Oat milk is delicious, rich in beta-glucan, and much kinder on the environment than cow’s milk and other popular plant milks. I’ve been blending my own for a while now and when I open the fridge, the antique bottle I dug up in the backyard (very clean, don’t panic) stands in place of a carton that would’ve been thrown out. All that sounds dandy, but I was never completely satisfied with how my oat milk turned out. For one, it’s never been as sweet or as creamy as the commercial stuff. But you know what’s worse? Unprocessed oat milk is deathly afraid of coffee and tea. Blend it for too long? Slime. Use it in your hot drink? Slime. Over handle it in any way? You guessed it: slime!
I’ve been on a search the last couple of months for a way to close the gap between home-made and store-bought, and for a while I got lost trawling through reddit posts, diving deep into beer-brewing forums, reading oat-milk patents and scientific papers, and doing lots and lots of experiments. But there is light at the end of the tunnel, and it turns out there is a solution for better oat milk, and it’s not chilling your oats, blending them gently, or using a finer strainer.
The hero is malted barley
If oats are my damsel in distress, waiting for someone to save them from a slimy end in the horror of a hot drink, then the hero of my story is malted barley. Actually, barley is more of a super-hero given the amazing transformation it can perform. It has the power to turn gloopy, starchy oats into full-bodied milk, with just a hint of natural sweetness. And it does all this with the help of an enzyme called amylase — an enzyme which your beer-brewing friends are already well acquainted with.
A bit of background. When a grain hits water, an enzyme known as amylase — whose job it is to break starch down into sugar — is released. Malting takes advantage of the amylase released by young seeds by first activating and then dehydrating them. Malted barley just so happens to be one of the richest sources of both alpha and beta amylase.
If you’re feeling adventurous, there are guides online that walk you through malting your own barley. Given we now have a dehydrator, I’m keen to try the process myself. But if you’d rather skip to the fun part, then you can find barley at certain grocery stores, and from brewing suppliers. Just make sure that it is advertised as having diastatic power, which is measure of how well it can convert starch into sugar. That ability is the key to breaking down oat slime and enhancing the drink’s natural sweetness.
Start your day with a pat on the back
A great thing about making your own oat milk is that the raw ingredients are obscenely cheap. On average, they’re much more affordable than other plant milk ingredients. Here’s an idea of the relative cost: at my local organic bulk foods supplier, the raw ingredients to make 1 litre of barley and oat milk are around 30 cents, for soy they are about 75 cents, and almond milk will set you back a whopping $5. That means almond milk is more than 15 times as costly. Nuts are a very expensive and inefficient way to make milk.
Not only that, but the by-product of this milk is an inoffensive blend of finely milled oats and barley and the quantity is very manageable. Don’t throw it away! It makes a great addition to sourdough, pancakes, smoothies and even mixed in with some more oats to make porridge.
Oats and barley are also great for the environment. A study by Oxford University in 2018 found that oat milk requires less land and water to produce, and its production generates much less greenhouse gas than dairy milk. It requires much less water to produce than almond milk.
Breakfast should be easy
So what about the recipe? With a bit of planning ahead, you can enjoy home-made oat milk without the slime in just over half an hour. And most of that time is set and forget.
There are a few recipes floating around the internet that use amylase, but they’re time-consuming and not achievable for the average person. They usually demand a lot of attention to make sure that amylase works its magic. As much as I love experimenting in the kitchen, this is something I make at least once a week, so it needs to be dead simple.
Luckily, I’ve got a solution for that too. I’ve figured out the key ratios, times and temperatures required to make delicious oat milk in your own kitchen, even when you’re still waiting for your brain to power on.
Dissolving oat milk’s slimy reputation
I had a bit of an aha-moment during my experimentation, when I realised that beta amylase is doing most of the heavy lifting, and so the only temperature that matters for converting slime into sweetness is between 60 and 65°C (140 and 149°F). Even better, by avoiding the beta-glucanase temperature range, we can also keep the heart-healthy beta-glucan fibre intact.
As long as we hit the high end of that range and hold the temperature between half an hour and an hour, we’re looking good. Actually, I recommend aiming a little higher than the upper temperature, at around 67°C (152°F), to account for cooling as you prepare your ingredients.
All we need is a way to keep our concoction within the appropriate temperature range to fully activate our added enzymes without denaturing them. Most recipes call for complicated equipment to do this, like a dehydrator, a slow cooker, or a sous vide machine to maintain the right temperature, but all you really need is a vacuum flask. Yep, one of those things you keep your drinks warm or cool.
Guess what? You don’t even need a thermometer. If you stash some tap water in the fridge overnight, you can get the right temperature by mixing 2 parts boiling water to 1 part refrigerated water. For 1 litre of water, that’s about 320ml fridge water and 680ml boiling. Of course, you can use your preferred way of getting water to 67°C (153°F), but I like the simplicity of mixing it up. Works every time.
To grind or not to grind
Even better, if you mill your oat and barley in bulk and keep them fresh in a ziplock bag in the fridge or freezer, then you have powdered oat milk on hand. An occasional shake of your vacuum flask is all that’s required to combine your drink.
If you want to make your life even easier, you can opt to buy oat flour and malted barley powder and save yourself time milling. Just remember that barley’s super-power comes from its enzymes and it will retain its strength for longer as a whole grain rather than a powder.
Once you’re done, you just have to strain the pulp from the milk and let it cool in a glass bottle or jar. If you want to stop the enzymes from doing any further work and extend the shelf life of your drink, you can boil the drink now. The great thing is, the oats have already avoided their gloopy end. They can hit that heat and live to tell the tale.
Malted barley and oat milkServes 8 Makes 1 litre Prep Time: 12 hours Cook Time: 1 hour 38 minutes Total Time: 13 hours 38 minutes
13 hours 38 minutes
- Vacuum flask
- 80 grams oat flour or processed rolled oats
- 40 grams barley malt
- 1 litre water at 67°C (153°F) 320ml refrigerated + 680ml boiling
12 hoursChill water If you don't have a temperature-controlled kettle or a food thermometer, then place half a litre of water into the fridge and leave it to chill for at least 12 hours.
5 minutesBring water to temperature Combine 320ml of refrigerated water with 680ml of boiled water. Alternatively, heat water to 67°C (153°F) using a temperature-controlled kettle or a pot and a thermometer.
1 minuteCombine all ingredients Vigorously stir the oat flour and malted barley into the heated water.
1 minutePour into a vacuum flask Pour the mixture into a vacuum flask and seal it.
1 hourLet the enzymes work Set a timer for 30 minutes to 1 hour, and let the drink develop until the timer goes off. The longer you leave the drink, the sweeter it will get, so play around with shorter or longer times until you get a result that you like.
1 minuteStrain out the milk Once the time has elapsed, open the vacuum flask and strain the liquid through a fine-meshed sieve into a glass bottle or jar for storage.
30 minutesLet it cool Wait for the drink to cool to room temperature before drinking it. Store it in the fridge and enjoy it for up to 5 days.