Toasting Rye Malt

Toasting Rye Malt

Toasted rye tastes wonderful in beer. It is a typical ingredient in sahti farmhouse ale and an outstanding flavor booster for various dark beers. This kind medium-dark rye malt is rarely sold but with this guide you can easily toast your own at home.

I started toasting experiments with rye to mimic commercial Finnish dark rye malt Tuoppi Kaljamallas produced by Finnish malthouse Laihian mallas. Most contemporary Finnish sahtis get their rye flavor and reddish-brown color from this malt. As a Finn I can easily buy this malt but most of my readers cannot. Therefore, I started to test substitutes for this malt.

I found that home-toasted rye malt is not only a great substitute for Kaljamallas but also an outstanding addition to various kinds of beers. Over the years I have toasted barley, oats, and rye for my homebrews but rye is by far my favorite grain for toasting. This guide shows step by step how to make and use this kind of dark rye malt.

Tasting sahti brewed with home-toasted rye
My homebrewed sahti with home-toasted rye. Toasted rye malt gives a fantastic nutty and toasty taste of rye along with the typical reddish-brown color of sahti.

Other Resources

I’m certainly not the first suggesting toasting malt at home. I learned to toast malt by reading book Old British Beers and How to Make Them. John Palmer’s first edition of How to Brew contains good chapter on home-toasted malt. Brewer and beer writer Mike Karnowski has written excellent instructions for home-toasting, see his article How to Toast Specialty Malts and book Homebrew Beyond the Basics. I stumbled upon Karnowski’s work while writing this article and found many similarities in our thinking. Thank’s Mike for clarifying my thoughts!

If you want to learn more about sahti and rye, check my book Viking Age Brew: The Craft of Brewing Sahti Farmhouse Ale.

Why Bother Toasting Malt at Home?

Today we are spoiled with a wide range of excellent commercial malts. Yet, some medium-dark specialty malts can be difficult to buy. Toasted rye malt is one of them. Commercial amber and brown barley malts are available but when mimicking historical British beers you may want to toast the malts yourself.

Even if you could buy the needed toasted malt, I can think of several good reasons for toasting your own. When the malt is used soon after toasting, the toasty flavor is incredibly fresh. I like to have full control over the toast level and color too. Home-toasted malt adds a very personal touch to your beer.

Gradually home-toasted rye malt has become a signature flavor for some of my homebrews. Nevertheless, I’m still a big fan of commercial caramel and chocolate rye malts.

How to Toast Malt at Home

Malt can be toasted in various ways but I have had excellent results with the very simple procedure described below. The simplicity gives control and repeatability. I’ll comment on the variations later.

The idea is to toast pale malt into darker malt at 175°C (350°F). You can control the toast level with time. The kitchen oven makes enough toasted rye for a few tens of liters of beer. If you are brewing hundreds or thousands of liters, you need a bigger oven.

This toasting method work for all grains but the toasting times may differ. The toasting times below are for rye malt. In my experience, barley requires slightly more time than rye.

Depending on the toast time I divide malt into light, medium and dark toast levels:

Light toast: 15 minutes gives a slightly toasty, nutty, and biscuity flavor. The interior grain color should be light buff.

Medium toast: After 30–45 minutes the flavor is firmly toasty, nutty, and raisiny. North Americans describe this flavor as grape nuts. The color inside the grain should be from brown paper to chestnut brown. My no-fan kitchen oven produces the best medium toast rye malt at 45 minutes.

Dark toast: At 60 minutes you start to get coffee and cocoa-like flavors. The roasty flavors are still delicate compared to chocolate or black malts. The result is somewhat similar to commercial pale chocolate malt with pronounced milk chocolate flavor.

These toasting times are rough estimates based on my experiments with a no-fan oven. With an oven fan, you may get the same results in a shorter time. Ovens are different and oven thermostats are terribly inaccurate. You need to monitor the toasting process, as advised below.

