Wort boiling has a special purpose in the brewing of homebrew like beer, and it’s important to be aware of why it matters, so you can exactly know what’s going on.
As you’ll see there are multiple advantages of boiling the wort and some are so important that skipping this crucial part might be a mistake from which you won’t be able to save the batch.
Of course, boiling is not necessary for every brewing method, so for instance brewing with extract doesn’t require boiling. Still, other methods including the most famous BIAB method used for homebrewing absolutely need a boil.
So, let’s see what wort boiling does to your beer!
1. Sanitation
Wort will always contain pathogens such as Lactobacillus which can cause contamination and ruin your homebrew unless you boil your wort. This is the reason why it’s absolutely essential to bring the wort to the boil and this shouldn’t be skipped because such bacteria will be present on grains, hops, and other ingredients.
Sanitation is absolutely a must, but if it was the only reason for boiling the wort then it could be done in less than 10 minutes after reaching the boiling point as it’s enough to kill all the pathogens, yet there are many other reasons for why we boil the wort.
2. We boil for the hops
When a recipe calls for hop addition it’s usually done during the boiling which lasts (30-60 minutes) as this is the time required to extract the Iso-alpha acids from the hops and release the desired aroma and bitterness. It’s not possible to extract the mentioned acids from the hops at lower temperatures as efficiently as it occurs at the boiling point.
3. Effect on OG
The longer you keep the boil, the higher the original gravity. This is due to evaporation of the water which noticeably occurs when you bring the wort to a boil and is easiest to control at this point. Although it’s possible to calculate how much water needs to evaporate during the boiling duration, it is not something that most homebrewers focus on because simply following the recipe or going for a standard 60 minutes duration will make it.
Yet if you find different boiling durations suggested in the recipes this might be for this reason. The knowledge that this way you can increase the original gravity can get helpful later in your brewing journey, but I won’t focus on it here.
4. Boiling drops Ph values
Municipal waters are rich in minerals and these minerals increase the Ph value of the water. For this reason, it’s not unusual to find values greater than 7.0 in the tap water. It’s crucial to drop these Ph values, and the values between 5.2 and 5.4 are ideal. At the moment you add grains the Ph values will automatically drop to the desired values because grains are slightly acidic compared to alkaline water, yet it’s possible to additionally drop the pH by boiling it (up to 0.2).
This might not be important if you use distilled water, but I think it’s worth a mention because usually the water people use contain at least some minerals.
Ph values are important for healthy fermentation, and the final taste profile of your beer and lower Ph values are not optimal for bacteria growth.
5. Boiling drives off DMS (Dimethyl suplhide)
DMS gives the beer that corny flavor which is undesirable and although it’s fine that beer contains some DMS it should be at moderate levels at best, so the excess should be removed or masked. There are a couple of ways how to get rid of DMS in your beer and the easiest one is through boiling.
Some other methods for masking DMS are adding more hops during the second fermentation (as lots of hops can mask DMS if the style allows a high rate of hops) or using sodium hydroxide or sodium carbonate solutions.
However, I haven’t personally tried using sodium solutions for this purpose, so can’t vouch for it but it might work indeed.
Boiling is the easiest method to drive off some DMS, so this can be achieved by keeping the wort at boiling point for 60-70 minutes.
Boiling temperature and duration
Boiling point of wort is at 212°F (100°C) and this is the ideal temperature you should maintain for the 60 minutes unless the recipe states otherwise. However, if the temperature drops a few degrees it’s okay and it won’t make much difference, but do not let the temperature drop below 204.8°F or get above 217°F.
What happens if you boil wort too long?
If you boil too long it might increase final gravity and reduce the volume of the final brew which might require you to add water to compensate for the loss. Moreover, boiling with the hops in the wort might extract too much bitterness and this will seriously affect the taste profile of the beer when it’s done fermenting. So, try not to boil longer than it is necessary to complete the recipe.
What happens if you don’t boil the wort?
So, in short, if you don’t boil the wort your beer will not be complete as there will be many important factors missing and you won’t be able to complete the recipe. What’s even worse the wort may end up contaminated.
How long can you leave wort before boiling?
It’s possible to leave the wort for 24 hours before boiling it, however, it’s always a risk, so it’s better to finish the entire process at once.
If you plan to boil the wort the next day, it’s doable, but keep in mind that the longer it stays, the better the odds of contamination are as the bacteria have more time to activate and there’s nothing to stop it. Also always cover the wort and store it in a safe, dark place like in the fridge if you plan to continue the process later.