Unsweetened almond milk is mildly acidic, with a measured pH around 6.5, just below the neutral mark of 7.0. That puts it close to neutral and well above the acidity of fruit juices or sodas. But the question most people are really asking when they search this is whether almond milk is “acid-forming” or “alkaline-forming” in the body, which is a different question entirely from what a pH meter reads in your glass. The two answers diverge in ways that matter, and the wellness claims built on top of both are worth scrutinizing.
What a pH Meter Actually Reads
When researchers measure almond milk straight out of the carton, the numbers land in a fairly narrow range depending on what has been added to it. In an in vitro study that tested several milk types, unsweetened almond milk came in at a pH of about 6.48, while sucrose-sweetened almond milk dropped to roughly 4.56, the lowest pH of any milk tested, including cow’s milk and soy milk.1PubMed Central. Analysis of the Cariogenic Potential of Various Almond Milk Beverages using a Streptococcus mutans Biofilm Model in vitro That is a significant gap. A pH of 6.5 is barely acidic, comparable to most tap water. A pH of 4.5 is in the same neighborhood as tomato juice.
A separate comparison of ultra-high-temperature processed milks and their plant-based counterparts found that almond milk had the highest pH value among the nondairy beverages tested, ranking above soy, oat, rice, and coconut drinks, and even above UHT cow’s milk.2PubMed. A comparison of the quality of ultra-high-temperature milk and its plant-based analogs So if you are drinking a plain, unsweetened almond milk, you are drinking something that is essentially near-neutral. The acidity story changes dramatically, though, once sugar, flavorings, or acids used as preservatives enter the picture.
Why Sweetened and Flavored Versions Are So Much More Acidic
The nearly two-full-point drop in pH between unsweetened and sweetened almond milk is not because sugar itself is acidic. Sugar is pH-neutral in solution. The difference comes from what else gets added alongside the sugar. Flavored almond milks often include citric acid, ascorbic acid, or other acidulants for taste balance and shelf stability. Vanilla-flavored versions, chocolate versions, and “original” sweetened versions tend to carry these additives, and they push the pH down substantially.
This matters for your teeth more than for anything happening deeper in your body. Dental enamel begins to demineralize at a pH below about 5.5. A sweetened almond milk sitting at 4.5 is well within that erosive range, especially if you sip it slowly throughout the day. The same study that measured almond milk pH also looked at biofilm formation by the bacteria responsible for cavities and found that the sweetened version supported more bacterial acid production than the unsweetened one.1PubMed Central. Analysis of the Cariogenic Potential of Various Almond Milk Beverages using a Streptococcus mutans Biofilm Model in vitro If you care about dental health and drink almond milk regularly, unsweetened is the safer bet by a wide margin.
The “Acid-Forming” Question Is a Different Measurement Entirely
Most of the internet chatter about almond milk being “alkaline” is not about what a pH strip shows in your cup. It is about a concept called the potential renal acid load, or PRAL, which estimates how much acid or base a food produces in the body after digestion and metabolism. PRAL is calculated from a food’s protein, phosphorus, potassium, calcium, and magnesium content. Foods high in protein and phosphorus tend to score as acid-forming. Foods high in potassium, calcium, and magnesium tend to score as alkaline-forming.
Almonds are relatively rich in magnesium and calcium (especially when almond milk is fortified), and they are low in protein compared to cow’s milk or soy milk. That combination gives almond milk a negative PRAL score in most formulations, meaning it is classified as alkaline-forming. A study that analyzed 39 plant-based milk products on the German market using PRAL confirmed that the mineral profiles of these beverages strongly influence their acid-base classification.3International Journal of Food Properties. Potential renal acid load of non-dairy plant-based milk alternatives Fortification with calcium or potassium can shift a plant milk’s PRAL score significantly toward the alkaline side, which is why two almond milks from different brands can land in different categories.
So you end up with a situation that confuses people: almond milk is slightly acidic in the glass but classified as alkaline-forming once your body processes it. Both statements are accurate. They just measure different things. The pH of the liquid tells you about hydrogen ion concentration right now. The PRAL score tells you about the balance of acid and base your kidneys will handle later. Neither one, on its own, tells you very much about your health.
