One Gallon Brewing: Setting Up an All Grain System -- Part 2 - Brain Sparging on Brewing


Sour beer, saisons, farmhouse beer, homebrewing, ramblings

June 10, 2013

One Gallon Brewing: Setting Up an All Grain System -- Part 2

In part one of this series I discussed a very basic primer on all grain brewing. If you are new to all grain brewing you should read the prior post in this series or another source on the subject so you understand what the hell I'm talking about in today's post. Today's post will discuss the typical homebrewer all grain systems, how they apply at the one gallon brewing level, and my person hybrid system. I'll start off discussing the basic equipment you will need/want/should have regardless of what system you decide to use. There are basically two ways you can put together a small batch all grain system: a traditional mash tun or BIAB (brew in a bag). I'll explain both and discuss their respective pros and cons. Then I'll discuss my hybrid system and why I find it superior than the typical two methods homebrewers employ.

Basic equipment all grain brewers need/want/should have

Certain basic pieces of equipment are helpful no matter how your brewing system is set up. These components are cheap and often you will have most of these pieces from your extract brewing. A few of these pieces I will suggest are optional but nevertheless worth having on hand. In no particular order, here are some pieces you should acquire for successful all grain brewing:

  • Vessel large enough to hold the mash
  • Kettle large enough to heat your full wort volume
  • Heat source to heat water and boil wort
  • Mash paddle/large spoon
  • Hydrometer or refractometer
  • Quality, calibrated thermometer
  • Digital scale measuring at least grams and ounces (for small batches you should obtain one that measures down to tenths of grams)
  • Grain mill (optional)
  • Ph strips or ph meter (optional, at least starting out)
  • Measuring cups (preferably large ones)
  • Timer
  • Heat-resistant, food grade tubing -- typically silicone (optional)
  • Brewing software (optional)
As you become more advanced in brewing you will want to pick up some of the optional equipment and/or buy better quality equipment. You don't want to waste money buying cheap equipment and then upgrading, especially when the difference in price is low. I would encourage you to spend the money on a nice digital thermometer because the floating thermometers are almost always several degrees wrong (mine is currently 13 degrees too cool). I'd also recommend looking on Amazon for a reasonably priced small scale that measures in tenths of grams. You'll need that preciseness when you start measuring brewing salts because small batches are going to use that small of volume of brewing salts (if you need to adjust your brewing water in the future). These scales usually run around $15-25, which is about what a cheaper kitchen scale will run you anyway. The grain mill, refractometer and some of the other equipment can be future purchases when you decide you want to focus on improving the details.

The traditional homebrewer all grain set up

Traditionally, homebrewers have worked with systems that emulated what breweries use. For that reason, the equipment used was small versions of the same equipment, using the same techniques and processes. If you recall back to the first part of this series, I discussed how the mash and sparge processes involved adding and draining water/wort from the grain. That is a practical issue. It's easier to move liquid with pumps (or gravity) and hoses than it is to move grain between vessels of hot water.

The common approach for the modern but traditional approach is a cooler and kettle set up. A large igloo-style water cooler is used as a mash tun (the insulation helps maintain temperatures) with the kettle serving as the hot liquor tank to heat mash and sparge water and then to collect the wort and boil. Many homebrewers use this system with a five or ten gallon cooler and batch sparge (although you could fly sparge). You can use this same approach on a small scale with a one or two gallon cooler (or a similar type of vessel that will retain heat). You want to use a vessel that is not too much larger than the volume of mash because the more contact the mash has with the air and non-heated surfaces the quicker it will lose heat and you will have more variability in your mashes. A two gallon cooler is small enough to get good results on a one gallon batch but will support mashes for two gallon batches except for very high gravity beers with large mash volumes.

The advantage with this system is that you have a mash tun with temperature stability and a fairly easy set up. The downside is that you will have to make a modification of the cooler to replace the water spout with a manifold that filters out the grain, so it does not clog, and safely pours hot liquids. Following the typical homebrewer's set up that could add a little bit of cash to your costs (in the tens of dollars at most) and you couldn't use the cooler for anything else. Another downside is that if you already have a few stock pots in the house you may not want to spend more cash on another piece of equipment or have the space for it. A two gallon cooler is not very large but in an apartment sometimes every square foot counts.

There are some variants used at a larger scale, such as direct-firing the mash on its own heat source in a kettle with a manifold to drain the wort. Very advanced systems use pumps to circulate the mash to maintain temperature stability but at a small batch level neither of these are particularly efficient.

Brew in a bag (BIAB) method

Brew in a bag is exactly what it sounds like. It works in reverse of a traditional mash, where the liquid is removed from the grains. Instead, the grains go in a bag and you move the grain bag between vessels to mash and sparge. For BIAB you need two kettles, one for the mash tun and one for the sparge. You will heat the mash water in the mash tun kettle and then add a strainer bag full of crushed grain to the kettle and let the mash do it's thing. You then heat the sparge water in the other kettle and when it is time to sparge you just move the grain bag from one kettle to the next and dip the bag in and out of the sparge water to rinse the sugars off the grain. Then you dump the grains out of the bag. Then mix all your wort together and boil.

