PICOBREW The home of small scale home brew...


Q: What is Picobrew? 
A: Making real homebrew easy for everyone from all grain (not kits) in easy to manage one gallon batches...
Q: Why would you want to do that?
A: For many reasons:
  • TIME - 5 gallon batches used by homebrewers typically take 8+ hours to brew, 1 gallon can be done in half the time
  • SPACE - lots of bulky containers to store (even when not full of lovely ale) - you can even make home brew in a tiny apartment!
  • SAFETY - Big pots of boiling water and kids / animals aren't compatable - brew your beer safely on the cooker
  • EXPERIMENTING - Got a crazy idea or recipe? Does it matter if a single gallon of ale fails to meet expectations?
All four of these reasons were my motivation to develop PICOBREW. I have been a home-brewer for years using standard 5 gallon home brew equipment, but I have been absolutely delighted at the results of my miniaturisation experiment. I now want to share my experiences with you, so you can join me on my PICOBREW adventure. On this page you will find all the information that you need to mash, sparge, boil, ferment, bottle or keg your own all grain home brew - all in easy PICOBREW one gallon home brew batches. Happy brewing!


This was undoubtedly the biggest challenge I faced once I had decided to PICOBREW. I scoured the internet looking for bits of kit that would do the job. Eventually, I found what I was looking for. It all started when I stumbled over the excellent mini-keg system which allows you to keg 5 litres of beer at a time. The challenge now was to put together a mash tun, boiler and fermentation system which would complement the mini-kegs. The inspiration came from an unusual source: chinese slow cooking, thermal cooking to be exact. This is actually a very old means of cooking where food is brought to temperature before the pot is transferred into a 'nest' of insulated material where it is then left to continue cooking for several hours. Traditionally, hay was used as the insulating material (the term 'haybox' is still used today), but modern thermal cookers now consist of two pots; a stainless steel inner pot and a twin walled outer pot with a vacuum between the walls.

Hence, buy a thermal cooker and you have just bought an exceptionally efficient mash tun (inner pot nested in outer pot) and boiler (inner pot) - all in one very compact package. Furthermore, when not being used for brewing beer, you have a magnificent slow cooking solution for your casseroles, soups and stocks!

The remainder of the equipment is easy. Small fermentation bins are common place, thanks to those mini-shot kits which are now available at your local home-brew shop. All you need now is a long handled spoon, thermometer, mashing and sparging bag, a siphon and whatever finishing kit you need (depending on whether you choose to bottle or keg). For a full list of what and where to buy, see the bottom of this page.

Now, let's do some brewing!


What follows is a step-by-step guide of how I make my basic ale. I have assumed some brewing knowledge, but if you are completely green to home brewing, I do recommend Graham Wheeler's book on the subject:

First make sure everything is clean. Place 5tsp of steriliser into the inner pot of the thermal cooker and top up with luke warm water (Image 1). After 10 minutes, transfer the sterilising solution into the fermenter and submerge all other utensils to be used (Image 2). Meanwhile, place the inner pan of the thermal cooker containing 4 litres of cold water on the stove (Image 3). Next, weigh out the grains. For my basic ale, I use 1kg of Pale Malt (Image 4).

This is based on BIAB (Beer in a Bag - as known in the trade!). Line the inner pot of the thermal cooker with the mashing and sparging bag (Image 1), and bring the 4 litres of water to strike temperature - 77C (Image 2). At this point, turn off the heat and add the grain (Image 3). Make sure all grain is fully submerged and that the temperature is at the correct starting temperature - ideally 67C, give or take a couple of degrees. If all is well, add the inner pot lid and transfer the inner pot from the stove into the outer pot (Image 4). Close the outer pot lid and leave for a minimum of 60 minutes to mash. This is where the thermal cooker comes into it's own. Over this period, the temperature will barely change in the inner pot, so feel free to leave the mash for as long as you wish, safe in the knowledge that all that starch is being efficiently converted into sugars. Meanwhile at this stage, I find it useful to wake up the yeast. Put a full kitchen kettle on the boil. In a small sterilised container, add a couple of teaspoons of spraymalt to a small measure of boiling water from the kettle; keep the rest in the kettle - you need that for sparging later. Once the starting solution has cooled to 20C (Image 1), pitch the yeast from the sachet. Cover with tin foil to avoid any contamination.

