Do commercial breweries buy in yeast?

I'm not sure whether this is perception thing, or practises have changed over the years or it's a different culture in different countries.

I did a fair amount of brewery tours about 10-20 years ago, both a proper "tour" and an ad-hoc "drop in to chat with the brewer" kind. Both ranging from local microbreweries with 2 guys working there up to Greene King. Probably 10-15 in total.

In all of them, they managed their own yeast, pitching their house yeast from batch to batch to batch indefinitely. At least half of them talked about acid washing their yeast to kill other microbes (the other half it wasn't talked about so they might or might not have done this). The smaller breweries said where they got their initial pitch yeast from (other breweries). None of them (who mentioned where they initially got their yeast from) bought it in - and certainly not on a regular basis. They were happy to give the yeast away to me as a homebrewers as brewing grows more than they need, so lots gets flushed down the drain.

Brew like a monk also mentions that the Trappist breweries repitch their own yeast (with the exception being Westvleteren who get it regularly from Westmalle).

But listening to podcasts etc and reading forums, a lot of "craft breweries" buy their yeast on a regular basis - at great cost.

Does anyone know (and I mean "know" from talking to breweries and their brewers, not just guessing) it's still the norm for UK/traditional/older breweries repitch indefinitely? Has it changed in the last 10 years since I've stopped visiting breweries? Is it just a coup that yeast labs have scored by selling yeast regularly to breweries (when it's "not really necessary")?

For mid to larger breweries it's the norm to repitch because buying in is enormously expensive. They'll stick their house yeast in a storage lab like Brewlabs in case of emergency and only order a repitch if something goes really haywire. It's worth it for them to have lab facilities and staff to monitor yeast health and genetic drift, or to send samples to a yeast lab that does that for them.

In my experience the micros are a bit more split. Those that are making hoppy pale ales/IPAs that need can use generic American ale yeasts will more often than not use dried yeast bricks, but even then will repitch for several batches. Those that are making British bitters/ales are more likely to have a house strain that they will repitch almost indefinitely like the big boys.

Agentgonzo said:

Does anyone know (and I mean "know" from talking to breweries and their brewers, not just guessing) it's still the norm for UK/traditional/older breweries repitch indefinitely? Has it changed in the last 10 years since I've stopped visiting breweries?

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If I remember I'll ask Hook Norton what they do when I am down there to brew our wedding beer.

Agentgonzo said:

But listening to podcasts etc and reading forums, a lot of "craft breweries" buy their yeast on a regular basis - at great cost.

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This is correct. The vast majority of new breweries buy in dry yeast as it means there is one less thing for them to worry about / invest in. It also has the benefit of giving them the option to brew a variety of styles using different yeasts.

However, many craft breweries eventually move on to their own house strain (e.g. Verdant, Deya) that they use for the bulk of their beers. I believe they still buy in dry yeast when needed for styles that aren't suitable for their house strain (e.g. I know Verdant use BRY-97 for their West Coast IPAs).

I've only done a couple of brewery tours & both of them had their 'own' yeast which was continuously propagated. One did say they sent a batch (post pandemic) to another local brewery who'd lost their strain.

On the handful of occasions I've brewed with commercials, some pitch dry yeast, others a repitch of the house strain. I know brewers that liase with Lallemand reps/technical team to get the right blend of dry yeast to achieve their goals, and spoken to others that buy in wet/dry and repitch for 5 or so generations.

I don't think there is one size fits all. However I can say from personal experience buying yeast of all types in ½kg packs had got much easier in the just decade, so that suggests to me there is increased demand.

With my business head on, it is also a good and classic "outsource" decision.

MashBag said:

I don't think there is one size fits all. However I can say from personal experience buying yeast of all types in ½kg packs had got much easier in the just decade, so that suggests to me there is increased demand.

With my business head on, it is also a good and classic "outsource" decision.

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It's ridiculously cheap buying that way too.

I mentioned elsewhere, I wanted a few sachets of EC1118. It was £20 for half a kilo, so I bought that instead.

Stu said:

It's ridiculously cheap buying that way too.

I mentioned elsewhere, I wanted a few sachets of EC1118. It was £20 for half a kilo, so I bought that instead.

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Really

I very quickly switched to buying half kilo packs when I got into bread making, never thought about it for beer yeast. I suppose the handling costs for packaging half a kilo is similar to 11g. So it makes sense. Must run my current stock down first but going to have a look…

Stu said:

It's ridiculously cheap buying that way too.

I mentioned elsewhere, I wanted a few sachets of EC1118. It was £20 for half a kilo, so I bought that instead.

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Yup, with a vac pac and a fridge, it keeps for years.

Stu's Brews said:

If I remember I'll ask Hook Norton what they do when I am down there to brew our wedding beer.

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Sounds great !
What are you brewing ? I love Hook Norton beers, their Flagship IPA got me started trying out Admiral in similar recipes.
I did a quick stop at the brewery when I was working nearby, it really is an amazing building - those Victorians didn't do things by halves !

Next question is then..
Where are people buying?

MashBag said:

Yup, with a vac pac and a fridge, it keeps for years.

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Exactly this. I bought my vac pac because I was buying hops in bulk. I've now found the teeny tiny bags are great for yeast.

It was a tenner from Amazon and works perfectly.

Tanglefoot said:

Sounds great !
What are you brewing ? I love Hook Norton beers, their Flagship IPA got me started trying out Admiral in similar recipes.
I did a quick stop at the brewery when I was working nearby, it really is an amazing building - those Victorians didn't do things by halves !

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The plan is to scale up this recipe - a 4.5% pale ale. Just about to finish fermenting so I'm weighing up whether to do a small dry hop or not.

Stu's Brews said:

The plan is to scale up this recipe - a 4.5% pale ale. Just about to finish fermenting so I'm weighing up whether to do a small dry hop or not.

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That looks very nice, I brewed a similar but stronger IPA bittered with Admiral which I also used for a small dry hop along with equal amount of Goldings - I'd say go for it.
I too fermented with Verdant which I really like in this style.

https://share.brewfather.app/L3UgCSd1pekfzs

Think if you're brewing constantly back to back then re-pitching yeast is more convenient. But I think you really need your own lab capability on the pro scale to keep an eye on yeast health and population so you know how much to re-pitch. Without this capability you wouldn't risk just re-pitcing without knowing exactly what you've got...on the commercial scale you need consistency and the risk of ruining a batch is far more expensive proposition.

On the homebrew scale building up starter for such small batches is pretty low risk and the chances are you're over pitching, but building up a 50 litre starter for a couple of thousand or so litre batch you need to be a bit more precise.

Hadn't looked at buying 500g yeast bricks. Might look into that to see if it is any cheaper. Certainly with my larger system with the capability of 140 litre batches I'm now looking at 10 or so packets of yeast so getting a brick should be worthwhile.

I think you might find, the price difference will cover the cost of a cheap vac pac.

Wow...a 500g brick works out at around half the price than 11g packs.

Traditional breweries like Harveys have been repitching the same yeast for decades. The yeast is probably the most significant influencer on the flavour of the beer. It would be more or less impossible to create a dry version, so they would be mad to use dried yeast. Same for breweries like Fullers.

Yup. I think it's the cost of running the lab vs buying in the yeast as an ingredient.

MashBag said:

Yup. I think it's the cost of running the lab vs buying in the yeast as an ingredient.

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I doubt very much Harveys have a lab. They are a regional brewery going back to 1790. I suspect the primary reason they don't use dried yeast is because it would be impossible to dry what is a very distinctive yeast. I'm sure it's the same for a good number of regional breweries. I say this as someone who uses dry yeast