Home-toasted rye malt in baking sheet
0.3 kg toasted rye malt for a small test batch. With my kitchen oven 0.7 kg is the maximum amount for one baking sheet. That’s enough for 20–30 liters of beer.

The Malt Toasting Procedure

Preheat the oven to 175°C (350°F). Line a baking sheet with aluminum foil. This way you avoid getting grease into your grain and removing the grain is easier. Spread the malt onto the sheet. For optimal results, keep the malt layer thin, not more than a depth of 15 mm (around 2/3 inch). If you need more toasted malts, use either two baking sheets or toast several times.

Put the baking sheet into the oven. If your oven has a fan, use it. Start monitoring the progress five minutes or so before the target time. The outer grain remains paler than the kernel. The grains will be unevenly toasted and you need the estimate the toasting level on average. Hence you need to take out a few grains for monitoring: slice the kernels in half, check the inside color and taste the grains.

For the lightest toast grade, the kernel should be light beige in color. The taste should be biscuity and bready. For the medium grade, the taste should be nutty and toasty but not very coffee-like. The color inside the grain should vary from brown paper bag to chestnut brown. Grains should not be charred at all. In the darkest grade, some kernels will be very dark brown and coffee flavor becomes apparent.

Once you have reached desired toasting grade, take the grains out from the oven and let them cool.

Home-toasted rye malt
Rye malt on the left has been toasted for 45 minutes. The grain interior color varies from brown paper to chestnut brown. The grains on the right have been toasted for 60 minutes. Some kernels are still paper-brown or chestnut-colored but some grains are very dark brown. Judging by color alone is tricky. Taste the grains as well. The darkest grains on the right add a coffee flavor that you want to avoid in the 45-minute medium toast.

Toasting Rye for Sahti

Here are some extra tips for sahti brewers.

Today majority of Finnish sahtis contain a 5–10 % share of Finnish dark rye malt known as Tuoppi Kaljamallas. This commercial malt provides nutty, bready, and raisiny flavors of rye along with reddish-brown color, smooth mouthfeel.

Finnish toasted rye malt, Tuoppi Kaljamallas
Tuoppi Kaljamallas is a commercial malt produced by Finnish malthouse Laihian mallas. It is sold pre-crushed in Finnish grocery stores. As far as I know, it is not exported but home-toasted rye is a great substitute.

I don’t know how Kaljamallas is produced but tasting and looking at the malt reveals a lot. The bran of Kaljamallas has been removed and it looks fairly uniformly dark brown, almost like a chocolate malt. Yet, the malt doesn’t add chocolate or coffee flavors. Neither the malt has caramel crystals or flavors. Therefore, I have classified Kaljamallas as toasted malt. The color unit of Kaljamallas is 180 EBC (around 60–70 Lovibond).

Home-toasted rye malt mimics Finnish Kaljamallas well. In my brewing tests, the beer color has been very similar. The flavor difference is recognizable but home-toasted rye doesn’t throw the flavor off from what Finns think as good and traditional sahti. Home-toasted rye tastes slightly more biscuity and toasty. I like the extra kick that home-toasting brings.

I think that removing the bran gives Kaljamallas a soft toasted flavor yet with a surprisingly dark malt color. If I toast rye to the dark brown hue of Kaljamallas, I get chocolate and coffee flavors that most sahti drinkers would find inappropriate in a traditional sahti. Therefore, medium toast rye is the best approximation for Kaljamallas.

NOTE: before these toasting experiments I recommended substituting Kaljamallas with caramel rye malt. It is not a bad substitute but medium-toast rye makes by far better and more authentic sahti.

How to Brew With Home-Toasted Malt

Many sources recommend letting the toasted malt rest for at least two weeks before use. This rest is said to mellow the harsher aromatics. Commercial maltsters let the malt rest but I don’t see a need to wait. On the contrary, I like very fresh toasted flavors. Usually, I toast malts a day or two before brewing.

