Brewing Journey Pt 2

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Experiments

Learning about brewing and how to get it all right


Experiment 1 Malt Milling

Grain milling
Some of what I want to do is to test a few theories and see for myself what works. Not that I do not trust the knowledge of others … just that there is often something that matters t me and not to others.

I have now tested the results from milling a pale malt via my KitchenAid grain mill and comparing it with a three roller grain mill that I borrowed.

Pictures below are of the two results. Which was done in the KitchenAid and which was done in the three roller grain mill? Is this a good grain crush size (the grain mill was adjusted to the recommended setting). Results were slightly different for crystal malt.

Mill A

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Mill B

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Mill A (oval bowl) was the 3 roller mill. Mill B (circular bowl) was the KitchenAid.

There are indeed whole grains in the sample from the 3 roller mill. This is probably because the rollers are a little too far apart in order to operate the mill or because of the wrenching required to move the rollers. There is also more flouriness from the 3 roller mill.

KitchenAid
There is less flouriness overall from the KitchenAid grain mill and it was easy to do the milling. However it only does about 300g at a time. The consistency is very even. Time taken to do 1 kg was around 6 minutes on speed 6. Speed 2-6 seemed to produce the best results. Cleanup and setup was fast and simple. The milling was done on the maximum setting so there is no scope to try and get larger pieces of crushed grain. Crystal malt grains that are smaller crushed well on the second coarsest setting.

3 Roller Mill.
This produced an inconsistent crush at the recommended settings and I closed the gap a little. When I closed the gap more there was more flouriness.Resetting to the recommended gap, some grains got through uncrushed but this could have been because I had to wrench the handle hard to move the rollers and therefore the crushing was probably uneven an perhaps pushed through some grains. The smaller gap was very hard to move – for me, at least. I could do 3-4 kg at a time if I was able to manage to crank the handle for long enough. I understand that there is a motor coming for these mills that will improve ease of use. The roller gaps are infinitely variable so there should be a lot of flexibility fo rdifferent grain types and sizes. Setup is finicky with a strong table and clamps needed to use the mill. Cleaning is not much of an issue. Cost is around $180-220 for the mill according to websites I saw.

Overall, I think the KitchenAid mill is the best. It is of course not as flexible but it is certainly easy. I think the attachment costs about $240 now. I think I paid less than $100 when I bought mine for making bread over 10 years ago.

Experiment 2 – Measuring and managing ferment

After the experiment with grain milling, I have two more interesting ideas to explore. Firstly to try continuous monitoring of SG so that I can pick the time to transfer to a keg or Fermentasaurus for the finishing/secondary/maturing phase. Secondly, I want to try out a clean German ale (Kolsch style) brewed with ESB and Nottingham yeasts. More details in the following, however the main thing to note is that I am doing this with a new process that first ferments with a Grainfather temperature controlled fermenter for as short a time as possible and then transfers under pressure (ideally) to a secondary vessel (Fermentasaurus or perhaps a 19l keg) to further ferment and mature under pressure and with minimal spent yeast.
Experiment #2
This was done using a Tilt monitoring device that sits in the fermenter and comparisons with the previous process of checking 2-3 times a day to see the SG while measuring the temperature of the fermenter sitting under a blanket and warmed with a heat pad. Now that I am using a highly temperature controlled fermenter (heating and cooling) I have the ability to do a lot more manipulation of the ferment process in a less clunky way. The Tilt has built in temperature monitoring as well as the SG, which is the thing I am most interested in.

I will give a more thorough review of the Tilt in another post. For now the important things to note are that it does what it says. It is accurate. It does NOT work well in a double walled stainless steel fermenter but it is usable. It is more suited to plastic containers because it relies on Bluetooth to communicate. It integrates with Brewfather which is where I was able to graph the ferment in the picture below. The ferment was with an extract recipe for a German ale of a Kolsch like style … only the ales made in Cologne and surrounds can be called a Kolsch. Anyway the style is an ale and it is one that is supposed to be clear and free from any off flavours. It is also highly fermentable and … different … the intention is to drink it rather than pour down the sink. I need a new baseline to work with the new setup because nearly everything is different in detail. It is in part a learning exercise and in part an experiment in its own right that will lead on to Experiment #3 which is the really interesting one. One last thing. I used the Lallemand ESB yeast. It is not a Kolsch style yeast at all but this is the experimental part.
Objective
The objective is to use the Tilt and manual testing of the ferment in a Grainfather fermenter to see how long I need to ferment a controlled sample of wort to full attenuation and know when it is “right” to transfer to another vessel to complete secondary ferment and maturing. Along the way, I want to know how well the Tilt works and how best to use the Grainfather fermenter features. For this exercise I am going to only use the heating on the fermenter so the process is closer to the one I already understand.

