close the fermenter, making sure the dip tube ends up hanging under the float so you can get the beer out
• Leave it alone

Diacetyl rest

• Starting on day 5 (Thurs 13/8), raise the temp by 3C per day (0.5C/4hrs) until it reaches 19C
• Leave (from Sat 15/8) for 4-7 days

Lagering

• Reduce temp by 3-4C per day for ~5 days to a temp of 3C (0.3C/2hrs x 12 x 5 days) - started 6pm, Weds 19th Aug (started a bit early as I need to drink on 30th)
• Note: removed the collection bottle, emptied, and re-fitted (butterfly valve closed) at the same time I started temp reduction
• Took a hydrometer reading - 1.012 @ ~5-8C (1.010 with tenp adjustment)
• ABV = 5%

Coming next...

• After a week at this temp, transfer to keg, carbonate, and drink

Improvements for next time

• Two grain bags will mean the grain can circulate a bit better
• Finer mesh on funnel filter - still lots of solids making it through to the Ferm'us
• ATTACH A PRV!!!
  After a few days, I attached a PRV and didn't think anything was happening until I realised the needle had flipped round the dial. I don't know what the pressure was, but I was releasing with the spunding valve (slowly) for at least 30 seconds, so I reckon it was > 35PSI, which is the max rating for the Ferm'us.
  Next time - attach a PRV at the start if using the pressure kit.