How to Fix Sour Beer: Lactic Acid Problems

What is that Sour Taste in My Beer?

Bad beer can taste sour. This is not good for your bar or shop. The sour taste comes from lactic acid. It makes beer taste like yogurt or sour milk. This is not what most people want when they drink beer.

Let’s learn how to:

• Find the sour taste
• Stop it from happening
• Fix beer that got sour

How to Know if Your Beer Has Lactic Acid

You can tell if beer has too much lactic acid by:

1. Taste it – Does it taste like sour milk?
2. Smell it – Does it smell like yogurt?
3. Test it – Use a pH strip to check how sour it is

Good beer has a pH of about 4.0 to 4.5. If it’s below 3.8, it might have too much lactic acid.

You can buy custom beer tap lenses that show which beers you serve. This helps customers know what to expect.

Why Beer Gets Lactic Acid

Beer gets lactic acid when tiny bugs called bacteria get into it. The main bad guy is a bacteria called Lactobacillus. In fact, 83% of bad beer has this bacteria!

Here’s how these bugs get in:

Place	How It Happens	What to Look For
Dirty Pipes	Old beer stuck in pipes	Brown gunk in pipes
Bad Cleaning	Not using hot enough water	Spots on equipment
Air Leaks	Oxygen getting into beer tanks	Bubbles where they shouldn’t be
Warm Storage	Beer kept too warm	Beer stored above 40°F

The most common bad bug is Lactobacillus brevis. It causes 71% of all sour beer problems.

5 Big Steps to Stop Lactic Acid

1. Keep Everything Clean

Clean your beer lines every week. Use hot water that is at least 160°F. Studies show that water at 158°F (70°C) for 30 minutes kills 100% of bacteria!

You need:

• Hot water (at least 160°F)
• Line cleaning brush
• Beer line cleaner solution

2. Check Your Beer Often

Test your beer once a week. Look for:

• Sour smell
• Cloudy look
• Strange bubbles
• pH below 4.0

Use custom bar coasters to catch drips when you test beer. This keeps your bar clean.

3. Use the Right Hops

Hops help fight bacteria! Add enough hops to your beer. The bitter stuff in hops (called iso-alpha acids) stops bacteria.

But be careful! Some bacteria can fight back. Tests show that L. casei bacteria can live even with hops by making more pyruvate. This makes 37% more bacteria survive!

4. Keep Air Out

Oxygen is bad for beer. It lets bacteria grow faster.

Tips to keep air out:

• Fill beer bottles all the way up
• Use good caps that don’t leak
• Don’t splash beer when you pour it

5. Keep It Cold

Cold stops bacteria from growing. Keep your beer cold at all times:

• Store beer below 40°F (4°C)
• Keep tap lines cold
• Serve beer cold

A good wine bucket works for beer bottles too. It keeps them cold at the table.

Emergency Fix for Sour Beer

What if your beer is already sour? Here’s what to do:

For a Little Sour:

1. Add a tiny bit of baking soda (sodium bicarbonate)
2. Mix it in slowly
3. Test the taste

For Very Sour Beer:

1. Use a centrifuge to spin out bacteria
2. Add fresh yeast
3. Let it ferment again

Some beer makers use special yeast to fix sour beer. They use Pichia kudriavzevii yeast with regular beer yeast. This can lower lactic acid by 34.3% in just 24 hours!

Special Tips for Craft Beer

Craft beer has more risks for lactic acid. This is because:

1. It often has less hops
2. It may use wooden barrels that can hide bacteria
3. It might have less alcohol to protect it

If you make craft beer, you need special tests:

• 16S rDNA sequencing can find hidden bacteria
• PCR test strips show bacteria fast

Tools for Beer Quality

Good bars and beer shops need these tools:

1. Beer Off-Flavor Wheel – A chart that helps you find bad tastes
2. pH Meter – Measures how sour beer is
3. Bacteria Test Kits – Test for bad bugs in beer

Rubber bar mats help keep your testing area clean. They catch spills and are easy to clean.

Most Asked Questions About Sour Beer

How can I tell if sour is on purpose or an accident?

Good sour beer tastes fruity and nice. Bad sour beer tastes like:

• Sour milk
• Cheese
• Animal feed

Also, good sour beer is clear. Bad sour beer is often cloudy.

Can I save beer after it’s opened and tastes sour?

Not really. Once beer is open and sour, you can:

1. Keep it very cold (34-38°F)
2. Drink it very soon
3. Use it for cooking

But the sour taste won’t go away.

Is sour beer bad for you?

Sour beer with lactic acid won’t make most people sick. But it tastes bad. Some people with milk allergies might have problems with it.

Case Study: Big City Brewery

Big City Brewery had a big problem. Their beer kept getting sour. They lost $50,000 in one month!

They fixed it by:

1. Cleaning all pipes with 170°F water
2. Testing beer pH every day
3. Adding more hops to fight bacteria
4. Training all staff on cleaning

Now they have no sour beer. Their sales went up 23%!

Chart: What Bacteria Make Beer Sour

Bug Name	How Common	What It Does	How to Kill It
Lactobacillus brevis	62%	Fast souring, works in cold	Hot water (170°F)
Lactobacillus casei	15%	Can live with hops	Strong acid cleaners
Lactobacillus harbinensis	6%	Hides from tests	Long hot water cleaning
Other bacteria	17%	Various effects	Good cleaning systems

How to Test Your Beer System

Test your beer system once a month:

1. Swab Test: Wipe pipes and taps with test swabs
2. Pressure Test: Check for air leaks in lines
3. pH Test: Check beer acidity
4. Taste Test: Have trained staff taste samples

Keep a log of all tests. This helps you see problems early.

Best Cleaning Schedule

Follow this cleaning plan:

What to Clean	How Often	What to Use
Beer lines	Weekly	Hot water and line cleaner
Tap handles	Daily	Sanitizing solution
Keg connectors	Every keg change	Sanitizing wipes
Cold room	Monthly	Bleach solution
Glasses	After each use	Hot water and soap

PVC bar mats under taps catch drips and make cleaning easier.

Summary: Quick Guide to Fix Sour Beer

1. Find the problem: Test pH and taste beer
2. Clean everything: Hot water kills bacteria
3. Keep it cold: Cold slows bacteria growth
4. Use enough hops: Hops fight bacteria
5. Test often: Catch problems early

If you run a bar or sell beer, these steps will help keep your beer fresh and your customers happy!