Your Body Does Not Care About the Alkaline Diet
The reason PRAL scores get so much attention in wellness circles is the “alkaline diet” hypothesis, which claims that eating acid-forming foods leads to chronic low-grade acidosis, calcium loss from bones, and eventually osteoporosis, cancer, or other diseases. Under this framework, choosing almond milk over cow’s milk would be protective because it shifts your dietary acid load in the alkaline direction. The hypothesis has been around for decades and remains popular online. The evidence behind it, however, has not held up well.
Your blood pH is maintained within an extremely tight range, around 7.35 to 7.45. The body achieves this through a system that operates on a scale most people underestimate. Your lungs blow off carbon dioxide continuously, and your liver and kidneys handle bicarbonate disposal. The throughput is enormous: metabolism of a typical diet generates roughly a mole of bicarbonate per day from about 100 grams of protein, and the body clears it without any meaningful shift in blood pH.4PubMed. Metabolic aspects of the regulation of systemic pH The idea that a glass of almond milk versus a glass of cow’s milk could meaningfully change your systemic pH is not consistent with how powerfully your body regulates that number.
The specific claim that an acid-forming diet pulls calcium from bones has been tested directly. A meta-analysis of balance studies found that while higher dietary acid load does increase calcium in the urine, this does not translate to net calcium loss from the body or to any measurable change in bone resorption markers.5PubMed. Meta-analysis of the effect of the acid-ash hypothesis of osteoporosis on calcium balance The extra calcium in the urine appears to come from increased intestinal absorption, not from bones dissolving. The researchers concluded that promoting an alkaline diet to prevent calcium loss is not justified by the evidence. A broader review of the acid-base and bone literature acknowledged that data exists on both sides but noted that recent high-quality analyses have increasingly undermined the hypothesis.6PubMed Central. Acid Balance, Dietary Acid Load, and Bone Effects-A Controversial Subject
None of this means almond milk is bad for you. It just means that choosing almond milk because it is “alkaline-forming” is solving a problem your body already solved without your help. If you prefer almond milk for its taste, its calorie profile, or because you avoid dairy, those are perfectly good reasons. The alkaline label adds nothing actionable.
How Almond Milk Stacks Up Against Other Milks
If you are comparing options at the grocery store, the pH differences between milks are real but small in practical terms. Among plant-based milks, almond milk consistently measures at or near the top of the pH scale. In the UHT comparison study, it outranked soy, oat, rice, and coconut drinks in pH.2PubMed. A comparison of the quality of ultra-high-temperature milk and its plant-based analogs Coconut and rice drinks tended to be the most acidic of the plant-based group. Cow’s milk usually lands around 6.5 to 6.7, similar to unsweetened almond milk.
On the PRAL side, the picture shifts. Cow’s milk has a positive PRAL score (acid-forming) because of its high protein and phosphorus content. Soy milk, with its higher protein, also tends to score closer to neutral or slightly acid-forming depending on fortification. Almond milk and oat milk generally score negative (alkaline-forming), though the exact number depends heavily on whether calcium, potassium, or magnesium have been added.3International Journal of Food Properties. Potential renal acid load of non-dairy plant-based milk alternatives Brand-to-brand variation within a single category can be as large as the differences between categories, which is one reason blanket statements about “almond milk is alkaline” oversimplify the picture.
Kidney Stones and Oxalate Content
One area where the chemistry of almond milk genuinely matters for health has nothing to do with acid-base balance. Almond milk has the highest oxalate concentration among commonly available plant-based milks. One analysis found that a popular brand of original almond milk contained about 27 milligrams of oxalate per cup, substantially more than oat, rice, soy, or macadamia milk.7PubMed Central. Plant-Based Milk Alternatives and Risk Factors for Kidney Stones and Chronic Kidney Disease Oxalate binds with calcium in the kidneys to form calcium oxalate stones, the most common type of kidney stone.
If you have a history of kidney stones or have been told you are at elevated risk, this is a more meaningful consideration than whether almond milk is acid-forming or alkaline-forming. The same study noted that oat, macadamia, rice, and soy milk compare favorably with dairy milk in terms of kidney stone risk factors, while almond and cashew milk carry more potential risk.7PubMed Central. Plant-Based Milk Alternatives and Risk Factors for Kidney Stones and Chronic Kidney Disease Drinking a splash of almond milk in your coffee is unlikely to cause problems, but if almond milk is your primary fluid throughout the day, and you are stone-prone, it is worth discussing with your doctor. Other plant milks may be a better fit.
