Oat milk is the best alternative I've found. Most places offer it so I switched to oat milk lattes and haven't gone back.

If brewing at home, there are barista versions made specifically for coffee, but the original works too.

BLACK. DRINK IT BLACK. PUT SOME HAIR ON YOUR CHEST. DRINK IT BLACK.

Sorry about that. I have seen you say you cannot do it, but this is false. You can acquire a taste for black coffee, and it will make your coffee drinking much easier as well as improve your palate for tasting coffee. Also black coffee has only like 5 calories per cup vs 80-120 calories if you put milk in it.

Definitely Oat.
There are brands that make some specifically to emulate the flavour and texture of cow milk, often named something along the lines of "not milk".
Alternatively "Barista" variants often have a slightly raised fat content and added soy or other protein to improve foamability.

Cheapest option is to make it yourself: ~90g oats per 1000ml water

• soak and rinse oats
• blend oats, pinch of salt and water
  • don't blend too long, the mix gets a bit gluey otherwise
• strain through a cheese cloth or similar
• leave in the fridge overnight

Optional stuff:
add ~2 dates to the blender for a bit of sweetness
you can experiment with adding some cashews to the blend, or ~2 tbsp of neutral tasting oil to the blender for creamier consistency.
I heard xanthan gum can also be added to thicken the mix.

Additional coffee

Nothing? Or alternatively a single mocha shot?

But really I think the best thing would be to switch to cold brew dilute with a little water and ice and nothing more.

Almond milk. Non-sweet is an option.

Oat milk and coffee taste like they're meant to be together.

Just make sure it's a good Oat Milk. The Chobani extra creamy is my favorite.

Another idea is to drop some coconut oil into the coffee. It's different but it's something and you don't taste the coconut if you get refined oil.

Oat milk is probably the best, imho. Although don't dismiss soya milk, especially the barista versions. Personally I went cold turkey on milk in coffee years ago and never looked back. If it's lacking something without milk, try different coffee! 20 years ago I was a 100% grande latte drinker, but now I'm a freshly ground double espresso every morning.

The best alternative I found when doing this was Mylk, which is Oat based but a lot more complex a formulation than most of the just Oat milks, the whole equivalent is the best, the coffee targeted one IMO wasn't great but its worth a try also.

However ultimately I learnt how to make coffee to get more complex flavours out of it and bought speciality coffee with a decent grinder and ended up finding sweetness in the coffee itself when its brewed well. This is the rabbit hole that is worth pursing, black coffee made a variety of ways.

The other possibility is start taking in some homemade kefir, it might reduce the lactose intolerance.

Another vote from me for out and almond milk. If you do any kind of milk steaming or latte art then oat is great for that...and I just like the flavour of almond milk. It's really nice with breakfast cereals too as it adds a nice nutty flavour to everything.

There is nothing wrong with Soy milk, but with coffee you have to be careful you don't curdle it due to the high temperature.

A friend recommended Oat milk to me - I'm exactly the same as you re disliking the sweetness of lactose free - she reckons it's 'inoffensive'.

Water? Maybe shift to a “long black” style.

I know you've already gotten a bunch of answers including the going black option that I'm chiming in with... But I went through a similar process a few years back now. It took experimenting with lots of different brands until I found one that I could happily drink black. Not sure where you're located, but I found a local roaster that I've been super pleased with. It's called Goshen. It's more expensive coffee but it's also ruined a lot of other coffee for me now

I would have recommended oat, but if you say lactose free milk is already too sweet I think you’re likely to find the same with oat. Macadamia is probably the “creamiest” non-sweet alternative I’ve tried, give it a shot.

That being said, stay open to the idea of cutting back on additives altogether. I went through all sorts of things just to discover that what I liked wasn’t a particular creamer or sweetener or coffee brand - it was just lighter roasted coffee 😅

Soy milk! You can find no sugars added options

Whiskey

Brew better coffee so you don't need milk? Try some light roast beans.

I was able to cut out milk entirely first from my filter coffee and then from my moka pot coffee just by using better freshly roasted and light roasted beans.

You could try putting more coffee in. Like a bullseye or just throw in a scoop of some crystals like a pyscopath.

I went black decades ago and I never went back. Before then I was basically addicted to the sweetness and the milk.

But man, I never enjoyed coffee like I do now.

My wife takes oat milk. That seems to work for her.

I tried all the options (soy, oat, pea, lactose free) and they all sucked. If it is available, get some lactase supplement and stick with the real thing.

My vegan coworker uses sweet vanilla soy milk most days, but plain soy milk on others.

If it's too sweet, consider doing 50/50 with water.

Not all lactose free milk is equal. Look for ultra-filtered lactose free milk. The extra sweetness is caused by adding an enzyme that breaks down lactose into smaller, simpler sugars, e.g. glucose. Your body is better at tasting these sugars, and so you notice the sweetness more.

Ultra-filtered milk removes the brunt of the lactose before they add the latase enzyme, and thus there will be less simple sugar for your body to notice, resulting in a less-sweet milk.

Oat milk or water won't add the body or depth you're looking for. Depending on the particular beans, roast, and brewing method, milk might enhance the flavor profile. Similar to sugar and salt enhancing cacao. Yes, you lose nuanced notes, but no, that's not a bad thing if the overall profile is improved.

You can also try blending different milks. Maybe you like 90-10 oat/whole milk or 70:30 ultra filtered/macadamia.

Perhaps go to a local shop during a slow period and ask if you can get a cup of coffee black and a flight of alternative milks. Whatever you do, have fun doing it!

I don’t know if something like this is available where you are, but in the US there is a brand of milk owned by Coca-Cola where they filter out the sugars (lactose is a sugar), it is called Fairlife and is marketed as high protein milk. It still retains the fats and proteins and flavor of ordinary milk. It comes in a variety of fat percentages like ordinary milk for people with different dietary preferences.

My favorite plant milk is soy milk, but that isn’t as readily available out here as it used to be since conservatives decided drinking it would turn men into girls. I find oat and almond milks too watery and unsatisfying in drinks.

Try out different plant based milks (oat, soy and almond al least), but start with barista versions, they're usually higher in fat content and do not curdle as easily.

They're all very different and brands differ quite a bit, so you might need to do some experimenting. Check your go-to grocery stores and see what they have the most of. 10 brands of oat milk? Probably a good starting point.

@ada I've been a cow's milk junkie for decades, but Oatly Original is a sufficient replacement IMHO.

My recommendations are largely brand dependent and probably not available outside of germany.

I have a really good oat-almond milk at my convenience-store (Netto) around the corner. Another (LIDL) sells a very milk like oat milk (that is called No Milk). Both go for 1€ per Liter.

Rank 3 takes the sugar free variant of soy milk from alpro. Very mild taste, gives your coffee the texture your used to from milk. I even liked it when i was still drinking cows milk. They also got their own NOT Milk, which is also good. My beef with alpro are their steep prices.

I usually do oat milk, it's not bad

I had the same issue a half a decade ago and my solution was, like most of the answers I imagine you'll get here, to just get better coffee and drink it black. If you visit your local third wave cafes they should have a regular rotation of drip specialty coffee that you could try and usually they sell it too. I order from Th3rd Wave which sends me a box of different specialty coffees every month which really helps me discover what's out there, maybe you have something similar in your area?