I use RO water and DME. Are the nutrients in the DME enough, or should I be adding something?
I always use a small amount of nutrient in my starters.
Is it necessary? I don’t know.
Since the goal of a starter is to grow yeast, I know it won’t hurt and probably helps.
A pinch of nutrient won’t hurt but it’s not necessary. DME has all the nutrients needed for the yeast.
A little zinc helps. Wyeast nutrient has zinc.
Nutrient:
- Doesn’t hurt.
- Might help.
- Probably doesn’t really matter in a homebrew setting.
I don’t use it in my starters. I am generally minimalist. I may geek out in some other ways, but not with nutrient, as I truly don’t think it matters much for us.
I use 1/8 tsp of nutrient in my starters regardless of the size and also use carbon filtered tap water. Don’t know if it makes a difference, but since it can’t hurt I feel it’s good insurance.
I agree with the consensus here. Not necessary, but could be beneficial. I usually put 1/4 tsp of Fermaid O in starters. Although I don’t think I’d purchase a nutrient specifically for starters. I have it on hand because that’s what I use for meads, and so add a little to starters too.
I always add about 1/8 tsp/liter of Wyeast nutrient to starters. I’m also a repitcher and so only rarely make starters, and want to get the yeast off on a good footing. For the same reason, I use filtered tap water, not RO, for my starters. I figure all the trace minerals I can get are a good thing here, and I’m not concerned about the exact water profile like I am in my beer.
Decided to add a tiny pinch of servomyces. Lallemand says to use 2g/100L for starters, so I only had to use 0.03 grams for my starter (yes I measured it out because I like playing with water chemistry). Probably won’t do much but 0.03g is pretty cheap insurance ¯_(ツ)_/¯
Servomyces is what I use in my beer, as opposed to starters where I go cheap and shotgun-effect with Wy nut. I like it because it really only provides zinc, which as Jeff (hopfenundmalz) suggests is the one thing that’s universally deficient in even all-malt worts. In my brewing I like to only have ingredients that I know exactly what they are, and are only there for a reason I can explain. Never thought of portioning it out in a starter. But in short, I’m a fan of the stuff. Even if it isn’t cheap.
The conventional wisdom certainly is that all-malt worts are deficient in zinc. It’s in all the textbooks, etc. I’m sure it stands on solid scientific ground. It’s the main reason why nutrient is recommended.
But what about the observation that plenty of beer has been made both commercially and at home where no nutrient/zinc was added, and the beer turned out fine, fermentations went smoothly and consistently, etc.? If there wasn’t enough zinc, doesn’t it logically follow, for example, that acetaldehyde would be tasted in the finished beer? Or other off-flavors?
For me, regardless of what the textbooks say, empirical evidence conclusively points to there being plenty of zinc in unfortified wort. Perhaps there is less of a surplus of zinc relative to other minerals/nutrients, hence the “wort is deficient in zinc” mantra. But my experience and that of many, many other brewers indicates that there’s still more than enough zinc for a normal, healthy fermentation.
Can it hurt to add nutrient? The consensus seems to be probably not, as long as it’s used sparingly. It should be kept in mind that too much zinc, and many other minerals, is bad for yeast. It doesn’t take much to go from “enough” to “too much”. So my approach is to stick with the naturally occurring levels of nutrients–except when I brew my American lager, which uses 30% rice. In this case, the wort probably is truly deficient in zinc.
I’m not sure how much commercial beer has been made without zinc supplementation. In the old days it came (unintentionally) from copper alloy equipment. Later nearly every brewer started adding some supplement. Even the Germans who weren’t supposed to. No law has ever been circumvented like the so called Reinheitsgebot! Stories abound about brewers “accidentally losing” galvanized chain in the bottom of the kettle and “forgetting” to retrieve it… Now of course they have Servomyces, which is just dead yeast overdosed on zinc, so they’re nominally “only adding yeast.”
Over the years I have seen a few presentations as to how fermentations proceed better with a little zinc supplement. Note I said better, not that it would be a failure without. It is one of those little things that can add help the finished beer.
