Partial mash brewing is an interesting approach to brewing, and is essentially a middle step between all grain brewing and extract brewing. This makes it an important step for new brewers who want to experience something beyond extract brewing, but are not ready for the full commitment of full grain brewing. Like extract brewing, partial mash brewing requires fewer steps also makes use of less equipment than if you were to upgrade to an all grain kit.
In terms of processes, partial mash brewing has more similarities to extract brewing than it does to all grain brewing. The brewing uses some fermentable sugars from extract, while the rest of them come from mashed grain. The process of mashing for partial mash brewing involves crushing the grain and allowing it to seep for around an hour. After this, the remaining spent grains are separated from the wort, and the boil is then continued as you would with an extract kit.
In terms of equipment, partial mash brewing largely makes use of the equipment used for extract brewing. The only significant extra pieces of equipment needed are an extra cook pot, a grain bag or a strainer, and a floating thermometer. All of these pieces of equipment can be obtained easily and at relatively low cost. Any person who is going from all grain brewing to partial mash brewing will find that they already have all the resources that they need.
Why would you want to downgrade? Using a partial mash can allow you to experiment and refine certain techniques with fewer variables that may mess up your results. A can of pale ale extract is always going to be the same as long as you buy the same brand from the same company. But making the same pale ale base beer by mashing your own grain will probably yield different results each time.
If you want to experiment with hops, yeast, or other additives like chocolate, coconut, vanilla, chiles, etc and want to have stable constants for precise comparison, this could be a good way to do it.
The process differences between partial mash brewing and extract brewing are also relatively simple and just involve the addition of one extra stage, which is mashing. The mashing process is not challenging, making partial mash brewing easy for extract brewers to pick up. If you haven't got 6 hours, or it's just too damn cold outside, small batch partials can still make awesome beer, and NO, it's not “cheating”
Why Partial Mash?
Aside from the increased simplicity and lower time consumption, the other major advantage of partial mash is that it increases the amount of control the brewer has on their final product. The fact that partial mash brewing involves the use of some mashed grain and some extract means that there are a lot of options. This allows for more experimentation when compared to extract brewing, and gives the brewer the chance to develop their own personal style.
Another thing to consider is that partial mash allows brewers this freedom without the level of commitment required in full grain brewing. This means that the brewer can easily go back to extract brewing and they won't have lost much in the way of investment.
Which one are you?
You might fit one of two categories at this point: The first, and most common, is when a brewer has been doing extract brewing and is looking for something a bit more challenging or a bit more interesting. For this type of brewer, partial mash lets them try out some of the elements of all grain brewing, while still retaining some of the simple aspects of extract brewing. What type of beer are you looking to make? Leave a comment and let us know!
The other reason why a person moves to partial mash brewing, is when the processes and the time involved in all grain brewing become too significant. For example, an experienced brewer might find a new job with more hours, but not want to give up on their brewing. Is this you? Tell us what you think of partial mashes, and if you still prefer all grain!
Photo by by malcolmduchamp