I periodically brew small (1-3) gallon all grain batches of beer on my stove top.  Some reasons I do that… 1.  The weather – it’s too cold, too hot or too something else, 2.  Time or 3.  I want to test something.  It’s a fun, simple, quick and economical way to brew all grain with minimal investment.

For the extract brewer, what kind of gear is needed to accomplish this amazing feat?  A comprehensive list follows…

1.  A Bag.

That’s about it.  You kind of just need a bag.

I started out with a paint straining bag from my local hardware store (similar to these).  I have since graduated to a small sized Brew Bag – review.  This process assumes you already have a reasonably sized kettle that you’ve used for extract brewing and a thermometer.

What is All Grain Brewing?  In a (very small) nutshell…

• Soaking malted grains at a set temp using a set amount of water.  This triggers enzymes that convert complex carbohydrates to simple, fermentable sugars.
• Separating those grains from the sugary water, now called wort.
• Rinsing to retrieve some of the additional sugar that remains on and in the grains.

Small Batch Brew in a Bag (BIAB) Step By Step:

• Decide on a recipe and a batch size and gather your ingredients.  Buy your grain pre-crushed if you don’t have a mill.  More info on recipe sizing below.
• Heat the right amount of water to the correct temperature.  How do you figure that out?  Use the spreadsheet below.
• Put an appropriate fine mesh bag in your kettle.  Make sure the bag is large enough to hold your grain.
• Put your crushed grain in the bag inside of the kettle.  Mix everything well and take a temperature.  The mash should settle out around your target temperature.  If it’s a little low, add some direct heat and stir.  If it’s a little high, add some ice and stir.  Your temperature does not need to be exact.
• Put the lid on your kettle and wait, usually 60 minutes, depending on the recipe.  Your grains are mashing.  Because there is no insulation, I usually take a temperature measurement halfway through and add a bit of heat to bring it back up to the right temp.  Again, always stir when you are adding heat.
• When the mash time is up, grab the bag and lift it out of your kettle.  I give it a spin or two to close up the bag.  Let it drip for several seconds.  I also give it a few light squeezes.  Have a large bowl nearby ready to receive your bag of spent grain.  When you have the time, discard the grains and rinse out the bag.  It’s ready for another use!
• Start boiling!
• I chill small batches in an ice bath in my kitchen sink.  Always use extreme caution when dealing with hot and boiling liquids.
• When you’re done you have a single vessel to clean!

You will notice, there was no rinsing of grains.  The technique that I’ve outlined, is a no sparge method.  You’re just losing a little efficiency.  No big deal in my book.  If you want to make up for that, you can figure out your efficiency and adjust by adding a big more base grain or DME.

The Spreadsheet:

(Click the graphic to enlarge)

This is a simplified version of my regular brew day spreadsheet.  Green cells are to fill in as necessary.  Blue cells are calculated values.  The directions section is calculated as well and puts all the numbers into narrative directions in plain english.

Need More?

My brew day spreadsheet helps you calculate water volumes and temps and helps you do simple tracking.

If you’re looking for a powerful, full featured solution for building recipes, brew day tracking and loads more, consider Brewfather.

• Hands on Review: Brewfather App – Recipe Formulation, Calculators & Brew Day Tools
• Brewfather offers a free full feature trial.  After the trial period, you’ll still have access via a limited, non-expiring account

Plug in your numbers under “Beer Info” and go.  You can adjust grain absorption rate and boil off rate, in the constants section, if you know your numbers or just leave the default values in place and adjust as you figure those out.

Microsoft Excel Version
Open Office Version
Google Docs Version (Thanks to Google+ friend Daniel for this!)

How do you get an appropriately sized recipe?

1. Use a recipe software like BeerSmith or Brewfather to scale recipe volumes down.
2. Divide a 5 gallon ingredient kit down to whatever size you need.  Want to brew a 2.5 gallon batch, Divide your 5 gallon recipe in half.  Want to brew a 1.25 gallon batch? Divide your 5 gallon recipe in quarters.  If you’re physically doing this with a recipe kit, make sure the grain is mixed up thoroughly to evenly disperse specialty grains.
3. I’m coming at this from a small batch perspective, but there’s nothing saying you couldn’t do this with a 5 or 10 gallon batch.  You just need get the right sized kettle and bag.