With my previous successes in Extract and Extract with Special grain brewing, I decided it was time to take this hobby to the next level and try my hand at a partial mash. For those not sure on what partial mash brewing is I will give you a short description:

Like Extract brewing with special grains, you are using both malt extract and grains to produce a beer. Unlike Extract with specialty grains, where you simply steep the grains to create a sort of “grain-tea” you use in the water, with Partial Mash you are actually converting the grains into an wort of their own. This process requires much more diligence and patience then the extract brewing as water temperature is critical to get a good conversion.

Unfortunately this time around I did not have much of either and this brew session blew up in my face. Lets look over what I did and where I made my mistakes.

Bradinator’s Chocolate Oatmeal Stout

Ingredients -

Extracts

• 3.3lbs of Coopers Real Ale LME
• 2.25lbs of Light DME (around 4 and 1/2 cups)
• 1.0lbs of Dextrose Sugar (2 cups – for additional body)

Grains

• 1.5lbs of Quick Oatmeal
• 0.25lbs of Chocolate Malt
• 0.5lbs of Roasted Malt

Extra Required tools -

• Mash Tun (Pot #1)
• Sparging Pot (Pot # 2)
• Brewpot
• Sieve/Grain Bag

Steps -

1) In a pot #1 bring about 1.5L of water per lbs of grain to around 70c. Add the grain and mash for 45 minutes at a constant temperature. This is your mash tun and mash.

My mistake – I brought approximately 4L of water to 70c and added my grains in a grain bag. When I decided that the grain bag was not actually preventing the grain from escaping I removed the bag and began mashing the beer freely in the pot. I really struggled to keep the temperature at 70c, finding it dropping to 65c and going to about 75c during the 45 minutes of mashing.

What I could have done better – For starters I should invest in a good reusable grain bag. Secondly I need manage my water temperatures a lot better. Finally I need to get another large pot so I can free up my brew pot.

2) In pot #2 bring another 1.5L per lbs of grain to around 80C – This is your sparging water.

3) Place a large strainer/sieve over your brewpot and pour your mash into the brewpot, catching the loose grain in the strainer and allowing the wort you create to drain into the pot. Pour your ~80C sparge water over the capture grain to free any additional wort.

My mistake - What didn’t I do wrong here? For starters I used my brewpot as a mash tun. You can do this if you use a grain bag, but its better to leave it free. So I poured my wort into a sieve sitting in a smaller pot, then attempted to sparge. Patience. Patience. Patience. I should have let to wort collect from the sieve for a lot longer, I should have very slowly sparged. Needless to say I made a monster of a mess all over the kitchen doing this.

What I could have done better - I think I am going to snag a few alligator clips from my office and use cheese cloth pinned over the brewpot to catch the grain next time.  Or just buy a huge sieve to place over the brewpot. Using my brewpot to collect the wort will save me a lot of headache and mess.

4) Top off the collect wort with water in your brewpot and bring to a slow boil. Remove heat and add your extracts and hops as normal.

My Mistake - How I screwed up here is beyond me. Its not like I have not done this over half a dozen times before. I bought the temperature up way to fast and burnt a little wort to the bottom of the pot.

What I could have done better – Bring up the temperature slowly to prevent the wort from burning to the bottom of the pot.

5) Return to boil and maintain a slow boil for 60 minutes.

My Mistake – Never, ever, EVER walk away from your brew. It only takes a moment to have a boil over. I walked away thinking that I was safe. This was the worst boil over I have ever had and I would spend the next hour cleaning it up.

What I could have done better - DO NOT WALK AWAY FROM THE BREW YOU IDIOT.

6) After the boiling is finished remove from heat and place in an ice bath. This time around I decided to try cooling the wort with cold water. I moved the hot wort into my fermenter and topped it off with cold water while monitoring the temperature.

Why I did it differently - At this point I was getting very frustrated and impatient with this session and I just wanted to put this disaster to bed as soon as possible. Cooling this wort with cold tap water worked well. I managed to get it to temperature (around 26C) in about 10 minutes. If the beer does not get an infection I will probably use this method again. I did not even both measure the water while I filled it up. I just took a gravity reading and saw it was good enough (1.046-1.048) and went with it.

7) Pitch the yeast and nutrients. Put on the lid and air bung. Your are finished. I did not even both rehydrating the yeast… And I forgot the Irish Moss. Again!

What a disaster. The whole process nearly took 4 hours from start to finish. I could not bring myself to call it an utter failure and abandon the entire session. According to Beersmith my OG should have been around 1.055 for a 5 gallon batch, but I got only around 1.046 which is substantially lower. I could only image my conversion efficiency must have been around 10%, but even with all the mistakes I made I doubt it was that low. So the low gravity is a mystery to me at this point.

I checked the beer this morning and it is fermenting. Whether in ferments into something good is still to be determined. I am going to give it 3-4 weeks in its Primary then straight into bottles for another week or so of conditioning. Pray with me to the beer gods; This ones going to need a miracle.