To save an entire 9 hour brew day, a double batch is required. We have fermentation capacity for 2 x 5 gallon batches with temperature control. Presently we alternate brew days between these in two week intervals, with 2 weeks in primary for each batch.
Water preparation for each batch involves boiling the full batch of water and filtering out the precipitated chalk. As we only have ccapacity to boil 28 litres at a time, it presnently takes two full batches of water to be boiled and cooled for each 5 gallon batch. Each batch boils down to about 23 litres which we then filter and store in a PET carboy. So that has to start a couple of days before brew day. To do this in one step we would need a boiler capable of at least 2 x 28 litres for a 5 gallon batch. If we want to do 10 gallon batches (imperial gallons) we would need double that so we need capacity of at least 4 x 28L. Actually when sizing 10 gallon batches. In fact when I do the sums for a 10 gallon batch the water requires is more like 80 litres. Anyhow by now your probably getting the point that this is a lot of faff and a bigger boiler would take out at least preparing water twice and four times for a 10 gallon batch.
Boiling water for prep is a lot of wasted energy if the pot is allowed to cool on its own or if chilled using a plate chiller, the hot water goes down the drain. Its a good opportunity to grab the retrieved heat and get some stuff washed. And PBW and other percarbonate cleaners like to have hot water if you dont want misty bottles. Washing all fermenters, bottles and kegs in one day saves water and detergent.
Water heated by Gas gives an energy saving compared to electricity. Home supplied natural gas is cheapest but I can't figure out how to get a gas feed in our garage so we are going down the propane bottle route. In the UK, natural gas is a quater of the price of electricity per KWh. However propane bottles are twice as expensive as natural gas, and this still depends on getting a good price for a bottle refill. I have chosen the 13Kg bottles. If you go up to the larger bottles it gets cheaper but 13Kg bottles are intimidating enough to store and move.
Once chilled, water is pumped through an inline carbon filter directly into Burco boiler to prepare strike water. Water has to come down to about 30C for filtration. The Burco boiler brings water back up to 75C before being moved to the mash tun. After draining add another volume of water, stir and leave for 15 mins before draining. Extra step will increase the mash time by about 20 mins.
If the mash tun level is higher than the boiler it wont be necessary for a separate lautering vessel and pump. Wort transferred to the boiler will only need to be raised around 40C as it will be 64-68C for mashing.
If using single infusion lautering, which we are, for a double batch we would need a larger mash tun. But we dont have funds for a new mash tun so we will continue with the 43 litre cooler and batch sparge with multiple steps like most of the homebrew world. I cannot understand why people sparge at all on homebrew size batches.. just add a bit more base malt and save time, hassle, stress. Anyhow maybe next year we will get a stainless steel tun.
Most efficient boiler element seems to be a Paella burner fed with propane gas bottle with low pressure valve. But I can't figure out how to set it up. I have spent a lot of time reading up and no one seems to be able to tell me the maximum weight a Paella burner can take. So i'm going for an 8.7k burner that a home brew supplier where it stand is rated to hold 100 litres.
Had looked at putting together a pot ourselves but eventually settled on an SS Tech 30 Gallon Brew Kettle supplied by the malt miller.
=£310 with delivery
Tried doing a brew on a 2Kw burner.. my advice is never to do that for a 45 litre batch. Ended up using a pump to recirculate wort between the burco boiler and the gas brew pot just to get it to boil. Will need to see how it turns out. Hopefully it will be palatable.
Gas 8.7Kw gas burner for arriving today.
= £44
Already purchased 2 x 13KG Propane tanks
=£23
Total
=£377
