Brew DayThe batch was to be an IPA style beer, bottle finished. The main cooking pot is a 160 L stainless steel insulated vessel that has had the bottom insulation removed and a gas burner attachment added. Also to hand was another large 200 L stainless steel pot and two 100 L stainless steel fermentation vessels.
Here are some of the materials and equipment.
The main pot was filled with water and brought up to temp, around 70-80°C, to this hot water the malt was added and the whole lot cooked for a bit.
While we waited there was time enough for a traditional Bayerisch breakfast of sausages and beer
But then it was back to serious work, time to separate out the liquid and solid fractions. This was achieved by pouring into on of the smaller 100 L fermenter pots with a flat sieve at the bottom, just over the tap. The liquid was drained into a bucket and pumped back into the main pot. Silicon tubing was used that has been boiled prior to use, the tube also has a filter on the intake end.
The solid fraction was then washed through with a fixed volume of hot water 78°C, which was also pumped into main pot adding to the main liquid fraction, which was now about 150 L in total. A separate sample was saved for yeast incubation. Main bulk of the liquid (the wort) was boiled for 90 min, hops were are added at various stages. Some before the 'hot break' (where small flecks of protein were visible in the broth). Once the cooking was complete further hope were added for flavour. A lot of mixing was done when the hops were added.
A small sample of the wort (~5 L) was heated in conical flask to 100°C to sterilise, cooled to 20°C and then had the yeast added. This was incubated at 22°C until the main wort was ready and waiting in the fermentation vessels. The utmost care was taken to keep conditions sterile as much as possible, 70% alcohol spray was used to clean surfaces and anything that could be was boiled before use.
Once the work was cooked for long enough it was transferred into two 100 L fermentation vessels via a muslin filter to remove any particulates and then though a braised plate heat exchanger to bring the temp down from ~95°C to ~22°C. The yeast solution was then added and the mixed with a soup ladle to introduce oxygen to the broth. A polystyrene box was placed over the top to help keep the temperature stable. A 10 L sample of the wort was saved before the yeast was added. This sample is later used a week later on bottling day. Once the yeast have done their thing on the main bulk of wort and turned all the sugars into alcohol the yeast free sample is added back so that the final fermentation takes place in the bottle to provide carbonation.
The sugars content of the wort prior to yeast addition was estimated with a hydrometer, this was later used to calculate how much sugar had been utalised by the yeast to give an estimation on alcohol content. The first measurement OG (original gravity) was about 16.2 [possibly BRIX or °Plato], which the guys were very happy with. The day was rounded off with some more sampling.
The incubator box with the fresh wort samples sitting on top.
Bottling day (Brew Day + 6 days)The main pot was scrubbed out and water was boiled inside for 10 mins to clean, the boiled water was used during the bottle cleaning. The some of the 10 L of wort that was saved from before was added to main pot and the one of the fermented wort was added on top. In this case about 5 L of 'frest' wort was added to appro.x 75 L fermented wort. The fermented wort has a hydometer reading of 3.2, which indicated approx. 7% alcohol!
Bottles up ended in hot water with oxy no rises sanitiser, they were cleaned with tap water on a bottle cleaner, the rim was wiped with 70% alcohol, and then they were filled and capped.
The other half of the wort was to be cold hopped and bottled later.