RAPT Temperature Controller - Temperature Calibration

After a few uses of our RAPT Temperature Controller, as a matter of interest we decided to check it's accuracy to ensure we were actually fermenting at the temperature we had set on the controller.

Much to our surprise we discovered that the RAPT Temperature Controller was a whole 3°C off when compared to both our Inkbird Temperature Controller, and a stand alone Weber branded meat thermometer.

After inserting the probe for the Inkbird into the same location directly next to the probe for the RAPT Temperature Controller on our fermenter, we had a reading of 23°C on the Inkbird and 19.9°C on the RAPT. Our Weber probe thermometer had the same reading as well at 23°C.

Since both the Inkbird and Weber thermometers reading the same temperature, the RAPT Temperature Controller was the outlier and therefore presumed to be inaccurate. 

To be clear, we never bothered to run a calibration on the RAPT Temperature Controller - but then again we never calibrated our Inkbird controller either and it seems to be very accurate.

Looking at the instructions for the RAPT Temperature Controller - it has details on how to perform a calibration but suggests you use ice water in one glass, and "hot" water in another.

We initially attempted running the calibration against ice water, and near boiling water which improved the accuracy but it was still around 1.5°C out at the temperature range we really need to measure (around 18°C - 20°C).

We got better results by calibrating against ice water, and another "warm" water solution at around 30°C which got us to within 0.4°C which for us is close enough.

Here's the process for calibration;

Setup two glasses of water - put some ice in one (to make it as close to 0°C as possible) and another with warm tap water - around 30°C.

You will need another (accurate, previously calibrated) device to measure the temperature of the water to calibrate the RAPT Temperature Controller against - for us we will be using our Weber meat thermometer.

Put the second thermometer and sensor probe for the RAPT Temp Controller into the ice water solution first.

You can see when we did this our RAPT Temperature Controller is reading -1.9°C compared to 0.2°C from our meat thermometer.

Press the Enter button on the RAPT Temperature Controller to open the menu, then press the Down arrow to highlight Settings, then press the Enter button again to open the Settings menu.

Use the Down arrow to scroll through the options and locate the option for 2 point calibration. Press Enter to select the 2 point calibration option.

The calibration screen will now be displayed for calibration point 1. Make sure the probe is fully submersed in the ice water and wait for the number next to ADC Reading to stabilise. 

Once the ADC Reading number has stabilised, use the Up and Down arrows on the RAPT Temperature Controller to adjust the Temperature value so it matches the value on your other thermometer. In our example below, we set the RAPT Temperature Controller to a temperature of 0.2°C to match the temperature reading on our meat thermometer.

Press Enter to complete the calibration for calibration point 1.

You will now be prompted to repeat this step for a second, warmer solution for Calibration Point 2. Repeat this process in your other water solution after moving the temperature probe and your second thermometer and press Enter to finalise the calibration once you've adjusted the temperature to match.

Once completed you are returned to the menu screen - there's no other confirmation messages or anything to say the calibration has been completed.

As previously stated, we got more accurate results by calibrating against a second solution at around 30°C. We were still almost 0.5°C out though, so for the best accuracy we'd recommend calibrating against ice water and a warm solution at around 20-25°C.

So if you have a RAPT Temperature Controller and haven't calibrated it yet, it's well worth investing the time to do so. Temperature control is known to be such a crucial part of fermentation and ensuring the best possible product being produced by your yeast.

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West Coast IPA - BrewZilla Brew Day

Our latest brew day features our attempt at a West Coast IPA. You can view our full recipe here, as well as our recently published West Coast IPA Recipe Creation Guide for some ideas and guidelines on how to build your own West Coast IPA recipe.

Here's our sack of grain - at just under 7kg in total there was plenty to be added - we sourced all the ingredients from our friends at 41 Pints of Beer.

Our first step on brew days is to get our BrewZilla and Digiboil setup with their respective amounts of water, and water adjustments made as per the calculations from our recipe in Brewfather, as well as a half camden tablet in each to remove any chlorine from the water.

We adjust our water with calcium sulphate, magnesium sulphate and calcium chloride.

In our last brew we adjusted the pH of our mash for the first time using phosphoric acid - and in this brew we're also going to attempt to adjust the pH of our sparge water as well. Our research suggests that a pH lower than 6 is ideal for sparging, and any higher can lead to more tannins being extracted which can cause some astringency in the final beer. The tap water we use for brewing is more alkaline with a pH of over 7, so we’re thinking adjusting it is probably a worthwhile thing to do.

Part way through our mash in and you can see we've got a really thick mash - we reduced the amount of water in the mash to around 23.5L - the BrewZilla profile in Brewfather would have had us using more water than this and it would have been full to the brim which can be difficult to manage. The reduced water volume of 23.5L worked pretty well and seemed about right for a grain bill this size.

After letting the grain bed settle for 10 minutes after doughing in, we took a pH reading and we were bang on exactly what our recipe predicted at 5.34 - perfect!

