Feb 252012
 
Beer:  100L IPA – split into 4 differently hopped 25l batches.

Brew Date: 19/02/12

Brew Time: 12 till 2am.

Grain Bill – 100L Aim: 5.8%ABV  1.055 @ 70% efficiency

  • 25kg Pale Malt (100%)

Total grain bill: 25kg

We are still experimenting with hops, so we decided to do a basic IPA and then split it down into 4 batches and hop each differently.   This is based upon our tale of 2 IPAs recipe using Maris Otter malt.  However we removed the wheat from the grain bill, as while it gave the IPAs a better head the beers ended up very cloudy.  We also decided to use irish moss to combat this cloudiness, which isn’t something we use very often.  There is no problem taste wise with cloudiness, but it can be off putting to drinkers.

This is the first time we have brewed 100l, so there were bound to be issues.  We used two mash tuns as we didn’t have one big enough for 25kg of grain plus 2 x 25 l of water.  Also the first time we used the new boiler, which we had only just finished putting together 10min before we started using it to start boiling water for sparging.  The new boiler is almost an exact replica of the first one, meaning that we now have 2 x 50l boilers.

Again we had problems with the cold affecting time to hit the hot breaks and prettty much any other temperature that needed to be hit- however half way through brewing we swapped from butane to propane when it started to get really cold (0oC) which meant we had far less problems with the boilers (propane is far less rubbish in the cold than butane).

 

Hops ~60IBU

Hops

Crystal 25L

  • 60min- 19g Pacific Gem (17%AA)
  • 60min- 55g Crystal (6%AA)
  • 10min – 15g Crystal (6%AA)
  • 0min- 30g Crystal (6%AA)
  • Total – 60.61IBU

Sorachi Ace 25L

  • 60min- 40g Sorachi Ace (14.9%AA)
  • 10min – 15g Sorachi Ace (14.9%AA)
  • 0min- 30g Sorachi Ace (14.9%AA)
  • Total – 59.9IBU

Styrian Bobeck 25L

  • 60min- 18g Pacific Gem (17%AA)
  • 60min -50g Styrian Bobeck(6.17%AA)
  • 10min – 15g Styrian Bobeck (6.17%AA)
  • 0min- 30g Styrian Bobeck (6.17%AA)
  • Total – 60.0IBU

Citra 25L

  • 60min -40g Citra (15%AA)
  • 10min – 15g Citra (15%AA)
  • 0min- 30g Citra (15%AA)
  • Total – 60.2IBU

 

Yeast

Safale S-04 (2 x 11.5g)

For this brew we created 2 yeast starters of S-04 at the beginning of the brew, rather than the usual method of just sprinkling a sachet in each fermenter.  We decided to stick with S-04, as it worked really well for the IPAs we made last time, and while we have experimented with Nottingham yeast recently, we didn’t want to change the yeast on top of all the other changes we were making to the IPA recipe. Yeast starter consisted of 1Litre of glucose solution @ 1.050 to make it pretty close to the fermentation gravity, split between 2 sachets to really give them a kick start.

 

 

Mash

Single Infusion, target 65C for 1hr.

mash

Since we were mashing 25kg of grain we had to call into action a second mash tun as the one we use has a max capacity of 20kg grain.  Luckily we know a guy, so borrowed a second mash tun “The Elephant”.  This is going to be the area where we increase capacity next – possibly to a 100L Igloo. Both mash tuns had been inside for previous 24hrs, so didn’t need warming up as much as usual – about 2 Litres of boiling water was used to pre-heat each tun.

Strike Water 50L @ 82C, Grain temp 5.2C

Split grain between 2 mash tuns and doughed in gradually with the magic boat paddle at 2l of water per kg.  So for 25kg of grain we used 50l of water.  Not sure why we used 2l rather than 1.5l per kg of grain this time. (Matt – “think this was just because we had 50L heated up, maybe was just too temping to use the lot, we tend to dough in by eye to a good consistency anyways. We only needed 37.5L”.) Both had to be adjusted with hot / cold water as initial strike temperatures were 60C and 69C respectively which is really pants. Delays due to construction of 2nd boiler and waiting for sparge water to heat during mash, extra mash time doesn’t hurt however.

Doughing In

 

Blue “Elephant” = strike temp 63.0C dropping over 1hr 45min to 61C

Red “Cube” =  strike temp 66.6C dropping over 2hrs to 65C

 

Fly Sparge

2 x 50L @ 71C

Since we used 2 mash tuns we fly sparged 50l water through each one. Both grain beds were maintained above 60oC which is great as this is the temperature that sugars dissolve, however it would have been better if the sparge water was a bit hotter at 75-80oC. First 3l of runnings were recirculated back through each mash tun for clarity.  All runnings were collected in a 120L HDPE barrel and mixed with the mash paddle for consistency so that the OG and the volume could be standardised and split into 4 equal batches.

