Shawn Hargreaves
Well-Known Member
I've been brewing for nearly three years now: one year with just extract and steeping grains, and since then using partial mashes. I'm pretty happy with my technique, so I thought I would write it up here in the hopes that it might persuade some other extract brewers to take the plunge and try their first mash.
WHY PARTIAL MASH?
Extract alone simply does not offer the range of flavors that can be obtained from fresh grains. Some types of grain (notably crystal and roasted malts) can be steeped, but this does not work for everything. If you want to brew with Munich, Vienna, biscuit, brumalt, aromatic or acidulated malts, or other grains such as wheat, oats, or rye, you need to mash.
Here lies a range of flavors that simply cannot be achieved in any other way. Think your IPA is good today with a handful of steeped crystal? Try the same thing but with a pound of Vienna. Or take your delicious nut brown ale, and add some biscuit malt alongside the crystal and chocolate...
WHY NOT ALL GRAIN?
I live in a small house, have no garage, and limited storage space. I brew in my kitchen. I do not have room for bulky equipment that cannot be reused for cooking food.
MY EQUIPMENT
When I am not brewing, the two plastic buckets can be nested inside each other, with the brewpot inside that.
The soup pan is only necessary because my brewpot is too big to fit in the oven. If I had a larger oven, I could use the brewpot for everything.
Since I already had the brewpot and bottling bucket when I was making extract brews, the only new expense for me to partial mash was the second bucket. This cost $15, and it took me 10 minutes to drill the holes.
MY PROCESS
The goal is to hold a mixture of grains and water at an exact temperature for an hour or more, so the enzymes from the malt will convert the starches into sugar.
After several attempts at doing this on the stovetop, by adding bursts of heat from the burner and various combinations of hot or cold top up water, I found the most accurate and stress-free way to maintain a steady temperature is using the oven.
My oven thermostat is nowhere near accurate enough to hit the right temperature, but as long as I get my water and grain to exactly the right starting temperature, placing a large exactly-right pot inside a nearly-right oven creates a low enough temperature differential that it can sit for the duration of the mash with no more fiddling required.
Here's what I do:
The limiting factor with this system is the size of my oven and soup pot, which can comfortably hold just under 4 pounds of grain. This is typically about half my target density, so I supplement it with a late addition of 3 to 5 pounds of extract. If I had a second soup pot, I could probably fit that next to my current one in the oven, but I haven't tried that yet.
WHY PARTIAL MASH?
Extract alone simply does not offer the range of flavors that can be obtained from fresh grains. Some types of grain (notably crystal and roasted malts) can be steeped, but this does not work for everything. If you want to brew with Munich, Vienna, biscuit, brumalt, aromatic or acidulated malts, or other grains such as wheat, oats, or rye, you need to mash.
Here lies a range of flavors that simply cannot be achieved in any other way. Think your IPA is good today with a handful of steeped crystal? Try the same thing but with a pound of Vienna. Or take your delicious nut brown ale, and add some biscuit malt alongside the crystal and chocolate...
WHY NOT ALL GRAIN?
I live in a small house, have no garage, and limited storage space. I brew in my kitchen. I do not have room for bulky equipment that cannot be reused for cooking food.
MY EQUIPMENT
- 4 gallon brewpot
- 2 gallon soup pan, with lid
- 5 gallon plastic bottling bucket
- Second plastic bucket, with 50 small holes drilled in the bottom
- Stove
- Oven
- Thermometer
- Measuring jug
When I am not brewing, the two plastic buckets can be nested inside each other, with the brewpot inside that.
The soup pan is only necessary because my brewpot is too big to fit in the oven. If I had a larger oven, I could use the brewpot for everything.
Since I already had the brewpot and bottling bucket when I was making extract brews, the only new expense for me to partial mash was the second bucket. This cost $15, and it took me 10 minutes to drill the holes.
MY PROCESS
The goal is to hold a mixture of grains and water at an exact temperature for an hour or more, so the enzymes from the malt will convert the starches into sugar.
After several attempts at doing this on the stovetop, by adding bursts of heat from the burner and various combinations of hot or cold top up water, I found the most accurate and stress-free way to maintain a steady temperature is using the oven.
My oven thermostat is nowhere near accurate enough to hit the right temperature, but as long as I get my water and grain to exactly the right starting temperature, placing a large exactly-right pot inside a nearly-right oven creates a low enough temperature differential that it can sit for the duration of the mash with no more fiddling required.
Here's what I do:
- Enter my grain list into Beer Smith, choose one of the Single Infusion mash profiles, and see what water volumes and temperatures it calculates for me.
- Preheat the oven to the target temperature, typically around 150.
- Measure out the desired water into my main brewpot, and heat this on the stove to the mash-in temperature (typically around 166). This must be measured as exactly as possible, which means regular stirring to make sure the heat is evenly distributed. Be careful, as the temperature increases faster the hotter it gets! It will sit for ages around 100, then shoot up once it gets past 130.
- Once the oven is warm, place the soup pan and lid inside it to preheat them. Don't leave them in too long, though, as they will end up hotter than intended (because metal absorbs radiant heat more easily than the air which is measured by the oven thermostat). This doesn't need to be exact: just get the pan and lid warm to the touch so they won't throw things off.
- Place crushed grains in the warmed soup pan.
- Pour in the measured and carefully temperature controlled water.
- Stir, then insert thermometer.
- If temperature is not exactly right, add boiling water or ice cubes to correct it (hint: it is better to err on the side of slightly too warm, as ice cubes have a greater temperature differential, so it is easier to cool things down than to heat them up).
- Place lid on soup pan. Place pan in oven. Close oven door. Wait.
- Remove pan from oven every 15 minutes to stir the mash. Do this quickly to avoid losing heat. You may also wish to check the temperature and make any necessary corrections via boiling water or ice cubes, but I have found this system to be so stable that I no longer bother measuring after the initial strike.
- While waiting, warm a second quantity of water, using the main brewpot on the stove.
- After an hour, remove pan from oven.
- Place plastic bucket with holes in the bottom inside regular non-holey bottling bucket.
- Pour grain + water mix into the inner bucket.
- Slowly lift the inner bucket, while sprinkling warmed water over the grain bed.
- Hold until there is no water left and wort stops dribbling through the holes.
- Pour wort from bottling bucket into brewpot, then proceed as normal (add bittering hops, boil, late extract addition to boost gravity, add finishing hops, cool, pitch, ferment, bottle, drink, hangover, unfortunately have to go to work in spite of hangover, return home, drink more, etc).
The limiting factor with this system is the size of my oven and soup pot, which can comfortably hold just under 4 pounds of grain. This is typically about half my target density, so I supplement it with a late addition of 3 to 5 pounds of extract. If I had a second soup pot, I could probably fit that next to my current one in the oven, but I haven't tried that yet.
I haven't drank the beer since it is still in the fermentor, so I can't comment on the quality comparison, but the process was enjoyable.