After an hour, it is time to sparge. In the PICOBREW process, I use the old method of re-mashing which I have found to be more than adequate. To do this, move your sterilised fermenter close to the thermal cooker (Image 1). As you lift the mashing bag, most of the wort will remain in the inner pot (Image 2), but you may wish to find a way to collect the drips in the thermal cooker before transferring the mashing bag into the fermenter (kitchen cupboard handles come in handy at this point). Transfer the mashing and sparging bag into the fermenter and carefully add 1.5 litres of near boiling water (80C) from the kettle (Image 3). Leave for 15 minutes before removing the bag (Image 4), add the re-mash to the wort in the inner pot.

Move the pot onto the stove and get the boil going (Image 1). This needs to be as vigorous as possible but it will need watching carefully if you don't want sticky wort over your cooker. Beat back in any froth that appears. Once a good rolling boil is achieved, add the hops. Again, watch carefully and DO NOT put the lid on. You are aiming for a good 60 minute rolling boil from this point (Image 3). After 45 minutes, add the Irish Moss and any late hops if required (Image 4). Notice that the volume of the liquid will reduce dramatically. This is OK as we will top up with water later - you will probably be left with around 2 litres of wort at the end of the boil. However, if alarmingly large quantities of wort are being lost to evaporation, then do reduce the heat a little.

After the 60 minutes has elapsed, turn off the heat and leave to settle. Assuming the boil has been long and vigorous enough, then the trub should stick together nicely and start sinking to the bottom of the inner pot (Image 1). Leave it for around 15 minutes to do this. Next place your fermenter in the sink. Using your kitchen sieve as a strainer, gently tip the contents of the inner pot into the sieve to separate the trub and hops from the wort (Image 2). At this point, you will realise just how much wort has been lost to evaporation - don't worry (Image 3). We now need to crash cool the wort. This process normally takes a significant period of time in traditional home brewing, but in PICOBREW, all you need to do is fill the sink with cold water and the wort will cool rapidly (Image 4).

Once the wort has cooled to around 25C, you can top up the wort to 5 litres with cold tap water (Image 1). Do not be tempted to do this to crash cool the wort as it will impair the final beer. It is now safe to pitch the yeast, so tip in the whole of the starter solution made earlier - it should be bubbling away nicely (Image 2). Now we just need to let nature take it's course. Loosely fit the lid to avoid any nasties from getting in the beer and leave. The fermentation will first bubble lightly, before forming a crust (Image 3), from which bellows of foam will emerge (Image 4). After this, the fermentation will slow considerably. Be patient, take hydrometer readings if you wish, but a 7 day fermentation at room temperature is nearly always spot on for average strength beer.

As my original inspiration for this was mini-kegs, that is how I choose to finish my PICOBREW. Using the change in height between the kitchen sink and nearby worktop, simply siphon off the beer into the keg (Image 1). I use one of those new auto siphons which I think are fantastic and minimise the chances of contamination. Next, prime the beer using spraymalt (1 teaspoon per litre is fine) and seal with the supplied bung. If you prefer to bottle then that is equally easy, just get a good bottling tap to connect to the end of the siphon. It is now all about patience. Leave it for as long as you can (at least 14 days) before tapping the minikeg (Image 3). If you are a purist and prefer not to use a CO2 tap with your beer, then hand pump variants are available. Finally, enjoy the fruits of your labour (Image 4).


Almost any homebrew recipe can be scaled down for PICOBREWing. As most recipes call for standard 5 gallon brewing equipment, it is often just a simple case of dividing all ingredients by five. To get you started, here is the tried and tested recipe that I use myself for my standard ale (above). I will add more in due course...

1kg Pale Malt
25gms Goldings Hops (boil for 1 hour) - you will need micro-scales to measure (see below)
Half teaspoon of Irish Moss (add to the boil at 45 minutes)
Spraymalt to finish

Starting Gravity: 1045
Final Gravity: 1011
Approx. ABV: 4.6%


Making beer isn't my career or vocation. It is just a hobby and something I feel passionate about. Making good ale at home is easy and anyone can do it. The satisfaction of savouring a unique brew which you have lovingly crafted for the enjoyment of others cannot be underestimated. Furthermore, you control the quality of the ingredients and production. For me, nothing beats it! If you would also like to join me on my PICOBREW adventure, here is a list of all the kit you need to brew great small batch beer at home.

First and foremost, the most important thing you need to buy is the thermal cooker. The one I have (and strongly recommend) is this one:
6.8 litre Thermal Cooker. It is easily the biggest available on the market and is tried and tested to be up to the job!

All the other bits and pieces can be picked up from amazon.co.uk or your local home-brew shop:
If you prefer to bottle rather than mini-keg:
And finally, ingredients:

Enjoy! Any questions, queries, comments, whatever to lee@wetroads.co.uk


The Home Brew forum - The forum where I post my musings
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