Method
I made up a wort consisting of two tins of light pilsner malt and 30g hallertau hops. I boiled 10l of water and added the extract to this along with hops for a total boil of 15 minutes … theoretically at least. There was about 25 minutes more of steeping while the temperature reduced to a bit over 85 degrees. I then transferred to the Grainfather, straining the wort to remove hops – the wort was fairly clear and light. I let the wort cool to 70 degrees and added cold water that got the temperature to just over 22 degrees and overall volume to 20l. I rehydrated the yeast at 25 degrees and set the fermenter to 21 degrees for the initial growth stage. I added some Go Ferment to the wort because I forgot to add it to the rehydration jug. I splashed the wort to aerate it a bit more. Pitched the yeast and added the Tilt. I had to be careful to sanitise everything because of the temperatures. I liked the ability to put hot wort into the fermenter. The Grainfather has that over a fermentasaurus. However it is much more of a bulky item and awkward to maneuver. I expect that with cooling pipes and all the rest attached, it will have to stay in place and the wort carried to it. Doing that via a robobrew may not be a lot of fun. Will have to think that part of the process through when doing grain only brewing.

I planned to leave the fermenter at 21 degrees (on the Grainfather display) for 6 hours then reduce to 18 degrees, however it was only 4 hours before the airlock started loudly popping. I turned the temperature down to 18 and was almost kept awake at night by the fermenter – even behind a closed door two rooms away. Monitoring of the Tilt was a bit tricky, requiring a visit to the fermenter to get a reading. That part of the Tilt operation is not as good as I would like. The rest is good for what I want.

The Grainfather fermenter is a pain to use for racking. I ordered a pressure transfer kit but it is not arriving until October. I found that I could only rack the brew to small vessels by sitting th efermenter on a box 50cm high. Getting the ale into a 19l keg or fermentasaurus was impossible because of the difficulty of lifting a heavy weigh to bench height. This is also not feasible with cooling tubing attached. I will have to rig up a pump to do the transfer … of course the fittings for the pump are not in stock either. Bunnings may be my friend or a specialist plumbing supplier. Aqua Safe maybe. That is another story. Malt, hops, water and yeast.

Results
The two pictures below show it all, Really. I was surprised by two things. Firstly how violently the ESB yeast fermenteed. Secondly, the heat generated by the ferment was more than I was expecting. The Grainfather fermenter has an insulated layer inside a stainless jacket. This meant that the fermenter heated up despite an ambient temperature of 14 degrees and then down to 12 after I opened an external window to cool the laundry down! I was finding out what I needed to know.
1. use the cooling – even for ales
2. ESB ferments fast. The ferment was over in 1 and a half days with attenuation from 1.041 to 1.008.

I think the high ferment temperatures mean the ale will be less than clean but it is in small kegs with some dextrose to see if that can clean things up a bit over 2-3 weeks. Otherwise I am happy enough with what I managed to find out. I know what I need to do for subsequent ferments and I know that the process can work well with a few more tweaks. That brings on Experiment #3.

Theory

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A couple of things warrant an explanation. A lovely smooth curve for fermentation against time looks good. However fermentation is a dynamic thing and measurement is a chancy thing as well. A hydrometer is indirectly measuring SG by using buoyancy as the measure wit a scale reading to get the SG, assuming a temperature and then requiring further calculations to get an accurate answer. The Tilt uses bouyancy as well but then calculates SG from its tilt angle and does the adjustment calculations for me. The Tilt device has the advantage of not requiring any draw off of the ale and therefore offers the ability to take frequent measurements without touching anything. It does require my phone to be close to the fermenter to do a test. They recommend that you do not leave a phone nearby permanently because it runs the Tilt batteries flat faster. Besides, I kind of need the phone for other things. The Tilt can be disturbed by bubbles clinging to the side and krausen is that kind of bubble. The early readings were frequent then the next one was overnight. Subsequent readings were late in the day and several times in the evening. I think the Brewfather “smooths the curves” to resemble the theory. The early morning single reading seems to have been a bit low and was probably due to a short sample time as well as some krausen clinging to the device. Later measures taken over longer times showed a lot of variation but then averaged out (the device and app handle this fairly well). A later glitch where there seemed to be no attenuation over 3 hours is due to another short sample period. Lesson – take the samples over 5 minutes or so, not 10 seconds.
Interestingly, the temperature profile tells me a lot about what was happening. A large rise in temperature as the ferment went wild (the airlock was almost hissing) and then falling once the fermentation was nearing completion.

Second part of baselining is to do a proper Kolsch ferment and see how close to the theory I get.