What Happens When Almond Milk Is Fermented
Almond milk is increasingly used as a base for fermented products like kefir and yogurt alternatives. Fermentation changes the acidity picture substantially. When kefir cultures go to work on almond milk, they produce lactic acid, acetic acid, and citric acid, all of which drop the pH well below the starting point of the unfermented milk.8PubMed Central. Use of Almond Milk, Almond Skin and Plant Based Probiotics on Newly Developed Kefir: Physical, Chemical, Microbiological, and Functional Properties The resulting product is genuinely acidic in the same way that dairy yogurt is acidic, typically in the pH 4 to 5 range. These organic acids are what give fermented almond milk its tangy flavor and also contribute to its shelf stability.
This is worth knowing because someone who chose almond milk for its near-neutral pH might not realize that the fermented version is a very different product chemically. If you are managing acid reflux or have been advised to avoid acidic foods, plain unsweetened almond milk is a reasonable choice, but almond milk kefir or almond milk yogurt belongs in a different category. The fermentation process also changes the nutrient profile, increasing certain B vitamins and potentially improving mineral bioavailability, but it does so at the cost of raising the acidity to levels comparable to fruit juice.
Almonds Themselves and Gut Acidity
Whole almonds behave differently from almond milk in the digestive tract, and some of the confusion about almond milk’s acid-base properties comes from conflating the two. A randomized controlled trial in overweight and obese adults found that daily almond consumption significantly decreased fecal pH compared to a control group.9PubMed Central. Almond consumption affects fecal microbiota composition, stool pH, and stool moisture in overweight and obese adults with elevated fasting blood glucose: A randomized controlled trial A lower fecal pH generally reflects more microbial fermentation of fiber and prebiotics in the colon, which is considered a marker of a healthier gut environment. The effect likely comes from the fiber and polyphenols in whole almonds, components that are largely removed during the straining process that produces commercial almond milk.
This distinction matters if you see claims online that “almonds alkalize the body.” Whole almonds may have a negative PRAL score (alkaline-forming from a kidney perspective), while simultaneously making the colon more acidic through fiber fermentation. And the almond milk sitting in your fridge has had most of that fiber stripped out, so it would not be expected to produce the same gut effects. The oversimplified label of “acidic” or “alkaline” falls apart when you realize the same food can push pH in opposite directions in different parts of the body.
When Acidity Actually Matters for Almond Milk
For most people, the acidity or alkalinity of almond milk is a non-issue medically. Your body handles the acid-base load from any normal food without breaking a sweat. But there are a few practical scenarios where the pH of what you drink does matter in a direct, physical way.
- Acid reflux: If you have gastroesophageal reflux disease, the pH of a beverage when it hits your esophagus matters. Unsweetened almond milk at 6.5 is unlikely to irritate an inflamed esophagus, which makes it a popular dairy substitute for people managing reflux. Sweetened almond milk at 4.5 is a different story and could contribute to discomfort.
- Tooth enamel: As noted above, sweetened almond milk falls below the enamel-erosion threshold. If you nurse a bottle of sweetened almond milk at your desk all morning, you are bathing your teeth in a mildly erosive solution. Unsweetened versions are not erosive.
- Mixing with coffee: Almond milk sometimes curdles when added to hot, acidic coffee. This happens because the coffee’s low pH causes the proteins in the almond milk to coagulate. Using barista-blend almond milk (which contains stabilizers) or letting the coffee cool slightly before adding the milk helps prevent curdling. The curdling is a cosmetic and textural issue, not a health concern.
- Cooking and baking: In recipes that rely on an acid-base reaction for leavening (like combining baking soda with buttermilk), unsweetened almond milk may not be acidic enough to activate the baking soda fully. You may need to add a splash of vinegar or lemon juice, or use baking powder instead.
These are the situations where the pH of almond milk makes a tangible difference in your day. The broader alkaline-diet framing, where choosing almond milk over cow’s milk is supposed to protect your bones or prevent disease, does not hold up under scrutiny. If you enjoy almond milk, the unsweetened version is a low-calorie, near-neutral liquid that works well for most purposes. Just check the label if oxalate is a concern for you, and skip the sweetened varieties if your teeth or your esophagus are already giving you trouble.