Problems with Rumtopf: Common Issues and Solutions

Rumtopf is a delicious, boozy German fruit compote that is usually eaten during the end-of-the-year holidays.
Rumtoph Jar
Rumtoph jar

It is made by preserving pieces of fruit that have been soaking in rum for months, to which other fruits are added in the summer and early fall. Each season brings different fruit, so the layers keep growing and the flavour keeps developing. However, despite its popularity, there are some common problems that people face when making Rumtopf.

Read on to find out common problems with rumtopf.

What is Rumtopf?

Rumtopf is a traditional German dessert made by preserving fruit in sugar and rum for several months. The name “Rumtopf” literally translates to “rum pot” in English. It is typically made in the summer months when fresh, ripe fruits are readily available.

The process of making rumtopf involves layering fresh fruit, sugar, and rum in a large pot or jar. As the fresh fruit macerates in the sugar and rum mixture, the flavours meld together and the alcohol acts as a preservative, allowing the fruit to be stored for several months. The final product is a sweet, boozy fruit compote that can be served on its own or used as a topping for cakes, ice cream, or other desserts.

While rumtopf is a delicious and popular dessert, it can be tricky to make. There are several common problems that can arise during the rumtopf-making process, including mould, fermentation, and spoilage. It is important to follow proper techniques and guidelines to avoid these issues and ensure a successful batch of rumtopf.

rumtopf stewed fruit

Common Problems with Rumtopf and Solutions

While making rumtopf can be a fun and rewarding experience, there are some common problems that can arise. Here are a few of the most common problems and their solutions:

Problem: Mould

Mould is a common problem when making rumtopf, especially if the fruit is not fully submerged in the alcohol. If you notice any mould on the surface of your rumtopf, remove it immediately.

Solution: To prevent mould from forming, make sure that the fruit is fully submerged in the alcohol. If you do notice mould, remove it immediately and make sure to sterilise the container before adding more fruit.

Problem: Fermentation

If the fruit in your rumtopf starts to ferment, it can cause the alcohol to become sour and unpleasant to drink.

Solution: To prevent fermentation, make sure that the fruit is fully ripe before adding it to the rumtopf. Also, make sure to add enough sugar to the mixture to prevent fermentation from occurring.

Problem: Too Sweet or Too Strong

If your rumtopf is too sweet or too strong, it can be difficult to drink and enjoy.

Solution: To adjust the sweetness or strength of your rumtopf, you can add more fruit or alcohol to the mixture. You can also add a little water to dilute the mixture if it is too strong.

Problem: Fruit Discoloration

If the fruit in your rumtopf starts to discolour, it can affect the taste and appearance of the final product.

Solution: To prevent fruit discoloration, make sure to use fresh, ripe seasonal fruit and add a little lemon juice to the mixture. Lemon juice can help to prevent oxidation and keep the fruit looking fresh.

How to Prevent Problems with Rumtopf

Making rumtopf can be a fun and rewarding experience, but it can also be frustrating if you encounter problems along the way. Here are some tips to help you prevent common rumtopf problems:

  • Use fresh, ripe fruit: Using overripe or underripe fruit can cause fermentation problems and spoilage. Make sure to use fresh, ripe fruit that is in season.
  • Sanitise your jars and utensils: Before starting your rumtopf, make sure to sanitise your jars and utensils to prevent contamination. You can do this by boiling your jars and utensils or running them through the dishwasher.
  • Keep the fruit submerged: It is essential to keep all of the fruit submerged in the rum to prevent spoilage. Use a small saucer or similar to keep the fruit weighed down and prevent any random pieces from floating to the surface.
  • Watch the alcohol level: Throughout the process of making the rumtopf, make sure to keep an eye on the alcohol level and top off as needed. If the alcohol level drops too low, it can cause fermentation problems and spoilage.
  • Store in a cool, dark place: Once your rumtopf is complete, store it in a cool, dark place to prevent spoilage. Make sure to check on it periodically and watch for any signs of mould or fermentation.

By following these tips, you can prevent rumtopf problems and enjoy a delicious and flavorful treat!

Answers to FAQs on Shelf Life, Storage, Pairings, and More

How Long Does Rumtopf Last?

Rumtopf is a delicious way to preserve seasonal fruits and enjoy them throughout the year. But how long can you keep it before it goes bad? The answer is, it depends on a few factors.

First, the alcohol content in rumtopf acts as a preservative, so it can last for a few months or even up to a year if stored properly. However, the longer you keep it, the more the flavours of the fruit and rum will meld together, creating a richer and more complex taste.

Second, the sugar content in rumtopf can also affect its shelf life. The more sugar you add, the longer it can last, as sugar acts as a natural preservative. However, too much sugar can also cause fermentation, which can lead to the formation of bubbles and spoilage.

So, to answer the question, rumtopf can last for several months to a year if stored properly in a cool, dark place. However, it’s best to consume it within 6 months to a year for optimal flavour and freshness.

Why Does Rumtopf Bubble?

