How can I buy groceries during a mandatory 14 day quarantine?

Unfortunately, there is no official service to help you out. You're supposed to ask someone to buy stuff for you and bring it over. The Ministry assumes that everyone knows someone who is able to help.

If you don't know anyone, you have to search for alternatives. If you stay in Berlin, you should be able to find a supermarket that will deliver groceries right to your doorstep. I think this also holds for other big cities.

In smaller towns, you might be better off searching for a Facebook group or similar, where people offer their help.

Many grocery delivery services exist that will allow you to order online and have them delivered to your door.

Here's an article: Groceries Delivery Services in Berlin

It lists two delivery services and compares them

• REWE Delivery Service
• Bringmeister

EDIT: Originally this answer included a disclaimer that delivery times may be long, but it seems to have gone down. Thanks to @moink for pointing this out in the comments, some delivery services are back to being able to offer next-day delivery.

Here's another aticle: 6 Online Grocery Delivery Services in Munich to Help You Shop From Home. Wrong city but some of these services may be offered in Berlin as well.

For many cities and areas in Germany numerous groups have organised themselves to support others with buying groceries or other duties (walking the dog, filling prescriptions etc.). You can find them in social networks (e.g. facebook, nebenan.de) or by contacting e. g. the Stadtteilbüro of your district (just do a search for "Stadtteilbüro Berlin-district").

An overview of organisations that organise help in Berlin can also be found here: https://www.berlin.de/buergeraktiv/informieren/coronavirus/koordinierungsstellen/ (in German only).

Split up the job of online shopping

First, you must learn to make compromises. I used to make little buys at 8 different places, getting this or that, pursuing flavors I liked or savings. I had to drop that and focus on big grocers. Aldi/Lidl simply were not part of the plan anymore (and they realize they are getting left behind and are ramping up for curbside and delivery). That is something you must resign yourself to for the duration.

There are 2 separate parts to how online shopping works, and you can attack each part separately.

• Picking your order in the store - that means walking the shelves with a basket selecting the items you want, and having them bagged and ready to bring to the curb.
• Delivering the bags from the store to your home.

You can do both online. “Curbside” is only the first part. “Delivery” is both parts.

The first part is the “easy part”, and it’s fast work for the stockpeople who normally stock the shelves (so they know where everything is). Even in terrible March, it was no problem getting orders picked. (Well except for cold/frozen items, they had limited “curbside” freezer/fridge space, so they often disabled curbside for those items. Luckily you’re in Germany, which does not require refrigeration of eggs).

The limiting factor is delivery. That’s actually a very time-consuming operation by nature, but it’s made worse because delivery persons are using personal automobiles, which do not have a chiller compartment. So they must return to the store for each delivery. Further, most groceries actually subcontract delivery to somebody else altogether.

But the good news is, delivery is something many more agencies are geared up to do - such as the companies that do restaurant-food delivery, or even the “Uber” / taxicab gang will run a delivery if it’s the best use of their time at the moment. So you have more third-party options for the “delivery” part.

Further, this is a good role for your friends. It’s asking a lot of a friend to go to an unfamiliar store and pick 30 items. It’s asking a lot less to pick up a bagged curbside order that’s already picked.

What to watch out for

I probably don’t need to walk you through ordering on a store’s website, but there are a few things to watch out for:

• It works much, much better if you create an account, tie it to username/FB/Google/Yahoo account, and be logged in. The sites like to log you off after awhile, and if you were a cookie-only customer, it will zero your cart.

• It really matters what your local store is. The website probably geo-locates your browser and picks a “local store” for you. It’s probably the wrong one. You must override it, and watch to make sure the site doesn’t “correct” it back.

• • However, if you use a delivery service, they (or their automated system) has its own opinion about what is the closest store. You must yield to that, generally.

• Anytime you add an item to cart for delivery or pickup, that item is localized to a particular store. If you are not careful, you can wind up with items waiting for curbside pickup from 3 different stores all over the place.

• There is NO automatic transfer between stores. If Item A is out of stock at your store X, and store Y has it and you order it, that item is waiting for you at store Y, even though you paid for it on the same transaction.

• The online system is wrong about stock - a lot. Not least, a walk-in customer may take the item after it accepted your order but before the picker picks it. Then, the picker will substitute an item, or cancel the item from the order. Some sites give you a checkbox “do not substitute” or a note box to give instructions to the picker. Some sites try to interact with you “live” during the picking for your advice on substitutes etc. So be available.

• As you can see, the software infrastructure needed to do all this is simply staggering, and they threw it together fast. Yeah, it has bugs.

• If the store has “Free ____ with minimum order of €30” or whatever, hedge the order by at least 150% of that (in March, 200%). Make sure if the 2 most expensive things fall off the order, you’re still over. Otherwise ____ won’t be free.

• When an item goes out of stock, it is removed from your cart immediately, even if it’s back in stock on the day you checkout. If you have to try for days to get a delivery window, that becomes a big problem. You must keep a paper list and re-sync your online cart to the paper list.

Yeah. Nobody wants this. We do it because we have to.

Fix yourself first

Catch yourself in “seeking toward normality” and general defeatism. All due respect, you go out of your way to raise objections that really aren’t relevant in the COVID age, nor to a quarantine situation. Here are some examples:

I've been living there fore 7 years now and I have never come across anyone who actually [gets groceries delivered]

In fact, according to this article [from 2018] only 1.2%...

I assume that during the Covid-19 Pandemic sales have sky rocketed and it is now more common to purchase groceries online. However, based on personal experience and talking to my friends, it is still not as ubiquitous or as "obvious" of a choice.

See what I mean? You are basing your knowledge on how things were before COVID, which is absurd because COVID changed everything.

You say it’s not a desirable choice, yet, you admit it had an explosion of new customers during COVID. Do you figure they all were thrilled to shop for groceries online? No of course not, they had to slog through it on their computer and hated it as much as you do. But they had to do it. It was necessary.

So you knew all along the option was available, and what this boils down to is you don’t want to use it, because it doesn’t feel “normal”.

OK, catch yourself feeling that, recognize the validity of the feeling, then recognize that the world situation has overtaken you, and change tactics.

It’s much, much better today than in March, when everyone was quarantined and delivery services hadn’t ramped up yet. Took a week to even get a delivery window. So be glad for what you have.

Maybe not the answer you expected, but likely better:
You can also make a test and depending on your local state the quarantine is therefore lifted. The airports at Frankfurt (59 Euro, with quick option 139 Euro) and Munich (190 Euro) provide testing facilities. For example in Bavaria you can make the test and send it to the local "Kreisverwaltungsbehörde". The tests are only for persons which doesn't have symptoms currently. I cannot speak for Berlin, but thankfully the Bavarian government is looking into make the tests free (no cost) for returning people. I cannot say if and when the government of Berlin city will do that. Please check their website.

I think it is better for everyone when we test as much as possible anyway. So I suggest doing it even if you have to pay for it.