What is double mashing, and why do we need it?

In principle, double mashing means portioning the amount of malt in two or more stages. This way, you avoid spills and overflowing malt pipes by performing the mash in several rounds.

Advantages and disadvantages of double mashing

Have you tried imperial stout, Belgian quadruple, barley wine, or other strong beer types that require large quantities of malt? Then you have probably experienced a problematic brew day with an overflowing malt pipe, heavy lifting, and a lot of mess.

Many brewing systems have tall and narrow designs. This can present challenges, and it can be especially difficult to extract as much sugar as you want. Sometimes, the malt base is simply too large for your particular brewing system.

Of course, there are quick and easy "shortcuts" to bypass large quantities of malt, and often the result can be good. However, if you want to do it properly, and without compromise, double mashing is a good solution that gives you full control over the beer's content.

Double mashing makes the brew day a little longer, but it can make the work less strenuous. And most brewing enthusiasts will agree that the result is worth the extra effort.

Keep it simple – divide the mash in two

The simple method is to divide the mash directly in two. To explain it simply, let's take an example where we are going to mash with 12 kg of malt in a brewing system that has a maximum capacity of 8 kg.

1. Instead of stuffing your brewing system/kettle completely full, measure out the water quantity for 6 kg of malt.
2. Mash in 6 kg of malt into this, and let it stand for the usual mash time. You don't need to mash out here, as you will have the same temperature for the second round.
3. After the mash time, lift the malt pipe and sparge with the same number of liters of water as the number of kilograms of malt. In this case, you should sparge with 6 liters of water. After sparging, you should end up with approximately the same amount of water as you started with before mashing.
4. Empty and clean the malt pipe so that it is ready for use again.
5. Mash in the second half of the malt into the wort you made in the first round, and let it stand for the usual mash time again. This time, you can mash out if you wish.
6. Sparge as usual. The rest of the brewing process should proceed as normal from here.

In most cases, you can expect that you will not get as good an extraction as with normal mashing with a regular amount of malt. Nevertheless, it will be significantly better than with an overflowing malt pipe, and at the same time, you will have a simpler brew day. Since double mashing gives you more space, you can compensate by using a little extra base malt.

If you are brewing a beer with a lot of specialty malt, we recommend using all the specialty malt in the second mash round. Note also that the wort here becomes very strong and thick, so in the second round, we strongly recommend adding a handful of rice hulls to prevent it from becoming too dense and difficult to sparge (stuck mash).

Double mashing with the "No sparge" method

The "No sparge" method is an alternative way to double mash. This method takes a good deal of time, but the yield is also correspondingly better than with traditional double mashing. "No sparge" is excellent for beer styles that can be boiled for a very long time. For example, bock, barley wine, and beer types that benefit from some caramelization.

Similar to traditional double mashing, the malt should be divided in two. We use an example in the procedure:

1. Calculate the water amount for the first mash round so that you end up with just under half of the maximum volume in the kettle. For example, if you have a kettle that is completely full at 46 liters, you can calculate that you should have 20-22 liters remaining after the first mash. Do not calculate sparge water; everything should go into the mash.
2. Mash the first round as usual, but do not sparge the malt. Hence the name: No-sparge.
3. Cool down the first round of wort, and transfer it to another container. For example, a fermenter or another kettle. If you are brewing on HERMS, this can be transferred directly to the kettle.
4. Repeat the same process with new water and the second half of the malt.
5. Once both mash rounds are complete, combine them in the kettle and boil until you have achieved the desired amount of wort. Here you can really concentrate the wort as much as you want, and also get a great caramelization. Allow plenty of time, as it can easily boil for several hours.
6. If you wish, and still have the motivation to brew after such a long boiling time, it is also possible to sparge the spent grains separately. Then you can get an extra small batch of lighter beer from this (second runnings).

Simple shortcuts to strong beer

For some, time does not allow for mashing and boiling for hours in a busy everyday life. That should not prevent you from brewing strong beers. There are, of course, quick and easy "shortcuts" to strong beer.

Dry Malt Extract (DME) and Liquid Malt Extract (LME)

Using dry malt extract and liquid malt extract is absolutely the easiest method, and it does not extend the brew day either. Feel free to replace parts of the base malt with DME or LME to increase the OG (the original gravity of the beer). If you use software to build your recipe, DME and LME will often be listed as separate ingredients you can add, and also calculate how much you increase the OG.

You can also use dextrose or table sugar, but it is important to remember that pure sugar types will often ferment out completely. This means that you can brew a strong and powerful beer, but it can often feel thin or boozy as sugar only adds alcohol, but no body and mouthfeel to your beer.

Half batch and "no sparge"

If you want to brew strong beers, but don't want to double mash or add DME or extract, you can compensate with half the amount. That is, you brew half as much as you usually would. Then you have plenty of space for the malt, and get a strong wort, but compensate with a smaller quantity.

If large quantities of malt are still involved, "no sparge" can be an alternative. This means that you do not sparge the malt after mashing, but instead add all the water to the mash. However, one should consider that mashing efficiency can decrease with "no sparge," as you do not sparge out all the sugar after mashing.