Collected a total of 114.5L of Wort – measured using a 5L jug to collect from each Mash Tun. This was diluted with a further 4.5L of water to make a total 120L. This allows for 20% boil reduction.

the elephant fly sparging

 

Boil

Carried out 4 x 30L boils, two at a time, each with different hops.  During this process we switched to Propane as our Butane was giving up in the cold weather and the bottle was freezing.

Boil

 

Crystal – just boiling, Irish Moss @ 10min , Final Vol 24.5L, 18% reduction

Sorachi Ace – just boiling, Protafloc @ 10min, Final Vol 26L, 14% reduction

Styrian Bobek – hot break, Irish Moss @ 10min, Final Vol 20L, 33% reduction

Citra – just boiling, Irish Moss @ 10min, 27.5L, 8% reduction

Hops were added as per the recipes at top of page.  We also added a teaspoon of Irish Moss or Protafloc (which was recommended by www.copperkettlehomebrewing.co.uk/)with the 10 min hops. Major reduction in Styrian Bobek is due to an initial hot break which was left to boil for longer whilst waiting for the second boil to catch up before pitching hops. Also had a lot of Hops at 103g but not as much as crystal at 119, other 2 recipes only have total 85g hops. Hops absorb water from the boil.

 

Fermentation

Beers were diluted where necessary to at least 25L and left to cool in the fermenters overnight. Around 9am the following morning we pitched the yeast with the wort ~15C.  We put half of an S-04 starter in each of the 4 fermenters.

Checking OG & Temperature correction

Crystal OG 1.051, Vol 25.5L

Styrian Bobek OG 1.051, Vol 26L

Citra OG 1.054, Vol 27.5L

Sorachi Ace OG 1.054, Vol 26L

4 x 30L Fermenters

All slow at 24 hrs so pitched another 2 sachets of dry S-04 between the 4 fermenters. This lead to good airlock activity at 48hrs and 6 days later the airlocks are still going stir-crazy. All activity finished at 12 days FG____ .

 

Conditioning

A 6% beer should take anything up to a month to condition, the yeast has had an epic time devouring all the sugars so if we keep it alive and give it a little time to reclaim some of the by-products it’s made our beer will taste much better. So we’ll transfer the beer off of the yeast cake into pressurized Corny’s and keep in a nice cool outdoor shed to condition. Normal cellar temperatures would be  ~ 10 – 13oC.

 

Result

Crystal, FG___

James:

Matt:

 

Styrian Bobek, FG___

James:

Matt:

 

Citra, FG___

James:

Matt:

 

Sorachi Ace, FG___

James:

Matt:

 

Conclusion

Good use of capacity, with all vessels being stretched to pretty much full capacity. However inconsistent due to splitting the beer between vessels each time.

 

Improvements
Efficiency 70%, as our malt was fresh we can’t blame that. There are several areas where we can improve efficiency in the future and as James has pointed out it may be worth looking into water chemistry at this scale. We should certainly have achieved 75% comfortably. Likely areas where we lost points in order of severity include:

  • mash strike temperature inconsistency
  • innacurate measurements of liquids in large quantities
  • spillages

 

Strike Temperature

Our mash strike temperature was way out due to a combination of underestimating the cold weather and failing to calculate the strike temp. It could be that whilst we adjusted each mash with boiling or cold water to a favourable temperature,  this may have just saved the top half of the mash tun and the bottom remained at a less desirable temperature, significantly damaging our efficiency. James has pointed out that we should get thermometers mounted in the Boilers – this would make life much easier to track the Strike water / Sparge Water temperatures which may change dramatically during the time taken to dough in or fly-sparge for all we know.

Liquid Measurement

May be worth investing in an accurate 10L bucket to measure our liquids a bit more easily, that 5L jug is awkward when full. Also worth considering using pumps to transfer liquids at this scale as it becomes less manageable by hand. If using pumps James pointed out that we would need to fit sight Gauges to the boilers for measurement purposes. Pumps would not necessarily reduce wort spillages as liquid becomes trapped in the pump and transfer hoses. Also need to install sight glasses and calibrate them for measuring batches. Our Final volumes above are a guestimate at best as Fermenter graduations are useful but renowned for being innacurate.

Consistency

Single larger mash tun would be key to improving consistency. Also the cold is still beating us with a “big stick” so will need to insulate the shed as much as possible and consider adding a bit more insulation to the tuns – especially the lids which possibly lack insulation within them and could be filled with squirty foam.

Currently using one regulator and a T-piece to supply each burner, at 8kw each it may be better to have a gas bottle and reg for each burner.

While not an issue this time as we are only fermenting in 25l batches, it would be good to have a larger FV – a 50 or even 100l one for when we do large brews would be nice.

With these hoppy brews we can start estimating the amount of water that we will loose to the hops, may still be easier to add the water back at the end though to dilute to the full target volume.

Spillages

Shit Happens 🙂

 February 25, 2012  Posted by