Most of the process for making alcoholic and non-alcoholic beer is fairly similar. Both types of beer go through similar steps like making a mash and boiling the wort. Blending in the hops and fermentation happens in both of the processes. The main difference for most non-alcoholic beers is that the beer has to be heated. 

When beer is heated, the alcohol in the beer starts to evaporate. Unfortunately for beer drinkers, this heat can change the taste of the fermented beer. To prevent the taste from changing, some breweries use vacuum distilling. This process uses a vacuum to lower alcohol’s boiling point as much as possible. Instead of heating the beer to a hot temperature, the beer only reaches a fairly warm temperature. This technique helps to keep the flavors intact while reducing the alcohol content. 

In recent years, distillers and brewers have become more creative in how they remove the alcohol. One popular technique is to use reverse osmosis. This technique basically pushes the beer through the filter. The holes in the filter are small enough that only water, alcohol and a few volatile acids can actually go through the filter. Once this is done, the alcohol can be distilled from the alcohol and water mixture using standard distillation. 

Meanwhile, a syrup of sugar, ingredients and flavors still sits on the other side of the filter. Once the alcohol is distilled from the water, the remaining water and acids are returned to the syrup that sits on the opposing side of the filter. None of the main ingredients and flavors ever have to be heated in this process. Because of this, the resulting beer has a stronger, more natural flavor. This technique takes more equipment and labor hours, but it yields some of the best results. 

The beer process is not over quite yet. Now, the non-alcoholic beer looks and tastes like normal beer. The only problem is that it is completely flat. Normally, alcoholic beer becomes carbonated as it ferments within the bottle. Yeast metabolizes sugar within the beer to create more alcohol. As a byproduct, carbon dioxide is made. It is the carbon dioxide that causes beer to be carbonated.

Non-alcoholic beers are different. The entire goal of the process is to prevent fermentation and to limit yeast. Because of this, a non-alcohol beer will not ferment and create bubbles once it is bottled. At most breweries, the brewer will inject carbon dioxide into the bottle, keg or can. This technique is similar to what soda manufacturers do to create carbonated soda. 

There are some manufacturers who try to make their beer more authentic. They might use some starter yeast and extra sugar in the bottles so that the beer starts to ferment. This process might make carbonating the beer easier, but it also increases the alcohol levels. If this step is done incorrectly, it can also cause the bottles to explode.