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Kyle Brown

Owner of Clawhammer Supply

Brewing 101 > Extract Brewing > Partial Mash Brewing > All Grain Brewing

When the beer turns out well, brewing is a rewarding process. But what happens when it doesn't? And when does that happen? One issue that can send a brew day sideways is incorrect mash temperature. Mashing is the process where starch is turned into sugar. And without sugar, there is nothing for yeast to eat and turn into alcohol.

Thankfully there are multiple methods for brewing beer, each appealing to a different skill level and brewing preferences. One such method is partial mash brewing. This method would make the above mentioned problem less of an issue because only part of the sugar in partial mash recipes comes from the beer mash.

Extract vs. Partial Mash vs. All-Grain Brewing

The three most common brewing techniques, ranked by complexity, are Extract Brewing, Partial Mash Brewing, and All-Grain Brewing. Each method offers its unique benefits and challenges, with extract brewing being the most straightforward, partial mash brewing introducing a little more complexity, and all-grain brewing standing as the most advanced.

The partial mash brewing technique strikes a balance between the simplicity of the extract brewing process, which is very simple and doesn't leave a lot of room for creativity, and all-grain brewing, which can be a bit of rabbit hole in terms of options and complexity. Partial mash brewing is a perfect stepping stone between beginning and advanced brewing methods, building upon the fundamentals while not introducing an overwhelming amount of change.

What is Partial Mash Brewing?

During the beer-making process yeast eat sugar and create alcohol. It's perhaps the most important part of the process. The distinguishing factor between the three brewing methods—extract, partial mash, and all-grain—lies in how the sugar is introduced into the beer recipe. Extract brewing relies on pre-made malt extract as the sugar source for fermentation. All-grain typically involves on creating all of the sugar for fermentation by mashing malted grain. Partial mash brewing is a beer making method that utilizes a combination of malt extract (dry or liquid) and and a small mash of malted grains to supply the sugar needed for fermentation.

Why Chose Partial Mash Brewing?

There many more grain types than there are liquid and dry malt extract options. For example, a well stocked local homebrew store will often stock dozens, and even hundreds of types of grain. But they'll only typically carry less than a dozen types of malt extract. This means that brewers are limited in what they can make when only relying on malt extract.

Advantages of Partial Mash Brewing

Transitioning from extract brewing to the partial mash brewing method has many  advantages. Though, perhaps the most significant advantage is that it allows new brewers to advance their skills while maintaining a safety net while opening more opportunities in terms of beer styles and recipe customization.

As mentioned above, extract brewing relies entirely on liquid malt extract sugar and all-grain relies entirely on the mash for sugar creation. The risk of the latter method is that overshooting mash temperature could result in denaturing of amylase enzymes, which would prevent the production of sugars required for fermentation. In this scenario, the beer would be completely ruined.

Partial mash brewing, however, provides a safety net in the sense that even if mashing doesn't go entirely as planned, the beer will still be salvageable. The majority of the sugar in partial mash recipes still come from malt extract. This allows new brewers to try their hand at mashing with a built-in backup plan.

Other advantages of partial mash brewing include the following:

1. Next Brewing Step

   Partial mash brewing provides a less intimidating entry point for those transitioning from extract brewing, as it still involves the use of malt extract, a familiar ingredient.

2. More Beer Style Options

   This method allows brewers more flexibility to experiment with grain types and ratios than extract brewing, contributing to a broader range of flavors, aromas, and colors in the final product.

3. Customized Beer Characteristics

   Partial mash gives brewers more control over the final product than extract brewing, as they can adjust the mash process (like temperature and duration) to influence the beer's taste and mouthfeel.

4. A Cost-effective Brewery

   Partial mash brewing can be more cost-effective than all-grain brewing because it requires less equipment. Don't have $1000 to drop on an all-grain brewing system? No problem, partial mash brewing equipment is typically less expensive. It can also be made using standard kitchen equipment and an entry level fermenter.

5. Space Efficient

   Partial mash brewing doesn't require as much space as all-grain brewing due to the fact that it requires less equipment, making it an excellent option for brewers with limited storage space.

6. Learning

   This method offers a great opportunity to learn about the mashing process before moving on to all-grain brewing, enabling brewers to gain experience and confidence.

How to Make Partial Mash Beer

A small amount of un-malted grain is often added to extract beer recipes. Because the grain is unmalted, there are no enzymes present to convert starch into sugar. This means that extract grain additions only contribute to flavor, color, and aroma. 

The amount of grain added to partial mash beer is generally larger than the additions used in extract brews. Also, in partial mash brewing, malted grain is added, which contains starch conversion enzymes. The malted grain is steeped at mash temperature, prompting enzymes to convert starch into sugar which means that this grain addition will increase the total sugar in the recipe will also boost the final alcohol by volume, in addition to contributing to aroma, flavor and color.

Here's a step by step process for making partial mash beer:

1. Heat water to mash temperature (somewhere between 140 and 160F)
2. Pour malted grain to a nylon bag
3. Insert the bag of grain into the water and allow it to sit, or “mash,” for 60 minutes
4. Remove grains
5. Heat to a boil
6. Turn off heat
7. Dissolve the liquid (or dried) extract sugar
8. Turn on heat
9. Boil and add hops
10. Cool to room temperature
11. Aerate and add yeast
12. Package and carbonate

Partial Mash Pro Tips

The most important thing to focus on when moving on to partial mash brewing from extract brewing is the steeping (i.e. mash) temperature. Saccharification enzymes are most active between the temperatures of 140 Fahrenheit to 160 Fahrenheit. The enzymes also “denature,” meaning they are destroyed, at temperatures above 170F. So, do your best to stay within this range.

Beer Making Guide

Brewing 101 - Extract Brewing - Partial Mash Brewing - All Grain Brewing