The malt made with the above procedure has a strong taste and best used in small quantities. I recommend using up to 10 % of the total malt amount, but that of course depends on the toasting level and your preferences. For sahti, I would use 5-8 %, and for porters and stouts around 8 %. 1-5 % adds a delicate touch, suitable for all kinds of malt-forward beers. With the toasting procedure above the malt loses its enzymes.

A glass of rye porter on a lakeside
I like soft and mellow porters with plenty of toasty and nutty flavors. Toasted rye malt is perfect for that.

Toasting Procedure Variations

The procedure above works with various grains, both malted and unmalted. You can also toast flakes or cracked grains. I usually toast rye malt because I like the result and the appetite for rye is in my genes. If you have a favorite local grain I recommend toasting that.

Toasting at 175°C works extremely well but varying the toasting temperature can be an interesting tool. For example, if you want to make diastatic toasted malt similar to historical amber or brown malts you need lower temperatures. Making chocolate or black malt would require higher temperatures but a kitchen oven is not optimal for making roasted malts: dry grain at high temperatures catches fire easily. Commercial maltsters avoid this problem using revolving roasting drums.

You can also make caramel malt by heating wet grains. Normally caramel malts are made by heating whole wet sprouted grains but in my opinion, there’s a more interesting method for homebrewers: bake your mash in the oven similar to Lithuanian farmhouse ale Keptinis. This is an easy way to get highly complex and outstanding caramel flavors. I’m writing a Brewing Nordic story about this kind of mash baking and I’ll add a link here once published.

Recipes with Toasted Rye

If you want to brew sahti, look no further than my Sahti Recipe and Farmhouse Brewing Tips. It is probably the most popular sahti recipe on the internet and toasted rye malt is one of the key ingredients.

I’m currently writing a guide about brewing with rye. The guide will contain recipes for rye porter and rye sahti, both featuring home-toasted rye.

6 thoughts on “Toasting Rye Malt

  • September 5, 2021 at 9:35 pm

    As a rye lover, congratulations for your very interesting article.
    I think rye malt in all its variations is an excelent ally to give character to our beers.
    My last sahti contains a gentle 25% rye malt, of which only 2.8% cara-rye. (150-200 EBC)
    I would have liked reach for at least 5 to 7% in my total grain bill but I didn’t have enough of this type of rye malt.
    However, I noticed that it was intersting to try cara-rye before transforming your malt yourself.
    Never mind, for the next few batches, I’ll try your method with basic rye malt to improve my recipes.
    Your feedback on using a certain freshness right after toasting is also intersting. Kept in mind to me.
    A while ago, I had toasted oat flakes in a kitchen oven too for a winter brew with good results in terms of taste and color. I just have to do it again in a larger scale now. 🙂
    Treating his grains to brew them yourself, as smoking malt as I like to do for example, seems good to me cause this way you can get a particular drink that is unique to you. Like using local ingredients too.
    All of your tips here inspire me for future brews again and again. Thank you!
    And I’m excited to read your guide to brewing with rye.


    • September 7, 2021 at 5:43 am

      Thanks, Guillaume! Cara-rye is excellent malt and I use it fairly often. Raw ales highlight the candy-like sweetness of caramel malt. In a sweet and strong ale with little bitterness that candy flavor can taste overwhelming. For this reason, I prefer toasted rye in sahti.

    • September 14, 2021 at 4:23 pm

      Thanks Johann! I’m sure you’ll like the next story “Brewing with Rye”.

  • January 11, 2022 at 4:12 pm

    Hallo, Thanks for interesting and valuable information. I would like to ask about toasting raw rye against malted. Are there any differences between them if rye malt with this procedure losses its enzymes?

    • January 13, 2022 at 5:52 am

      I haven’t tested this. I suspect that there is a small flavor difference but I’m sure raw rye can be toasted as well. In the old days some sahti brewers sprinkled rye flour (unmalted) on a hot stone where it burned. Then they added the stone to the mash to get darker beer color.


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