Monday, February 21, 2011

Imperial Oatmeal Stout

I'm taking names! That's right - I'm taking names on what this Imperial Oatmeal Stout should be called. (it's an "imperial" because of it's projected alcohol content (ABV) of approx 8%). Leave me a comment or shoot me an email to weigh in on your naming suggestion! This should have a thick malty body, with velvety chocolate and some roasted flavors. We'll see how it turns out. There are pictures at the bottom of this post.

In my previous post, I discussed my new plate chiller design and set up. This was the first batch I was able to put the plate chiller into use. My primary objectives were to decrease the amount of time to chill the beer, which should help to clarify the final product and lock in flavor/aroma. There were actually a number of new techniques (for me) that I employed on this brew:
1. Re-built my filter in my mash tun and installed a ball valve on the drain line
2. Plate Chiller with pre-chiller
3. Added Irish Moss to boil to clarify final product
4. Whirlpooled to clarify and prevent sediment from clogging plate chiller
5. Built and used a hop bag to hold the hops during the boil
6. Used a different yeast strain (Safale 04 instead of the 05 strain I used on all previous brews)
7. Blow off tube on primary fermenter

I was very pleased with the outcome of every new technique (although I won't find out about item #6, the different yeast strain, for a few more weeks.) Here's the reader's digest of what I'll dig into below:
Everything went very well, the several steps I took to clarify the beer (Items #2, 3, 4, 5) all worked extremely well, and I can see the wort is very clear already).

Let's look at each one:

1. Re-built my filter in my mash tun and installed a ball valve on the drain line:
I replaced my filter with actual stainless steel, rather than the synthetic (which I thought was SS), and added a ball valve to better control the flow from the mash tun. It worked beautifully! I was able to mash out in about 10-12 minutes in a very smooth manner and eliminated the "hot-side aeration" that I was having to do on my 2 previous brews.


2. Plate Chiller with pre-chiller
I've already discussed the set up of the chiller in this post. This set up worked very well! I was able to cool the wort from boiling temperatures to 68 degrees in 30 minutes (as opposed to 1 hour previously). This also kept the system closed which helped keep air from reaching the wort. I made my own in-line thermometer to monitor the temp of the wort as it entered the fermenter with a piece of 6" copper and a stick on thermometer for $2.25 instead of paying $30 for the fancy brand name Blichman "Thrumometer". It wasn't pretty but it performed great!

3. Added Irish Moss to boil to clarify final product
Irish Moss is algae from the North Atlantic that helps clarify the final beer product. I just rehydrated a table spoon and tossed it in the end of the boil.

4. Whirlpooled to clarify and prevent sediment from clogging plate chiller
I swirled the wort for a few minutes which drove all the sediment in the beer to the center of the kettle, away from the drain line. 

5. Built and used a hop bag to hold the hops during the boil
This is the piece of equipment you'll see sitting on top of the boil kettle (4" PVC with a 5 gallon paint strainer bag clamped onto it). All the hops get thrown in here, and the bag is pulled out at the end of the boil. Again, this helped eliminate sediment from the final product.

6. Used a different yeast strain (Safale 04 instead of the 05 strain I used on all previous brews).
This should help enhance the malty character of the beer - we'll see how it turns out.

7. I put a blow off tube (see second to last photo below), to prevent the krausen (foam head) from spewing out like it did on the Damn Chizzam double IPA. So far it hasn't gone over, but it's working perfectly nonetheless. 

Mashing the grains

My shiny new ball valve on my mash tun

Mashing out (and my new ball valve on the kettle)

Hop bag

Boiling wort and stirring away

Mashed grains



My ghetto, home-made mash stirrer (but hey! it work's great!)

My new plate chiller with pre-chiller in action

Close up shot of plate chiller and pre-chiller. Plate chiller is on the chair, and the pre-chiller is in the bucket.


Finished wort. Crystal clear.

Imperial Oatmeal Stout wort is in primary fermenter. I used a blow off tube this time, just in case the krausen (foam head) decided to go crazy and overflow like it did on the double IPA. (The double IPA is in the plastic bucket - secondary fermenter - dry-hopping.)

2 comments:

  1. Just read this now off your popular posts list. Do you have a photo of the filter on your mash tun? I'm thinking about using a plate chiller, but have heard you really need to take precautions to minimize the amount of trub and hop residue that flows through it, which it sounds like you have.

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    1. I don't have a pic handy, but in the mash tun I use a stainless steel braided hose connected to plastic tubing. You just have to remove the inner tubing that is inside of the braided hose. It works really well. I have a 1/2" line on my small mash tun and a 1" line on my larger one. I don't use a filter on my kettle. I generally whirlpool and let it stand for a few minutes after whirlpool and I don't pick up too much trub. I would like to get a pick up tube that will collect the wort from the side of the kettle though.

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