What wasn't so perfect was when we checked the pH of our sparge water to find that the water had somehow reached a pH acidity level of under 4 - ie. super acidic which was incredibly strange and too acidic for sparging with. We're really not sure what caused this or why it happened, but we tipped out the sparge water we had prepared, and made a new batch with the same volumes, same water adjustments and the same relatively small amount of phosphoric acid (~0.4mL) and we got a pH of 5.93 which was exactly where we wanted it. I'm not able to explain what happened initially with the sparge water but we got it right in the end, so moving on!

We have a tendency to not heat up our mash water hot enough, so we get a fairly significant drop in temperature after doughing in - and even with recirculating it can take some time to come up to our target mash temperature. We ended up having to adjust our BrewZilla to over 75°C to get it reading 65°C at the top of the grain bed. West Coast IPA's are meant to be dry and ferment out fairly heavily, so we're not too concerned about having some extra fermentable sugar created from a lower mash temperature, but we really need to remember to adjust our mash in temperature so it's much higher to try and avoid this for future brews.

If you're using a BrewZilla, you should definitely get a long probe thermometer you can stick in the top of the grain bed so you can measure the temperature of your mash more accurately.

We would have liked to include rice hulls in our grain bill to help aid with recirculation, since wheat malt and toffee malt are known to create a thick, sticky mash. Unfortunately 41 Pints were out of stock so we had to make do without them, which lead to a fairly slow recirculation during the mash. You can see from the image below the tiny trickle we were restricted to for recirculation.

 

We stirred the grain bed a few times during the mash to try and help increase efficiency - but it was slow going. Unsurprisingly when sparging the drainage was also very slow and required a fair amount of stirring to coax the water through the grain bed. Rice hulls really are a game changer here - I normally use them so haven't had to deal with a slow/stuck for quite some time.

Moving on to the boil - and our pre-boil gravity reading shows we're bang on our expected target of 1.061. It's always a nice feeling to hit your numbers. The yellow refractometer pictured below is our AliExpress Digital Refractometer which we're finding after a bit more use is more accurate than we initially gave it credit for.

Whilst waiting for our BrewZilla to reach a boil, we measured and weighed out our hop additions. We've got a mixture of Citra, Centennial and Chinook hops for this one.

Hops were added as per the recipe into our hop spider with 15 and 10 minutes remaining in the boil. 

We then had a decent whirlpool hop addition for 15 minutes at 80°C to help extract a little more bitterness, but more of the desirable piney and fruity flavours from the hops.

After our whirlpool/hop stand, we continued to chill using the standard BrewZilla immersion chiller, before transferring to our Keg King PET Apollo Fermenter.

Gravity readings on our digital refractometer and good old floating hydrometer showed an OG of 1.066/1.065 - bang on what our recipe predicted. Colour looks amazing too.

We then pitched 2 packets of US-05 yeast and waited for the fermentation to begin!

There was a sizeable amount of trub in the fermenter as you can see from the picture above.

A gravity reading after a week of fermentation showed we had reached our target FG of 1.012

And lastly the graph from our fermentation using our RAPT Pill

Blue line = Temperature

Red line = Gravity

Green Line = Alcohol Content

As you can see fermentation was fairly steady and reached terminal gravity in just a couple of days before a soft crash (11/22) for dry hopping and finally the cold crash.

You can see after our cold crash has been completed we've got quite a bit of trub in the bottom, with a layer of yeast and then the dry hop charge sitting on top. 

The other larger white section at the top is a thin layer of yeast that has stuck to the fermenter wall during cold crash and didn't make it all the way to the bottom.

We transferred under pressure into a corny keg - initial taste is very promising and appears to have turned out very well, but we'll give it a couple of weeks to condition and fully carbonate before doing a full tasting review of this one.

Check out our Tasting Results and Review for this brew!

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West Coast IPA - Recipe (All Grain)

Following on from our recently published West Coast IPA Recipe Creation Guide - here's our go-to West Coast IPA recipe. Follow the link at the bottom of this article for a brew day run down.

West Coast IPA - Recipe Creation Guide

Style Overview

West Coast IPA is a sub-style of the American IPA (21A in the BJCP). It isn't documented as it's own official sub-style meaning there's plenty of room for interpretation for brewers - though there are some generally agreed on features that make up a West Coast IPA which we'll cover in more detail below.

The style originated in the 1990's, with brewers on the West Coast of the USA pushing the boundaries of hop additions in their beers - increasing hop bitterness and supporting malt bills significantly from the "regular" IPA's available at the time in what became a hop bitterness "arms race".

Popularity has varied over the years and the West Coast IPA has been facing stiff competition in recent years with the surge in popularity of other aggressively hoppy styles such as the New England IPA (NEIPA) or Hazy IPA.

There are three key things a West Coast IPA should have. Distinct bitterness, a dry, crisp finish, and loads of hop aroma and flavour.