For the small batch brewer this method has a big upside and a big downside. The huge advantage is that your equipment costs are minimal. For a small batch you can usually buy plastic strainer bags at homebrew shops meant for steeping grains (just don't tie it off so you can reuse it). For larger batches many people use paint strainer bags. If you own a set of pots and pans it probably came with a 1.5 gallon stock pot, which is definitely large enough for the mash on a one gallon batch. You already own a kettle from your extract batches, so that is fine for the sparge water. It doesn't matter if the kettle is too big for the sparge volume as long as you can dunk all the grains in the water and get a good rinse.

The huge downside is that it is much harder to maintain a consistent mash temperature. A stock pot will not keep mash temperatures stable on its own so you will need to monitor the temperature and keep it slightly heated on your stove or in your oven, if your oven goes down in temperature to mash temperatures. Most only go down to 170F, which is too hot. Personally I started out BIAB on my smaller batches but gave it up because I was tired of getting inconsistent mash results. I'd have mashes that got too cool then I overshot by adding too much heat. Many mashes went through periods too cool for what I wanted. So I gave it up. That's why I went with my hybrid system.

My hybrid system

My hybrid system takes the best of both worlds. I use a two gallon cooler as a mash tun but I did not modify the spout. Instead, I add heated mash water to the mash tun then use a grain bag to add the grains. The insulated cooler keeps stable temperature and I stick the cooler in my unheated oven to help trap any lost heat in a smaller area. When the mash ends I pull the bag and sparge in my kettle doing the BIAB dunking. Then I pour the wort from the mash tun into the kettle and get boiling. It's practically BIAB but without a kettle as the mash tun. I already had the grain bag from my prior BIAB attempts (but I think they cost like $2 for a 2-3 gallon nylon strainer bag). I also already had the kettle, so my only upgraded purchase was the two gallon cooler.

I use a Coleman two gallon stackable cooler, which runs about $11 on Amazon. It has improved the quality of my small batches a lot so I think it was $11 well spent. It holds up to warm temperatures ok although it is not as well insulated as my larger ten gallon cooler. By not modifying the spout I can use it for non-brewing purposes. It also fits in my ten gallon mash tun so I'm not losing any house space storing it that way. It would probably fit in your kettle so it won't take up extra space. Plus, once it is dry, you can store other brewing equipment inside it.

In the next installment...

In the third and last installment I will put together a walk-through, with pictures, of an entire one gallon batch brewing day. I will be brewing an all brett farmhouse-style beer. There's nothing advanced about the brewing process, it's going to be a straight-forward brew day but with brett fermentation instead of saccharomyces. Actually, it will be a brett primary fermentation and then a second brett strain is going in for a brett-on-brett fermentation. However, I'll post the recipe details in a separate post.


  1. Just wanted to say thanks for this series. I've only recently started brewing in one gallon batches, and it really is difficult to use a kettle as a mash tun and keep it at the correct temperature. I never thought to use a cooler as a mash tun. I ordered the one you suggested and am looking forward to trying it. Thanks again!

  2. Dude. You're a genius!!!

  3. About how much grain do you think you can hold in a 2 gallon cooler? like 4-5lbs?

  4. Five pounds at 1.3 qt/lb will max out this cooler

  5. Can you provide me a location to buy nylon bags?

    1. Many of the LHBS sell nylon grain bags for BIAB brewing or steeping grains for extract brews. These should be a suitable size for a 1-2 gallon batch. It's where I got mine.

      Some people also buy paint strainer bags at hardware shops. They are durable but not food grade. The ones at the homebrew shops are food grade so I would personally opt to spend another dollar to get the food grade product.

  6. I've been thinking about trying some 1-2 gallon batches and had considered the oven as the means to regulate mash temp.

    Would a 170 degree oven really bring up the temp of the mash much? It's only a 15-20 degree difference with no direct heat being applied to the kettle. I can't see it boosting the mash temp by more than a couple degrees, and even then you could kill the oven after 30 or 40 mins.

    1. Eventually it will raise the temperature of the mash up to 170 or close to it much in the same way setting the oven to 350F eventually brings your food to that temperature.

      Another consideration is that most electric ovens do not heat uniformly and you may have parts of the mash far warmer than 170 and other parts cooler. You might be denaturing enzymes on the bottom the mash and mashing too cool on the top.

      In my opinion neither is worth the risk.

    2. Thank you for the comments about using an oven. I hadn't thought of using my electric smoker for this purpose. It can maintain a constant 125 or 156 degrees with a 2 gallon pot in it. It even has digital temperature control.

  7. Hello! I recently did a 1 gallon mash and after an hour the temp dropped 10* degree or more. Any thoughts to keep it warmer, then just the oven trick?

    Could you provide me your beer smith equipment profile?

  8. This is a great article. It gave me a lot of useful information. thank you very much.