This was done Sunday 12 August. I used pre-prepared 15l Zeirholtz wort with 5l of water added. I will be using this wort as a standard for Experiment #3 to ensure that I have almost identical starting conditions and therefore can make sure that the differences will reflect yeast rather than other factors. The Grainfather fermenter will be used on its own for this baselining. I want to see the effects of using the chiller to keep temperature steady and to then do a rapid cold crash of sorts. The profile will be to start the ferment at 20 degrees and rapidly move to 17 degrees as recommended by Zeirholtz. The yeast was 21 degrees when pitched mid afternoon and the wort 20 degrees. Setting the temperature for fermentation to 17 degrees, it took 14 minutes to reach that. Maybe too fast for propagation to happen. We shall see.
Courtesy of Bunnings, I have fittings to pump from the Grainfather to a keg or Fermentasaurus. That will mean minimal exposure to oxygen and be more convenient. I need more kegs!

Using While Labs Kolsch yeast the ferment looks like the graph below as the temperature is being raised for cleanup and a day prior to 4 degree crashing. The rather ewild swings in temperature are due to the Grainfather fermenter having difficulty handling the thermal effects of the cooler, I think. overall a very sedate ferment compared to the ESB ferment on the same wort.

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Next weekend I will commence Experiment #3.

Experiment 3

Experiment #3 was delayed due to the novel concept of having to do some work … imagine letting that interfere with brewing.

Experiment #3 changed. It changed because I have more things to measure with and new things to try.

Here is what it will be. I want to nail down a process for fermenting that is tied into a rapid brewing method that produces as good a fermentation environment as I can manage while seeing whether fermentation additions, filtering wort and methods of cooling the wort to pitch and ferment a standard yeast. I mentioned previously that I was going to use US05 (first idea) then Nottingham. Now I think London ESB is the yeast of choice for my ultimate goal of making the Amber Porter (my name) which is probably a Strong Ale and could be an Old Ale. It seems to cross that line and also have similarities to a lighter porter too.

So here are the three stages of the experiment and my plan:
Standard Brew Process:
The brew process is to use a recipe of:
5.5 kg Joe White Pale Malt
300g Voyager Voodoo melanoidan malt
200g medium crystal malt
100g Joe White Chocolate malt
London ESB yeast

crush all that in the kitchenaid (takes 15 minutes)
Prepare chemical additions.
Prepare hop additions
Wash and disinfect brew equip

Mash in at 70C then 65 degrees for an hour and back to 74 to mash out for 10 minutes. 17l of water and water adjusted (3g Calcium Chloride, 2g Magnesium Sulphate, 3g Calcium Sulphate). Sparge with 11l of similarly corrected water. Bring to a boil while draining sparge into the wort over about 20 minutes.
Add 50g of EK Goldings for 75 minutes after 5 minutes for the boil to settle down. Recirculate on 1900w (using the insulating jacket) for 75 minutes then add 30g of Fuggles after the power is turned off to cool and the wort is around 90 degrees. Hop additions in small bags. I should have 20l after the longer boil and it should be around 1.065 OG and 70-80 degrees hot. Then the experiment starts …

Stage 1 is to do the standard brew with a defined grain mix and brewing process up to a relatively long Hopstand of 30 minutes. Then try idea #1 of simply transferring into the SS fermenter and cooling within the fermenter. It should work.Set the temperature for initial fermentation to 21 degrees. Add Fermaid 3g. When the temperature is 23 degrees in the wort, hydrate the yeast at 30 degrees and follow the guide to then add wort to bring the temperature from 30 degrees to between 21 and 25 degrees. Pitch at whatever the temperature of the wort is at this time(this is the recommendation). Only stir the yeast in. After 3 hours at 21 degrees, shift to the primary fermentation temperature of 19 degrees.

Stage 2 will vary the fermentation process by filtering the wort aggressively to remove hop and malt particles. Keep the Fermaid

Stage 3 will vary by not filtering and not using Fermaid but aerating the wort.

Stage 4 will try cooling wort directly from the robobrew and transferring to the fermenter at around 23-25 degrees, using the best of the previous processes. I do not expect to see a difference but may taste one.

Stage 5 will take into account what was learned by the previous fourand see if there is an optimum combination or something else to investigate. If nothing else, then I will see the effect of a cold crash after a 5 day ferment without a second vessel ferment.

During fermentation the activity and timing of the ferment will be tracked in detail so that I can see what effect it has. This monitoring will be for the first ferment and the second vessel ferment, see below.

The experiment is to see how techniques in the first ferment and transfer to the fermenter affect fermentation as a whole. I will use a second vessel ferment step in a fermentasaurus to let the yeast clean up. This will be for a week at around 18 degrees but not with high precision as with the first ferment vessel. The purpose of this step is to take the ale off the trub/yeast so as to reduce the impact of that material while it should be able to drop the suspended yeast from suspension over a week. After this it goes into a keg and a few bottles. Taste testing will be the final arbiter.

That is the plan.

