Although brewing small batches has it’s advantages, one task that can prove more difficult is the mash. Although there are variations in this step with different recipes, generally it’s required to keep the grains at the same temperature for an hour. The smaller the mash size, the harder it is to maintain temperature. My first brew I tried to keep temperature on my cook top, and if you’ve ever done the same, you’ll understand how tedious it can be 😑 I couldn’t find much information on mashing small batches when I started out, so here are the successful methods I used….
This is probably the easiest and most convenient way to mash, and no extra equipment required. Firstly empty your oven, including all the racks and just check that your brew pot will fit inside. At least 10 mins before you start your mash, turn on your oven on high (I put mine at 220C). when you’ve got your mash to the correct temperature on your cook-top, turn the oven off and place the mash with lid on in the oven. Leave the door of the oven slightly open for around 2 mins, then close the oven and leave it, the residual heat of the oven should keep the temp of your mash quite well. I usually take the mash out after 30 minutes, give it a good stir, turn the oven on again and repeat the process. This method works for me and keeps my mash temperature very stable. Of course all ovens are different, so you may have to adjust a little. I’ve heard of people leaving their oven on the lowest possible setting the entire time, I cant do this as I’ve got an old 70’s over with a heating element, so lowest is too hot. With any oven, and a small amount of experimentation, you should be able to achieve a consistent mash temperature.
One of my first few blogs was the DIY Mash Tun, I’ll be deleting that blog as I write this one because I want the information I share to be practical and useful. At the time I wrote the DIY Mash Tun blog I was still a bit caught up in all the brewing paraphernalia, as you can see below I went overboard, just the container itself is really all you need.
A mash tun is basically an insulated container intended to keep your mash at the desired temperature. I’ve seen examples of mash tuns were heating elements have been added in case the mash cools, but with BIAB small batches this isn’t practical as you’ll probably end up burning the bag or your grains. Without the ability to heat, it’s important to keep the mash tun well insulated, so choosing at appropriate size mash tun in proportion to the size of the batches you brew is important. I’d suggest that for 5 litre batches, a container 8-10 litres is ideal. My original mash tun was the 7.5 lire although a great size and cheap, the insulation was a little thin, and the lid isn’t insulated at all. I used a heated grain bag underneath, created a foam insert to stop heat escaping from the lid and wrapped it well with a thick blanket when mashing. I’d lose 1-2 degrees in an hour which I think is acceptable. For value for money and ideal size, if I had my choice again, I’d go with the Willow 10 litre, it’s $40 from Big W. I can’t recommend this product though as I haven’t used it myself.
The great thing about mash tuns is that they’re set and forget, once your mash is in there and all sealed up you can relax and do what you like. It’s often suggested to stir your mash occasionally, instead I just shake the mash tun around a bit to avoid losing heat from opening. The challenge is getting your temperature right and maintaining. I always have my strike water temperature (the water the grain will go into) a couple of degrees higher than the recipe indicates, that way when you add the grain and the temperature drops, you’ll have a minute or two to give the grains a good stir before you hit your mash temperature. Another tip is to pour your strike water, at boiling temperature, into you mash tun, then let the water cool to strike temperature before adding the grains. This allows for your mash tun to warm up, and therefore maintain temperature more effectively. Cover tightly with a thick blanket, sleeping bag or similar. Also sitting your mash tun on a heated grain bag (like a hot water bottle but with grains you heat in the microwave) is helpfully at maintaining temperature.
This is a mash method I think I may have invented…although I’m sure someone else would have done similar before. It came about when I purchased a new mash tun, but being a 17 litre mash tun, it wasn’t good at all for maintaining temperature of small mashes. However after discovering one of my smaller stock pots slid nicely into the opening, light bulbs went off in my head💥 and the Bain-Marie Mash was born. I simply pour the amount of sparge water I need (usually around 5 litres) at boiling temperature into the mash tun. My small stock pot with the mash then slides in over the top and the boiling water underneath maintains the temperature. I then just take the lid off the stockpot or cover with a blanket to increase/ decrease temperature, it works quite well with not much need for adjustment. Then when the mash is finished the sparge water underneath usually cools close to the temperature required. Although you may not use this method, I hope I’ve inspired you- it pays to think outside the box and get creative!
SOUS VIDE MASH
This is one technique I have not tried myself, but seems very popular, with good feedback from other brewers. Sous vide means “under vacuum” in French. It’s the cooking technique of sealing food usually in plastic and heating it in a water bath at precise temperature. In recent years a number of Sous Vide Cooking Sticks have come on the market. Basically you just stick it in your pot of water and it will maintain your water at the precise temperature you choose. LED display, Bluetooth, timer, circulates the water for you, seems a very handy piece of kit for a brewer. The only problem being they are made only to use in water. I haven’t heard of any issue using them for wort, but it is something to be mindful of. Pictured is one of the more popular models, the Anova….
Do you have a large slow cooker at home?I havent really read up on his method but another possibility….
Feel free to comment is you’ve got another method for small mashes, if it works well I’d be happy to add it too my blog..
Until next time, happy brewing 🍺