Homebrewing: Incremental Feeding | Craft Beer & Brewing

Reach those big beers you’re dreaming about with incremental feeding.

Incremental feeding (also called staggered feeding) is the practice of feeding your yeast additional sugar mid-fermentation. It involves reserving a portion of the fermentable sugars on brew day and adding them to the wort after fermentation has reached high Kräusen.

Why would you ever want to do this? Isn’t creating one wort and adding yeast good enough? Most of the time, yes. If you pitch an appropriately sized, healthy culture of yeast into well-oxygenated wort and keep the temperature within the yeast’s optimal range, then there’s usually no need to depart from the standard protocol.

However, in a couple of situations, it might make sense to give the yeast only a portion of the sugars up front and withhold the remainder for a time partway into fermentation. The most common scenarios include the following:

  • Your selected yeast strain benefits from such a regimen.
  • You can’t build a large enough yeast population through standard propagation methods (starters).

The first of these is quite rare because there are very few strains of yeast that may benefit from incremental feeding, and they’re almost exclusively Belgian in origin. Wyeast 3787 (Trappist High Gravity™), for example, has on occasion been reported to stall before consuming all of the available sugars. Because many of the styles one might ferment with this yeast include a good measure of simple sugar, one way to ensure full attenuation is to initially pitch into all-malt wort and then add the simple sugars after fermentation has really gotten going.

The second situation is probably more common and may rear its ugly head when you brew high-gravity ales or mid-to-high-gravity lagers (if you cold pitch). Sometimes you need more yeast than you can realistically propagate at home using your standard equipment, even if you use a flask and stir plate.

To learn more about the Care and Feeding of Yeast, check out Craft Beer & Brewing’s online class.

One solution is to propagate as much yeast as you can and then estimate how much wort that population would optimally ferment. Pitch your yeast colony into that volume of wort on brew day, and save the remainder of the wort for a later addition. Keep the incremental addition as cold as you can (frozen if possible) and then reboil and chill it before adding it at high Kräusen.

Incremental feedings are not common, and it’s entirely possible you’ll never need to use this technique. But it’s a viable solution when you need lots of yeast cells and you can’t afford to let them give up on the job.

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