When to Bottle? Make Better Beer By Doing Nothing

There are various schools of thought about the best time to bottle home brew. It may be later than you think.

home brew when to bottle

Generally speaking, one of the best (and easiest) things you can do to improve your home brew is leave it in the fermenter for a couple of weeks before bottling.

Doing this will give you a much tastier beer because of the extra time the yeast has to ferment the beer properly. This applies to all brewing methods, whether kit, extract or all grain.

Primary and Secondary Fermentation

During fermentation yeast convert sugars in the wort into alcohol and carbon dioxide. They also produce a number of other by-products which affect the taste of the beer.

Depending on the beer style these are more or less desirable.

A lot of ales, for instance, derive much of their character from the fruity sub-tastes produced during the beer making process.

Lagers or lighter ales, on the other hand, rely on a purity of finish as a hallmark of their style.

Yeast in Action

If you have an airlock fitted to your fermenter you’ll be able to observe the action of the yeast soon after you seal in your beer.

Bubbles of air will frantically escape through the bubbler, usually within twenty four hours. The activity will gradually die down to one or two blurps a minute, and after three days or so you probably won’t be aware of any yeast action.

Don’t jump to conclusions though – that doesn’t mean that nothing’s going on.

A bubbling airlock is not the only sign of fermentation.

Once the yeast have worked their way through the sugars, processing all of the fermentable ones and leaving behind the non-fermentables which give the sweet malty taste to beer, they move onto their second course.

Slowly they reprocess some of the fermentation by-products, starting the stage of brewing known as secondary fermentation.

Secondary Fermentation

Given enough time, yeast will clean your beer thoroughly and you’ll bottle with the best chance of a decent batch.

As a general rule of thumb around two weeks from brew day should be fine, but bear in mind that heavier, stronger beers usually require longer.

If you’re interested in finding out more about the conditioning process and what the yeast are really up to, a great explanation can be found in How to Brew by John Palmer (book / website).

Dangers of Rapid Bottling

Other than the benefits outlined above, there is another good reason for leaving your brew in the fermenter.

Assuming that they are otherwise healthy, yeast will continue to process fermentable sugars until they are gone, releasing carbon dioxide gas as they go.

Although the airlock may have stopped bubbling, the process could still be happening inside at a much slower rate.

Gas isn’t accumulating in enough quanitities to escape in a noticable way, but it’s still being generated. If you bottle before the yeast can finish, fermentation of the remaining sugars will continue inside the bottle.

If enough sugars are left in the brew the gas given out can be substantial, enough to explode your bottles. So be careful.

Checking if Fermentation is Complete

If you want to bottle as soon as possible and let the secondary fermentation take place in the bottle, there is a way to check that the risks of exploding bottles are low.

Hydrometers measure the density of water, or beer, and can tell you about the fermentation progress.

Because sugar in a liquid increases the density, a reading taken before fermentation should be higher than at the end, when the yeast have converted it into alcohol and gas.

This means that with two hydrometer readings (before and after) you’ll be able to judge whether fermentation has taken place.

Monitor Your Beer

One way to check is to compare your readings with the predicted gravities given by the recipe.

However, as most brewers don’t get exact matches of sugar profile even when following the same recipe, another way to check is to take two hydrometer reading separated by a day or so.

If the density hasn’t changed your beer’s probably done.

So, When to Bottle?

As a minimum wait until primary fermentation has completely finished, usually after four or five days.

Wait another week so the yeast can clean up your beer and your taste buds will thank your patience.

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Comments...

  1. Thank you for this article. I have been bottling after 1 week simply because gravity readings indicated fermentation was done. After reading your article, I will leave my brew in for an extra week to see the difference.

    • John

      Thanks for the comment.

      I hope it turns out well.

  2. Tim

    I too wish to thank you! I was also bottling my beer after a week or so and then drinking it about two weeks later. I noticed that the beer had a green taste (not ready). Would it be wise to move the beer to a secondary fermenter after a week? I’ve been cold crashing and clarifying with gelatin after the first week. I probably should read some more but was hoping you could give me down and dirty answer. :). Thanks

    • John

      Hi Tim,

      I wrote a bit about that here.

      In summary, I personally wouldn’t bother unless you have a good reason for doing so. You could easily leave your beer in the same fermenter another couple of weeks with no problems.

      The same goes once it’s in the bottle. It often takes a while for the flavours to settle down and mellow, unless of course a very fresh taste is what you’re after.

  3. tucker

    I’ve fermented lager for 21 days. How long now to leave cool and dark?

    • John

      I’m afraid I can’t comment as I haven’t brewed a lager myself.

      Good luck.

  4. Thank you! Was going to bottle today but will wait until next weekend. Will let you know how it goes.

    • John

      Hope it works out well.

  5. Chris

    I brewed my first batch and let it ferment for 2 weeks. I’m about to bottle and as I start into the first bottle go large chunks of sediment (1/4 inch). I imagine I don’t want these in my bottles. What should I do?

    • John

      Chris,

      It isn’t necessarily bad if a bit of sediment gets in as it does tend to fall to the bottom of the bottle. If you pour carefully it should stay there.

      However, it’s better to keep as much out of the bottles as you can.

      Are you siphoning from well below the surface of the beer? That usually helps to avoid most sediment.

      The bottling wand should filter a lot of it out as well. Are you using one?

  6. Hi
    I’ve just started home brewing and did my research first. I got a kit, Tom Caxton Lager, and the manual stated 1 week in fermenter. I saw online and you tube 2 weeks are best so was patient and I waited the 2 weeks.

    I used a 23Ltr auto siphon, with sediment catcher, and siphoned into my bottling bucket from around halfway down the brew. Just to stop any further chunks getting in. The result of waiting 2 weeks were seen from the off.

    The lager is VERY clear with no bits & has a nice aroma and tastes like beer (which is always a good sign).

    I bottled up 40 pints the same day and waited 2 weeks to do a bottle test. Tasted great and good bubbles but left another week just to give it more time.

    After 5 weeks the Final product was CRYSTAL clear a great cheap lager for first attempt.

    I’ve just brewed the Coopers Mexican Cerveza kit today so hope this works out just the same. Also added zest from 3 limes. I will keep you posted on this one.

    To the comments above I’d say be patient, give it time and sanitize EVERYTHING. Results are worth the wait.

    • John

      Hi Andy,

      Thanks for commenting. You’re right – patience is key.

      Hope the Mexican beer works out well.

  7. Wayne

    Just waiting to bottle my cider kit but its 14days tomorrow and still signs of bubbles in airlock about once a min but I am worried I’ve left it to long can anyone please help thanks.

    • John

      Sorry, I’ve never made cider but it sounds like it’s still fermenting.