Zinc is necessary for protein synthesis and other cell functions. Without a sufficient amount, fermentation may be slower, attenuation lower, and diacetyl reduction slower or incomplete. But I suppose a little more yeast and a little more time and maybe adjustment of temperature can remedy those effects. I suspect the detrimental effects of zinc deficiency on yeast health will become more apparent over subsequent generations, so if you repitch yeast, zinc supplementation might be more important. All of this is clearly more of a concern for commercial brewers. As others say, it can never hurt. But if you don’t have nutrient on hand or don’t perceive problems with fermentation, RDWHAHB.
I must have missed that. I just perused Kunze, DeClerk, and Malting and Brewing Science and didn’t find a mention that all-malt worts are zinc deficient. Perhaps you can provide citations?
It does turn out that water composition and mashing pH can play an important part in determining if wort has sufficient zinc. Many water supplies do have trace zinc content and that can provide all that is needed for yeast nutrition. However when distilled or RO water is used in brewing, those sources are often devoid of zinc.
Malt does supply some zinc. However, that zinc is not easily accessed and brought into the wort. It turns out that keeping mash pH low will improve the solution of zinc into wort. I wouldn’t chase an unreasonably low mashing pH just to improve zinc content in the wort, but it adds to the importance of achieving a proper mashing pH…aka: a high pH is going to hurt your zinc content.
It takes exceedingly little zinc to meet yeast nutrition needs. That is a major factor in the difficulty in proper dosing. The dose for zinc sulfate heptahydrate is 1 gram per 10 to 20 BARRELS of wort. For us homebrewers, you can see how teeny our dose would need to be in a 5 gal batch. Fortunately, we can just add a dose of that mineral to a known volume of water and then proportion out that solution in our small batches.
Yeast bio-accumulate zinc in their cells, therefore another zinc source is to add yeast slurry from previous batches to the boil kettle. If I’m not mistaken, that is what the Servomyces product is. I can’t see spending money on that product when I’ve got it on hand. One problem with this approach is the potential for the boiled yeast to contribute autolysis flavors to the beer, such as rubbery or meaty flavor. There are a couple of my local breweries that clearly have this problem. Do be careful how much slurry you use and be cognizant of any autolysis flavors that might be present in the beer.
I have to admit that I don’t pay as much attention to zinc content in my wort as I should. This is especially true since I use RO as my water source. I can’t say for certain that my beers have suffered, but I have been employing the Wyeast nutrient in my kettle for the past year. Its a minor extra step that I intend to continue.
Kunze, 3.2.1.7, discusses what you reference, Martin, that the real problem is getting the zinc into the wort, as 80% is lost in mashing,* as well as some remedies. As for Servomyces, it is yeast, but grown on an exceptionally zinc-rich medium, so that tiny amounts provide plenty of bio-accumulated zinc, avoiding the problem of off flavors from the amount of normal yeast slurry you’d have to boil to provide the same amount of zinc. (I use it, as I mentioned above, when I for whatever reason only want to supplement zinc, as when using carbon filtered tap water. When I use RO, and in starters, I’m more inclined to use Wyeast nutrient because I figure other trace elements may be deficient. I should probably stop making this distinction and save money.)
*Briggs, et al., Brewing Science and Practice p. 164, puts the amount of zinc from malt that makes it into wort at just 5%, and notes that much of this is unavailable to yeast because of chelation etc.
So my galvanized boil kettle takes care of the problem? Check!
I just want to say you don’t know how happy it makes me to see professional brewing texts cited over homebrewing texts. Bless your hearts.
This should take you to a presentation by Ruth Martin of Sierra Nevada. She runs the production lab at SN.
At risk of veering slightly off course, I’ve always added nutrients to the kettle near the end of the boil. Reading the usage instructions of Fermaid K and other nutrients yesterday I discovered that they all recommend making two additions, both to the FV. Have I been wasting my time and nutrient by adding it to the boil?