Rumtopf is a delicious German preserved fruit in rum that is enjoyed by many people around the world. However, sometimes when making rumtopf, you may notice that it starts to bubble. Here are some reasons why this may be happening:

  • Fermentation: Rumtopf is a fermented fruit mixture, and fermentation can cause bubbles to form. This is a natural process and nothing to be concerned about.
  • Airtight container: If you are using an airtight container to make rumtopf, the gases produced during fermentation can cause pressure to build up, resulting in bubbles.
  • Temperature: If the temperature is too warm, fermentation can happen too quickly, causing bubbles to form. It is best to store rumtopf in a cool, dark place.

Overall, it is normal for rumtopf to bubble during the fermentation process. However, if you notice any mould or unpleasant smells, it is best to discard the mixture.

Does Rumtopf Need to be Refrigerated?

Rumtopf is a traditional German fruit preserve made with overproof rum. It is a delicious and versatile treat that can be enjoyed on its own or used as a topping for ice cream, cakes, and other desserts. One question that often comes up when making rumtopf is whether it needs to be refrigerated. Here’s what you need to know:

While rumtopf does not need to be refrigerated during the initial stages of preparation, it should be stored in the fridge once it is ready to eat. The reason for this is that rumtopf is a fermented product, and fermentation can continue even after the jar has been sealed. If left at room temperature, the fermentation process can cause the rumtopf to spoil or become too alcoholic.

Once the rumtopf has reached its desired flavour and consistency, it should be transferred to a clean jar with a tight-fitting lid and stored in the refrigerator. This will help to slow down the fermentation process and keep the rumtopf fresh for longer.

It is also important to note that rumtopf should be stored in a dark place, away from direct sunlight. Exposure to light can affect the flavour and colour of the fruit and the rum, and can also cause the rumtopf to spoil more quickly.

What Can You Eat with Rumtopf?


Rumtopf is a versatile and delicious treat that can be enjoyed in many ways. Here are some ideas for what to eat with rumtopf:

  • Serve it on a small plate over ice cream or pound cake for a decadent dessert.
  • Top pancakes or waffles with rumtopf for a boozy breakfast treat.
  • Use it as a filling for cakes or pastries.
  • Add it to yogurt or oatmeal for a flavorful breakfast or snack.
  • Pair it with cheese and crackers for a unique appetiser.

With its fruity and boozy flavour, rumtopf can add a delicious twist to many dishes. Get creative and experiment with different flavour combinations to find your favourite way to enjoy it.

What Size Jar Do You Need?

When making rumtopf, the size of the jar is an important consideration. You want to choose a jar that is large enough to hold all the fruit and rum, but not so large that there is too much empty space. A jar that is too large can cause the fruit to float to the top and not be fully submerged in the rum, which can cause spoilage and mould growth.

A good rule of thumb is to choose a jar that is at least 1.5 times the size of the fruit you plan to use. For example, if you plan to use 2 pounds of fruit, choose a jar that is at least 3 quarts in size. This will allow enough room for the fruit to expand and release their juices, while still being fully submerged in the rum.

It’s also important to choose a jar with a tight-fitting lid to prevent air from getting in and causing spoilage. A glass jar with a rubber gasket or a mason jar with a metal lid and ring are both good options.

Remember that rumtopf takes several weeks to months to mature, so choose a jar that is sturdy and won’t break during the fermentation process. It’s also a good idea to label the jar with the date it was started and the type of fruit used for future reference.

How to Eat Rumtopf

After months of patiently waiting for your rumtopf to be ready, it’s finally time to enjoy the fruits of your labour! Here are a few ways to eat rumtopf:

  • Serve it over ice cream or pound cake for a delicious dessert.
  • Use it as a topping for pancakes or waffles.
  • Mix it into a cocktail for a fruity twist.

When serving rumtopf, be sure to include some of the fruit and liquid in each serving. The fruit is infused with the delicious rum and sugar mixture, and the liquid is perfect for drizzling over your dessert or mixing into your cocktail.

Remember that rumtopf is quite potent, so it’s best to enjoy it in moderation. A little goes a long way!


Overall, making rumtopf can be a fun and rewarding experience, but it is not without its challenges. Here are some common problems with rumtopf that people face:

  • Using too much or too little sugar
  • Not adding enough alcohol
  • Choosing the wrong fruits
  • Not properly storing the rumtopf

These problems can result in a rumtopf that is too sweet, not alcoholic enough, or spoiled. However, with careful attention to detail and following the instructions closely, these problems can be avoided.

It is important to remember that rumtopf is a traditional dish with many variations, and there is no one “right” way to make it. Experimentation and personal preferences are encouraged. However, it is important to keep in mind the basic principles of using equal parts fruit and sugar, adding enough alcohol, and storing it properly.

If you do encounter problems when making rumtopf, don’t be discouraged. Learn from your mistakes and try again. With practice and patience, you can create a delicious and unique dessert that will impress your friends and family.

Read our post about the best sustainable slippers here

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