Appearance

The appearance of a West Coast IPA closely matches the American IPA style - colour ranging from medium gold to light reddish-amber. Ideally it should have high clarity, though heavily dry-hopped and unfiltered versions may be a little hazy. Medium sized white to off-white head with good persistence.

Aroma

West Coast IPA's are all about the hops and should showcase new world American hop varieties that exhibit citrus, floral, pine, spicy and resinous notes. Grassiness should be avoided. A low to medium-low clean, grainy-malty aroma may be found in the background but should not be prominent or distract from the hops. Some dankness from yeast and hops is also acceptable.

Flavour

As with aroma properties, the flavour of West Coast IPA's is incredibly hop forward. Bitterness should be high with malt flavour low to medium. Some light caramel or toasty flavours are acceptable but should be kept to a minimum so as to not take away from the hops. Finish should be dry with low levels of residual sweetness. Some dank or weed-like aromas are common and acceptable.

Mouthfeel

Medium to medium-full body. Medium to medium-high carbonation. No hop derived astringecy. Light, smooth alcohol warming is not considered a fault so long as it doesn't intrude into the overall balance of the beer.

Vital Statistics

• ABV: 6% - as high as you dare to go
• IBU: Minimum 50
• SRM: 10 - 17
• OG: Minimum 1.056
• FG: 1.008 - 1.010

Malts/Grains

• Base Pale Malt - 80-90%
• Munich/Biscuit - 1% - 10%
• Crystal Malt - 1 - 5%
• Wheat Malt - 1 - 5%
• Dextrose/simple sugars - 1 - 10%

A base pale malt will make up the majority of the grain bill - regular 2 row is common but can also be substituted in part (or completely) for varieties such as Golden Promise or Marris Otter to add some more complexity. Lighter base pale malts like lager or pilsner malts can also be included as part of the base pale malt component.

Munich malt is optional and can be added at values up to 10% for some additional malt flavour and complexity.

Light to medium coloured crystal malts are common to add some darkness and residual sweetness but should be added at no more than 5% of the total grist.

Wheat malt is optional and can be added in small amounts up to 5% to help improve mouth feel and promote head retention.

Straight up simple sugar or dextrose can also be added up to 10% to help boost alcohol content without adding too much depth or additional malt character to the beer. Inclusion of dextrose can also help promote the dry finish that is required. Don't add more than 10% dextrose though as this can lead to  hot ethanol flavours which are undesirable.

Hops

Hops are typically added at the beginning of the boil (60 or 90 minutes) for bittering, with later additions being added at any or all of 15, 10, 5 and 0 minutes for flavour and aroma. There should be a decent bitterness charge added at the beginning of the boil to provide the high level of bitterness required for the style.

30 minute additions are redundant and should be avoided (unless you're doing a 30 minute boil instead of 60 minutes) which is becoming increasingly common.

New world American hop varieties should be used including (but not limited to) Cascade, Centennial, Columbus, Chinook, Citra.

Hop amounts are typically doubled from what is seen in a standard American IPA.

Whirlpool Hop Additions

Whirlpool hop additions are also optional but can certainly be done to help impart even more hop flavour and aroma in addition to (or instead of) late hop additions to the boil. Typical whirlpool hopstand would be for 10-15 minutes at approx 80°C.

Dry Hopping

Dry hopping should be aggressive to help promote the required hop flavours and characteristics of the style. Aim for no more than 3 days total contact time for your dry hop additions.

Mash (Temperature & Time)

Mash @ 65°C (to create a highly fermentable wort to leave promote a high attenuation and dry finish)
Mashout @ 75°C for 10 minutes

Yeast

Go for a neutral American style yeast. Some popular/common options are below

Liquid

• WY1272 American Ale II
• WLP 001 Californian Ale

Dry

• Mangrove Jacks M36 Liberty Ale
• Fermentis US-05
• Lallemand BRY-97
  
  

Water Profile

As with any beer, water is an essential ingredient and should not be overlooked. In general terms, a water profile that has elevated sulfate levels should be used for this style of beer to help the hops shine and promote the dry finish on the palate. Brewfather's "Hoppy" water profile is a good baseline to start from. Aim for a sulfate to chloride ratio of around 2:1.

Fermentation Temperature

Begin fermentation at the lower end of the yeasts recommended temperature range - fermenting at a lower temperature  helps to promote a clean flavour profile and reduce the risk of off flavours developing. After at least 5 days of fermentation, begin raising the temperature 1°C per day for 3 days (for a 3°C total increase in temperature). Raising the temperature towards the end of fermentation helps the yeast clean up after itself and is often referred to as a diacetyl rest.

Pressure Fermentation

Pressure fermentation can be beneficial for this style of beer as fermenting under pressure will help to suppress any off flavours from being created. Typical pressure used is around 10psi.

Cold Crashing

Cold crashing can be beneficial to this style of beer as it can help the hop debris settle to the bottom of the fermenter with the rest of the trub which in turn helps improve the clarity of the beer.

Sample Recipe

West Coast IPA Recipe (All Grain)

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