A trial using Stage 1 is complete and it came out at at 1.063 OG. Temperature at transfer was just under 70 degrees. It cooled down to 23 degrees in 2 hours and the glycol chiller handled it well. I prepared the yeast a bit early so it sat ready for 20 minutes and it was Nottingham because my London ESB has been delayed. I would have to have redone it later anyway. Simple process and relatively fast with some waiting to do in between short bursts of activity. I will report on the progress over the next week. First measurements show that the ferment started 7-8 hours after pitching. 15 hours after pitching the fermentation was going quickly.

Post

Full run of Experiment #3 Stage 1 underway after an eBay order of ESB yeast. I am proceeding with the planned Stage 1 although I think I know how i want to tweak the process in the end. Yesterday I got a very efficient transfer to the fermenter and ESB yeast going well 6 hours after pitching the yeast. This is Batch #12.

Cooling in the fermenter with glycol works well enough but I think that adopting the Grainfather method of cooling:

  • a counterflow wort cooler sanitised by recirculating wort to the boiling vessel
  • trickling the wort through for 15-20 minutes with quite a bit of cold water
  • wort straight into the fermenter at around 25-28 degrees (estimated
  • then use the glycol chiller to take the wort to 23 degrees and rest there for 3 hours
  • reduce to 19 degrees to ferment 3 days

That is essentially the details for Stage 4 of Experiment #3

I am now thinking I will try a step mash as well with 40 degrees for 20 minutes, 63 for 20 minutes and 69 for 40 minutes – that is for my strong/amber/porterish ale. With luck this will remove a bit of haze. For a Kolsch or IPA I think a mash of 40/20, 60/20, 68/30 will work. Or something like that.

Second vessel transfer by pump and tubing is a right PITA. Pressure transfer is a much better thing by my reckoning. I think I can rig up something on the fermenter by drilling a 1.5 triclover cover and attaching a gas ball lock valve. This will allow me to pressurise to 3-5 PSI and transfer from the valve above the trub/yeast and avoid messing around in a tight space. This method can allow transfer of CO2 to the secondary vessel to minimise oxygen in the vessel.

My method this week was to vent some CO2 in the fermentasaurus and then add 1l of second wort made from 0.5l of water and 200g of dried malt extract, cooled. Add a tea ball of dry hops (10g of Fuggles) on a chain attached to the lid. Seal it up. Pressurise the fermenter to 12 PSI. Pressure release. Repeat. Should be not much O2 left (<2%) in 35l of airspace. This was reduced further as the contents of the first fermenter was pumped in and the headspace volume was about 14l. Another pressurisation and release then attach the spunding valve set to 10 PSI. Any remaining oxygen should be cleaned up by the yeast fermenting the second wort I added.

During transfer by pump, I found that there were bubbles forming in the pump. As I tried to clear on one occasion, the silicone tubing came off and half fermented beer splattered the laundry. At least the floor will be nice and clean by this evening … walls

Update on the German Ale experiment.

This followed the first German ale with Nottingham yeast. The idea was to see if aeration makes much of a difference. If the difference is undetectable then why bother. If noticeable then it is worth doing.

First brew was done with a standard extract recipe and partial mash then hops. Fermented with Kolsch Yeast from White Labs. The variation was to intensely aerate the wort with an aquarium aerator for 15 minutes. Rapidly cooled wort before fermentation. Direct pitched yeast. Fermentation was 18 degrees for 5 days then one at 21 degrees and conditioning for 2 weeks in a keg. Isinglass finings.

Second brew was the same except I only splashed the wort around a bit.

Short story: Experimental brew Kolsch #1 was fairly cloudy and had a yeasty smell to start with and settled down with conditioning. Yeast started to create CO2 after 9 hours at a steady 18 degrees. FG was in about 4 days 12 hours at 1.008. Quite a lot of esters and banana evident. Possibly some higher alcohols too. After conditioning the ale was clearer with some haze.

Experimental brew Kolsch #2 was a little cloudy and detectable yeastiness and clarified very well. Co2 started at around 15 hours and the ferment reached FG in 4 days and 3 hours. FG 1.007. The reading is within the measurement error. Timing was surprising because I would have thought the early start to fermentation would have meant an earlier finish. Final product tested well and was cleaner than the first brew that had a week more conditioning. No noticeable esters or banana.

I would like to do this again to confirm the results because it goes against the advice generally given to aerate. Will do in November or later. BTW, both batches are drinkable and may well improve. I cannot find anything where someone else has experienced what I found in this experiment.

What has anyone else experienced with aeration?

The reply was that oxygen is by far the best way to aerate with significant improvements to quality of the ferment. It is suggested this is due to the yeast being healthier. Yeast manufacturers suggest otherwise, but again opinions differ. This means another Experiment!

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