How to make Oat Milk at home (DIY): cheap, delicious and not “slimy”

First I have to correct the title: legally I should not call it “How to make Oat Milk at home“, but “How to make Oat Drink at home“.

As I was explaining it in “Homemade Soy Milk” the reason why we buy oat milk, is not because we confuse it with cow’s milk. But the rule are rules, we should obey them. As it is for soy drink, also oat drink is bought for many reasons, mine for example is that of wanting to be more ethical in my food choices; it is appreciated not only by vegans but also by those who are lactose intolerant: these latter, although omnivores, can not take animal products containing lactose.
It is not as rich in proteins, iron and calcium as soybean, but it is mostly preferred for its mild and pleasant taste. Moreover it is a good source of mineral salts (phosphor, magnesium, zinc), of thiamine (Vitamin B1), and of fibers (both insoluble and soluble), in particular beta-glucans, which are responsible for giving oats the medal of being “a food capable of reducing both cholesterol⁽¹⁾ and glycemia⁽²⁾“.
Therefore, it would not be wrong to say that consuming oats is good for health.
Besides the health benefits, knowing how to make oat milk brings with it another advantage; in my opinion of some importance: affordability. Those who are already users of oat flakes, will know well that even if they are organic, their price is more than budget friendly: the price of organic oat flakes hardly ever exceeds 3,00 euro/per half a kilo. This pleasant characteristic is dramatically increased when the flakes are transformed into milk, sometimes costing even more than 3.00 euros per liter.
As you will see in a moment, to obtain a liter of homemade oat milk you need to use only 100 grams of flakes; the rest is water, so the cost never exceeds 70 cents per liter.

Honestly, I have to warn you that although the processing steps are pretty easy, the result can be very different (negatively unfortunately) from the industrial one. However if you are here, I am sure that organoleptic preferences are not at the top of your scale of values; rather sustainability, health and affordability.

Some brands contain additives such as calcium carbonate (labeled as E170, it is used as an acidity corrector, anti-caking agent, colorant, and believed to be harmless to human health); calcium triphosphate (labeled as E341 (iii), it is used as an anti-caking agent, and in high doses may impair calcium assimilation) or gellan gum (labeled as E418, it is used to keep proteins in suspension/stabilizing agent, and in high doses could cause flatulence or diarrhea); which allow to obtain a product perfectly dense, fluid and immune to heat (in the sense that it does not coagulate even if it is heated, as unfortunately happens with the homemade drink).
And there is the matter of “sliminess“.
 

Why does homemade oat milk become slimy?

This phenomenon is caused by the natural gelatinization of the starch present in the composition of oats. In order to prepare the beverage at home, first the oats are soaked; in this way the amylose which constitutes the starch (together with amylopectin), begins to absorb water; when we then use the blender in order to make the oat flakes become a puree, with the increase of temperature caused by the heating of the blades (which rotate for 1-2 or more minutes), the amylose gelatinizes and assumes the new characteristic, definable slimy and stringy. That is why in the industrial production of starchy vegetable beverages such as oats and rice, in order to avoid this phenomenon, starch must be converted into sugar by means of an enzymatic reaction, with the addition of amylase: which allows the scission of complex sugars (amylose), into simple sugars (glucose). This is the reason why bought oat drink is sweeter even though it does not contain added sugars, whereas home made oat drink needs to be sweetened in order to taste it as a drink. The reason why the enzymes in question are not mentioned in the label is because they are a production aid, there is no obligation to declare them in the label.
Lastly, the vegetable beverage is heat treated (UHT) in order to last for a long time on the shelves; in this way enzymes also degrade and “disappear from the scene”.
All of the above gives us an excellent product from every point of view, but at a higher price.
We can respect some tricks (which will be explained later) to improve the situation; however if you do not use enymes and additives, the result may never compete with the industrial one. However, I am certain that who wants to learn how to make oat milk at home, knowing the above mentioned characteristics, will avoid uses that are not appropriate for a product containing only oats and water: such as drinking it hot; or not being frightened when in the morning we find a product with two well separated layers, of water and oats (just shake it a little and it becomes one again). 

Ingredients (for approx 0,8-1 Lt of oat milk)

100 grams of old fashioned / rolled oats
0.8-1 Lt of very cold / icy water

For flavoring

A tablespoon of cinnamon powder, or 2 tablespoons of cocoa or carob flour, or a vanilla pod (optional)
A pinch of salt (optional, but greatly enhances flavor)
Natural sweetener to taste (optional, you can use maple syrup or grape molasses, or a few tablespoons of honey or brown sugar or rice or barley malt etc.)
 

Directions

• Place oatmeal in a colander and rinse briefly under running water to remove impurities, then transfer to a container with ice water (no more than 200-300 ml). Using ice cold water is recommended to reduce the “slimy” effect!
  Let them soak for at least 30 minutes at room temperature; I usually leave them for 2 h, so as to eliminate some of the water-soluble anti-nutrients transferred in the soaking water (if you fear the slimy effect, reduce the soaking to max. 30 min). Drain the flakes using a colander.

Important Tip for How to Make Oat Milk not “SLIMY”

I suggest that you do not use fine oat flakes, nor instant oat flakes, nor oat flour, but rolled oat flakes (also called old fashioned), if you do not want a final result that is a bit “slimy“; that is what happens to fine oat flakes after soaking for just 30 minutes. Steel-cut oats, likewise, are not an ideal choice, as they are too coarse to create a drink that should be silky

• When turn the flakes into a smooth puree with a blender, adding just 200 ml of ice cold water. If you want to flavor or sweeten the homemade oat milk, you can do it now; or you can add your favorite flavors right at the moment of serving, it makes no difference. But here’s a very useful tip on using the blender: don’t use it more than half a minute, otherwise as I explained before, you will notice that your drink will look a bit slimy; you should also know that if you don’t have a powerful blender, unfortunately 30 seconds will not be enough.

• Next, run the liquid through a muslin or strainer or almond milk bag or clean dishcloth to separate the oat drink from its pulp, also known as okara. Don’t throw it away, you could use it to enrich your meatballs, cakes, oatmeal, etc.

• To drain the precious liquid well you must use your hands and “milk” the fabric, in the case of the bag; or a utensil such as a spoon, to gently push, in the case of the strainer.

• If needed, you can re-strain the liquid obtained, to make it more silky. Gradually add the remaining part of the ice water (0.6-0.8 l), you decide the final density.

• Now the homemade oat milk is ready to be transferred to the fridge, or to be enjoyed immediately.

• Since now you know how to make oat milk at home, you have no excuse!
   

Storage

Homemade oat milk, can ‘maintain’ its freshness in the refrigerator for up to 5 days in an airtight container.
Enjoy your oat milk and good revolution to all

Bibliography
1) Anne Whitehead, Eleanor J Beck, Susan Tosh, Thomas MS Wolever, Cholesterol-lowering effects of oat β-glucan: a meta-analysis of randomized controlled trials, The American Journal of Clinical Nutrition, Volume 100, Issue 6, December 2014, Pages 1413–1421, https://doi.org/10.3945/ajcn.114.086108
2) Chen J, Raymond K. Beta-glucans in the treatment of diabetes and associated cardiovascular risks. Vasc Health Risk Manag. 2008;4(6):1265-1272. doi:10.2147/vhrm.s3803

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